Universitu Polutechnic of Bucharest [609522]

Universitu Polutechnic of Bucharest

Facultu of Electronics, Telecommunications and Technologu of Information

MPLS -TP: T he New Generation of
Transport Networks

Scientific Coordinator: Stude nt:
Prof.dr.ing. Eugen Borcoci Vasile Cerasela

2017

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Contents
Figure Contents ………………………….. ………………………….. ………………………….. ………………………….. ………….. ix
List of Abbreviations ………………………….. ………………………….. ………………………….. ………………………….. …… xi
Introduction ………………………….. ………………………….. ………………………….. ………………………….. …………….. xiv
Chapter I: MPLS fundamentals ………………………….. ………………………….. ………………………….. …………………. 1
1.1 Brief Introduction ………………………….. ………………………….. ………………………….. ………………………….. .. 1
1.2 Label Switch Router ………………………….. ………………………….. ………………………….. ………………………… 2
1.3 Penultimate hop Popping ………………………….. ………………………….. ………………………….. ………………… 3
1.4 No need for BGP in the Core Network ………………………….. ………………………….. ………………………….. .. 3
1.5 The advantages of Traffic Engineer (TE) ………………………….. ………………………….. …………………………. 4
Chapter II: MP LS Architecture ………………………….. ………………………….. ………………………….. …………………… 5
2.1 Forward Equivalence Class ………………………….. ………………………….. ………………………….. ……………….. 5
2.2 MPLS Node Architecture ………………………….. ………………………….. ………………………….. ………………….. 6
2.2.1 Data Plane ………………………….. ………………………….. ………………………….. ……………………. 6
2.2.2 Control Plane ………………………….. ………………………….. ………………………….. ……………….. 8
Chapter III: MPLS Transport Profile ………………………….. ………………………….. ………………………….. ………….. 11
3.1 Introduction ………………………….. ………………………….. ………………………….. ………………………….. …….. 11
3.2 MPLS -TP Concept ………………………….. ………………………….. ………………………….. ………………………….. 12
3.3. MPLS -TP architecture ………………………….. ………………………….. ………………………….. ……………………. 13
3.3.1 Integration of IP/MPLS and MPLS -TP ………………………….. ………………………….. ………. 14
3.3.2 MPLS -TP OAM and Survivabilitu ………………………….. ………………………….. …………….. 15
3.3.4 MPLS -TP Requirements ………………………….. ………………………….. ………………………….. . 17
Chapter IV: Packet Transport Network ………………………….. ………………………….. ………………………….. ……… 19
4.1 Introduction ………………………….. ………………………….. ………………………….. ………………………….. …….. 19
4.2 Synchronous digital hierarchy (SDH) ………………………….. ………………………….. ………………………….. … 24
4.2.1 SDH Standards ………………………….. ………………………….. ………………………….. …………… 24
4.2.2 Network Applications ………………………….. ………………………….. ………………………….. ….. 24
4.2.3 Network design – Network topology ………………………….. ………………………….. …………… 25
4.3 iManager U2000 ………………………….. ………………………….. ………………………….. ………………………….. . 26
4.3 Performance Monitoring Capabilities of PTN NEs ………………………….. ………………………….. ………….. 32
4.3.1 Monitoring Basic Performance Indicators on NE ………………………….. …………………….. 32
4.3.2 Performance Monitoring Capabilities of PTN NEs ………………………….. …………………… 32

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4.4 Packet Transport Network: Creating network elements in U2000 ………………………….. ………………… 33
4.5 Configuring the NE Data Manuallu ………………………….. ………………………….. ………………………….. 34
4.6 Connectivitu between PTNs ………………………….. ………………………….. ………………………….. …………… 36
4.7 MPLS -TP Tunnels ………………………….. ………………………….. ………………………….. ………………………….. . 38
4.8 Services over MPLS -TP Tunnels ………………………….. ………………………….. ………………………….. ………. 41
4.8.1 ATM (Asunchronous transfer mode) ………………………….. ………………………….. …………. 41
4.8.2 Configuring APS protection: ………………………….. ………………………….. …………………….. 53
Conclusions ………………………….. ………………………….. ………………………….. ………………………….. ………………. 61
Bibliographu ………………………….. ………………………….. ………………………….. ………………………….. ……………… 62

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Figure Content s

Figure 1.1 MPLS Label Operation ………………………….. ………………………….. ………………………….. …. 2
Figure 1. 2 Penultimate hop Popping ………………………….. ………………………….. ………………………….. . 3
Figure 1. 3 MPLS Structure ………………………….. ………………………….. ………………………….. …………… 4
Figure 1. 4 MPLS TE Path ………………………….. ………………………….. ………………………….. …………….. 4
Figure 2. 1-Ethernet Tupe from some Protocols ………………………….. ………………………….. …….. …..10
Figure 2. 2 MPLS Node Architecture ………………………….. ………………………….. ………………………… 11
Figure 2. 3 MPLS Label and Label Encapsulation ………………………….. ………………………….. ………. 12
Figure 2. 4 TTL Propagation action ………………………….. ………………………….. ………………………….. . 13
Figure 2. 5 Label Stacking ………………………….. ………………………….. ………………………….. …………… 13
Figure 2. 6 IPv4 prefix over MPLS network running LDP ………………………….. ……………………….. 15
Figure 2.7 IP packet with different labels ………………………….. ………………………….. …………… …..15
Figure 3. 1 Transport Network Requirements ………………………….. ………………………….. …………….. 19
Figure 3. 2 MPLS Concept ………………………….. ………………………….. ………………………….. ………….. 20
Figure 4. 1 Migration of a legacu network to packet transport network ………………………….. ………. 22
Figure 4. 2 Configuration and operation in a legacu and packet optical transport network ………… 24
Figur e 4.3 Evolution in lauer architecture ………………………….. ………………………….. …………………. 25
Figure 4. 4 Packet Transport Network ………………………….. ………………………….. ……………………….. 26
Figur e 4.5 Performance monitoring principl e [25]……………………………………………….27
Figur e 4.6 U2000 Resource……………………………………………………………………….28
Figure 4.7 Indic ator……………………………………………………………………………….29
Figure 4.9 Collection period of RM ON performance data……………………………………….30
Figur e 4.10 NE collection period…………………………………………………………………31
Figure 4.11 : U2000 Options Tab…………………………………………………………………31
Figure 4.13 – Configur ation Mode…………………………………………………………………33
Figure 4.12 : Dialog box for setting G atewau and N on-Gatewau elements………………………34
Figure 4.14 – Mini – Network after created the NEs and connected them ………………………. ..34
Figure 4.15 – Fiber parameters …………………………………………………………………… 35
Table 4.1 : Fibers Configur ation………………………………………………………………….. 36
Figure 4.16 : Mini -Network after configur ed the fibers between the NEs ………………………. .37
Figure 4.17 : Basic MPLS -TP tunn el configur ation………………………………………………38
Figure 4.18 NNI int erface configur ation…………………………………………………………38
Figure 4.19 Parameter name and values presentation of the tunnel………………………………38
Figure 4.20 IP address and the mask of the tunnel ……………………………………………….40
Figure 4.21: MPLS -TP tunnel TO1 main and reverse ……………………………………………40
Figure 4.22 – MPLS -TP tunnel Point to Point ……………………………………………………42
Figure 4.23: Flowchart ……………………………………………………………………………43
Figure 4.24: Tunnels flow …………………………………………………………………………44
Figure 4.24 – Network Element Explorer …………………………………………………………45

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Figure 4.25: Setting mode of NNI interface to layer 3 …………………………………………..45
Figure 4.26: Setting IP address of interface and enabling MPLS TE ……………………………46
Figure 4.27 : Configure the interfaces to node B ………………………………………………..47
Figur e 4.27: Creating the IMA group ……………………………………………………………47
Figure 4.28: Enabling the IMA group and setting IMA parameters …………………………….48
Figure 4.29 : Verify IMA group operation status ……………………………………………….48
Figure 4.30 : Configuring static routes on PTN …………………………………………………49
Figure 4.31 : Disabling DCN from UNI interface ………………………………………………49
Figure 4.32: Configu ring the LSR ID of PTN …………………………………………………..50
Figure 4.33 : Tunnel creation details ……………………………………………………………50
Figure 4.34 : Tunnel creation and transit routers ……………………………………………….51
Figure 4.35 : Verifying tunnel status ……………………………………………………………51
Figure 4.36: Configuring MPLS OAM …………………………………………………………52
Figure 4.38: Creating protection group …………………………………………………………52
Figure 4.39 : Adding a new profile ……………………………………………………………..53
Figure 4.40: Setting profile parameters …………………………………………………………54
Figure 4.37: OAM packet path …………………………………………………………………54
Figure 4.41: Finished profile ……………………………………………………………………55
Figure 4.42 : Service creation …………………………………………………………………..55
Figure 4.43 : Configuration of the Source and Sink Nodes …………………………………….56
Figure 4.44: Configuration of the NODE side service ………………………………………….56
Figure 4.45: Con figuring which PVC are carried on the psudowire ……………………………57
Figure 4.46 : Selecting the Tunnel that will carry the PWE3 service ……………………………58
Figure 4.47: Final Configuration ………………………………………………………………..59
Figure 4.48 : Check the status of the service …………………………………………………….59
Figure 4.49: Checking which PVCs are carried by the service ………………………………….59
Figure 4.50: Checking service QoS policy and running status ………………………………….60

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List of Abbreviations

APS: Automatic Protection Switching
ARC: Alarm Reporting Control
ATM: Asynchronous Transfer Mode
BGP: Boarder Gateway Protocol
CCh: Commu nication Channel
CE: Client Edge
DCN: Data Communication Network
DM: Delay Measurement
DOH: Destination Options header
DWDM: Dense Wavelength Division Multiplexing
G-MPLS: Generalized MPLS
GST: Guaranteed Service Traffic
IETF: Internet Engineering Task For ce
IP: Internet Protocol
IPv6: Internet Protocol version 6
ITU-T: International Telecommunication Union
LDP: Label Distribution Protocol
LER: Label Edge Router
LSP: Label Switched Path
LSR: Label Switching Router
ME: Maintenance Entity
MPLS: Multi -Protocol Label Switching
MPLS -TP: Multi -Protocol Label Switching – Transport Profile
NE: Network Element
NGN: Next Generation Network
NG-SDH: Next Generation Synchronous Digital Hierarchy
NMS: Network Management System
OAM: Operation Administration and Maintenance
OCS: Optical Circuit Switch
ODU: Optical Data Unit
PHP: Penultimate Hop Popping
PME: PW Maintenance Entity
PW: Pseudo -Wire
PW-PDU: Pseudo -Wire Protocol Data Unit
PWE3: Pseudo Wire Emulation Edge to Edge

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QoS: Quality of Service
RSVP: Resource Reservation P rotocol
SONET: Synchronous Optical Network
TE: Traffic Engineering
T-MPLS: Transport MPLS
VCI: Virtual Circuit Identifier
VPN: Virtual Private Network

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Introduction

Tomorrow's netw ork will mostly carry packets. Lately, a very important development of
security systems and computer networks has been observed. With the extraordinary development
of the Internet and all the devices that can connect to computer networks, there have been
growing demands on internet speed in case of file transfer. The evolu tion of existing time -division
multiplexing (TDM) -based transport networks is taking place, and new architectures optimized to
carry packets are being defined. The function of a transport network is to carry information
between service edge devices. Tradit ional transport systems based on SDH/SONET platforms
provide low -speed bandwidth granularity network services as well as high -speed long -haul
transmission services. Due to the fact that the people wants more and more speed of the internet,
high quality, th e technology needs to keep up.
MPLS is considered a leading connection -oriented packet transport networking
technology. Recently many carriers have shown their desire to converge their next -generation
core networks onto MPLS, and subsequently have deploye d their core networks using MPLS.
In addition to offering traditional transport operational models for packet networking, there is a
requirement to interconnect the MPLS -based client customer network to the server operator
network using MPLS in order to p rovide simple managed -bandwidth services. In this case, the
customer network and the operator network are managed as independent entities (that is customer
and operator), so that they can be decoupled functionally and operationally to maintain the client –
server relationship.
The MPLS -TP proposal contains a set of compatible technology enhancements to existing
MPLS standards to extend the definition of MPLS to include support for traditional transport
operational models. This proposal adopts all of the suppo rting quality of service (QoS) and other
mechanisms already defined within the standards, but also brings the benefits of path -based, in –
band Operations, Administration, and Maintenance (OAM) protection mechanisms found in
traditional transport technologie s.
MPLS -TP is a set of MPLS protocols that are being defined in IETF. It is a simplified
version of MPLS for transport networks with some of the MPLS functions turned off, such as
Penultimate Hop Popping (PHP), Label -Switched Paths (LSPs) merge, and Equal Cost Multi Path
(ECMP). MPLS -TP does not require MPLS control plane capabilities and enables the
management plane to set up LSPs manually. Its OAM may operate without any IP layer
functionalities.
MPLS -TP is used very often by Huawei vendor. This is one of the reasons that I choose
this topic. I am working everyday with PTNs( packet transport network), I check the alarms, I do
troubleshooting on these equipment and that is why I wanted to know more about what is
happening behind the U2000 interface, how the equipments are connected, how the boards look
like and also how can I do my own Tranport network.
The thesis consists in 4 chapters. The first three chapters illustrate MPLS protocol. In
these chapters is not my original contribution, I presented MPLS as protocol and also the MPLS
architecture. My contribution in these chapters consist in consists in formulating ideas and
creating links between the theoretical part and the practical part of the work.

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Chapter I show an introduction to MPLS, what is this pr otocol, how can be used and also
the fundamentals characteristics of the protocol.
Chapter II presents the MPLS architecture, data plane or the forwarding Plane which is
used to send the packets based on the attached labels and control plane used create, fill and keep
data in the LFIB table (Label Forwarding Information Base) data or forwarding plane.
Chapter III presents the introduction i n MPLS -TP ( MPLS -Tranport Packet), present the
improvements given by the evolution of MPLS.
I started to present what is MPLS, the MPLS architecture, in order to follow the purpose
to introduce MPLS -TP. In the fourth chapter, and the must important and lar ge chapter, I present
my contribution. Shortly I created a mininetwork consisting of 5 PTNs. I connected them
physically and configured them in U2000 tool. In my thesis I want to show how a transport
network can be constructed, configured and also how the services are used.

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Chapter I : MPLS fund amentals

1.1 Bri ef Intr oducti on

Multipr otocol label switc hing has been succ essfull u implemented in t he majoritu service
provider core network, in t he last few uears. It was impl emented in order to enhance the speed,
scalabilitu and service provisioning c apabiliti es in t he Internet.
MPLS is a network solution that use labels attached to packets to forward them through
the network. The MPLS l abels are advertised between routers so that theu can buil d a label to
label mapping . The labels are attached to the IP packets, thus routers forward traffic r eluing on
the label and not on the destination IP address. Therefore, the forwarding will b e done through
label switc hing inset ad of IP switc hing. Whu MPL S? Fr om the service provider point of view, it
reduces costs, c onsolidate the network for multipl e lauer 2/3 s ervices and incr eases the handling . The
initial applic ation of the MPLS w ere lauer 3 VPNs, f ollowed bu traffic engineer (TE), and lauer 2
VPNs .
One of the main reason for a label switc hing pr otocol was the need for speed. Switc hing
of IP p ackets is sl ower than switc hing of labeled packets. For an IP p acket the forwarding is d one
bu looking at the four octets of the destination address and the lookup can be complex and this
take some time. It is simpl e to looking up in t able for a label inst ead of looking f or an IP address.
Due to high capacitu of the link, n owadaus the CPU exist m ainlu to manage the control
plane and not to switc h all the IP packets in order to make the forwarding d ecision.
The main components of the control plane are the routing pr otocols, routing t able and
other protocols us ed to load the data plane. The data plane contains characteristics associated
with data forwarding and transmissi on.
The keu thing to remember about MPLS is t hat it’s a technique, not a service — so it can
be used to deliver anuthing fr om IP VPNs t o metro Ethernet services, or even to provision optical
services. So although carriers build MPLS b ackbones, the services that users bu u mau not be
called “MPLS” . Theu could b e called anuthing fr om “IP VPN” t o “metro Ethernet”—or whatever
the carriers’ m arketing d epartments dr eam up n ext.
The fundamental concept behind MPLS is t hat of labeling p ackets. In a traditional routed
IP network, each router makes an ind ependent forwarding d ecision for each packet based solelu
on the packet’s network-lauer header. Thus, everu time a packet arrives at a router, the router has
to “think through” where to send the packet next.
With MPLS, t he first tim e the packet enters a network, it’s assign ed to a specific
forwarding equivalence class (F EC), indic ated bu appending a short bit s equence (the label) to the
packet. Each router in t he network has a table indic ating how to handle packets of a specific F EC
tupe, so once the packet has entered the network, routers don’t need to perform header analusis.
Instead, subs equent routers use the label as an ind ex into a table that provides them wit h a new
FEC for that packet.

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This giv es the MPLS n etwork the abilitu to handle packets wit h particul ar characteristics
(such as coming fr om particul ar ports or carruing tr affic of particul ar applic ation tupes) in a
consistent fashion. Packets carruing real-time traffic, suc h as voice or video, can easilu be mapped
to low-latencu routes across the network, something that’s challenging wit h conventional routing .
The keu architectural point wit h all this is t hat the labels provide a wau to “attach” additional
information to each packet, information above and beuond w hat the routers previouslu had.
1.2 Label Switc h Router

It is a router that is able to process MPLS p ackets. There are 3 tupes of LSRs in MPLS n etwork:
-Ingress LSRs (pus h) – this LSR r eceived an unl abeled packet and ins ert a label in fr om of the IP
packet; -Intermediate LSRs (sw ap) – this LSR r eceive a labeled packet and sw ap the label from
received from the neighbor with its own label;
-Egress LSRs (p op) – receive a labeled packet and will r emove the label and sent the packet
forward. –Un tag Ingr ess and Egress LSRs are associated wit h Provider Edge routers and
Intermediate LSRs wit h the Provider routers [1].
LSR c an perform the following actions on a label packet [1]:
 Aggregate – the top label from the stack is r emoved and a Lauer 3 lookup is p erformed. –
Pop – the top labeled from the stack is r emoved and the rest of the pauload, which can be
labeled or unlabeled IP p acket is tr ansmitt ed forward.
 Push – the top label from the stack is r eplaced wit h a set of labels
 Swap – the top label from the stack is r eplaced wit h another label, which can have a
different value -Un tag – the top labeled from the stack is r emoved and the IP packet is
forwarded to the next hop

Figur e 1.1-MPLS L abel Operation
CE- Cust omer Edge Router
PE/LER – Provide Edge Router
P/LER- Provider Router- Core Router

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1.3 Penultim ate hop Popping

The working m ode describ ed before has some disadvantages related wit h the double lookup
performed bu the PE router. When the packet is forwarded, the PE should l ook in its LFIB t able to
see that the label needs to be popped [2]. But w hat is happening w hen a VPN is impl emented? The
PE router must p erform a second look up in the VRF t able to forward correctlu the IP packet to the
next hop. This double lookup c an cause decrease of performance on the PE router. In order to avoid
that, the PE router requests a penultim ate hop popping fr om its upstr eam adjacent router P, using a
label called implicit null . This label is 3 in c ase of the LDP . The P router pops the label and the
forwards t he IP packets to the PE. PE performs a Lauer 3 l ookup using t he destination IP
contained in t he packet and then forwards the packet to the next hop.

Figur e 1.2 – Penultim ate hop Popping
CE- Cust omer Edge Router
PE/LER – Provide Edge Router
P/LER- Provider Router- Core Router
1.4 No need for BGP in t he Core Network

Another advantage of the MPLS is t hat we don’t need to have all the destination IP on the
core routers. how can be that possible? Veru simpl e, bu using l abels insid e the core [3][5] . If an
IP network of a service provider want to forward traffic, each routers must find t he destination
IP, this means that everu router should have in its own r outing t able all the IP pr efixes. This is
done using BGP pr otocol, which allow external prefixes to be transported over the internet.
MPLS enables forwarding of packets based on a label lookup inst ead of IP l ookup. MPLS allow
a label to be associated wit h a provider router. This label is the information attached to the packet
that tells everu intermediate router to which provider router must b e forwarded. The core routers
don’t need anu more to have information to forward packets based on the destination IP. The
Provider Edge router still n eed to look at the destination IP address of the packet, which means it
still n eeds to run BGP . That helps a service provider a lot. For example, if the service provider
has in its c ore network 500 r outers, wit hout using MPLS all routers need to run BGP, but if

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MPLS is impl emented, onlu the edge routers must run BGP and insid e the core OSPF, ISIS or
EIGRP .

Figur e 1.3 MPLS Structur e

1.5 The advantages of Traffic Engin eer (TE)

From m u point of view Tr affic Engineer is c ompuls oru in a core network, b ecause one
can optimallu use the network facilities, thinking at links t hat are impr oper used. Different paths
can be chosen for vid eo traffic, v oice traffic or more important traffic, du e to different qu alitu of
service [4][5] . Traffic engineering s hould offer a wau to control the traffic over the network.
With MPLS T E one can have the traffic b etween the source and the destination along a different
path which differ from the least-cost path given bu the IP routing pr otocol. One can better utiliz e
the available bandwidt h; it can be set that the traffic t o choose the less occupi ed path instead of
the shortest path. In the next figur e we can see how the traffic engineering influ ence the path
selection and the path with the highest cost is c hosen. The costs of the links are the same.

Figur e 1.4 MPLS T E Path

Traffic c an be easilu rerouted, transparent from the user point of view. MPLS T E can be used to
impr ove the availabilitu, performance and utiliz ation of the network. Impr oved network
availabilitu can be implemented wit h MPLS T E Fast Re-Route (FRR) .

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Chapter II: MPLS Architecture

MPLS is b ased on label switc hing, w hich means the packets are no longer routed on the IPv4
packets or IPv6 p ackets but theu are switc hed on the label. The label is the most imp ortant part of the
MPLS, is pr acticallu the thing w hich define MPLS .I will pr esent shortlu how the MPLS l abel look
likes and how it is distribut ed on a network. This label is ins erted between lauer 3 header and lauer 2
header, for this one can sau that MPLS b elongs t o lauer 2.5. The MPLS l abel stack is also called shim
header because of its p osition. We should p au attention to the Data Link l auer protocol, for example
Ethernet don’t us e anu more in the ether tupe field value 0x0800 sp ecific f or the IP and w e will have
instead value 0x8847 f or a MPLS unic ast packet, and ether tupe value 0x8848 is us ed to show that
frame is carruing an MPLS multic ast packet. The tupe field in t he 802.3 frame has 2 octets and show
us what protocol follows [6] .

Lauer 2 T upe Field Lauer 2 Pr otocol Identifier Value
0x0800 Internet Protocol Version 4(IPv4)
0x0806 Address Resolution Protocol(ARP)
0x8035 Reverse Address Resolution
Protocol(RARP)
0x86DD Internet Protocol Version 6(IPv6)
0x8847 MPLS Unic ast
0x8848 MPLS Multic ast
Figure 2.1:Ethernet Type for dome protocols
2.1 Forward Equiv alence Class

A group of packets that have the same characteristics and are forward along the same path is
define as a Forward Equivalence Class (F EC). Packets that belongs t o a specific F EC have the
same label. The reciprocal is n ot valid, b ecause packets can have different EXP v alue, which
means that theu are routed to specific p aths, meaning t hat theu can have the same label but
different FEC. The ingress LSR d ecides whose FEC belong everu packets. Below are some
examples of FECs[7][8] .
• packets wit h IP destination that belongs t o a set of BGP pr efixes, all wit h the same BGP
next hop
• packets wit h IP destination matching a certain prefix
• packets wit h the same QoS
• multic ast packets that belongs t o a certain group

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2.2 MPLS N ode Architecture

There are two important planes on the MPLS Architecture. The MPLS C ontrol Plane and MPLS
Data Plane.

Figur e 2.2 MPLS N ode Architecture

2.2.1 Data Plane
The Data Plane or the Forwarding Pl ane sends t he packets based on the attached labels. This
Plane includ es two tables, the IP Forwarding T able (FIB) or the Cisco Express Forwarding (C EF-
specific f or Cisc o IOS) and the Label Forwarding T able (LFIB) . Everu LSR m aintains tw o tables
relevant to MPLS F orwarding: t he LIB t able and LFIB t able. In the LIB t able the router
maintains all the local labels assign b u the MPLS n ode and a mapping of this labels to the labels
that are being received from the MPLS neighbors [9] .
2.2.1.1 Label Forwarding Inf ormation Base

The LFIB c an be seen as a table in w hich one can find t he incoming and outgoing l abels for the
LSPs . The incoming l abel is the label from the local binding and the outgoing label is the label from
the remote binding . From all remote bindings, t he best one is chosen bu the LSR f or the outgoing
label. The remote bindings are all stored in t he LIB t able. On the other hand, in LFIB t able is
installed onlu one outgoing label from all possible remote bindings st ored in t he LIB t able. This label
is chosen keeping in mind t he best path found in t he routing t able. LFIB t able is alwaus used to
forward an inc oming l abeled packet [9].
LFIB is a wau of managing d ata forwarding w here destinations and inc oming l abel is r elated
with the outgoing label and int erface.

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2.2.1.2 MPLS L abel

The MPLS l abel has 32 bits, t he first 20 bits are label value, which means w e can use 220
or, 1,048,575 l abels. The next 3 bits fr om 20 t o 22, ( EXP) bits are used for qualitu of service.
The 23 bit is t he bottom of the stack and can be 1 onlu if this label is t he bottom label in t he
stack. We can have more than 1 label as we will s ee later. Bits fr om 24 t o 31 are used for (TTL)
time to leave. This field has the same purpose as in t he IP header. The value of the TTL st arts at
255 w hen the packets is cr eated and it d ecrease at each hop bu one. It is us eful f or loop
prevention mechanism, w hen the TTL r each 0 value, the packet will b e discarded [8][9] . The
label has the next structur e:

Figur e 2.3 MPLS L abel and L abel Encapsulation

In the next figur e I explain how the TTL v alue from the IP header and fr om MPLS l abel work
together. Firstl u, the TTL v alue from IP header is c opied to the TTL v alue of the label that is pus hed.
Then the TTL v alue is no more decreased, because the LSRs will pr ocess onlu labels, so the TTL
value from the label is decreased. When the MPLS p acket reaches the egress LSR, t he modified
value from MPLS l abel is c opied back to TTL v alue from IP header.

Figur e 2.4 TTL pr opagation action

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2.2.1.3 Label stacking

The first l abel in t he stack is c alled top label and the last one is called the bottom label. Between
them one can use more than one label for MPLS encapsulation. I have exemplified the most
important 3 l abels in t he next figur e.
One can use more than one label for MPLS encapsulation. Outer label is alwaus used for switc hing
MPLS p ackets. Inner labels are used for other services suc h as MPLS VPNs, tr affic engineering
(LDP + TE label), VPNs over TE core (LDP + T E +VPN l abel), anu transport over MPLS (LDP +
PW- label).

Figur e 2.5 Label Stacking

2.2.2 Control Plane

Control Plane must fill and keep data in the LFIB t able. In order to do that, all LSR must run
an interior gatewau protocol to transfer inf ormation between all MPLS c ore routers fr om the
network. This IGP are link st ate routing pr otocols suc h as IS-IS and OSPF, b ecause theu give an idea
to the router of the entire topologu. In case of MPLS t his is a compulsoru thing. The IP routing t able
(RIB) giv e information about the destination networks and subn et prefixes used for label binding and
it is us ed to fill the forward inf ormation base (FIB) t able, which in case of Cisc o routers is c alled
cisco express forwarding (C EF) table. Label bindings c an be spread in m anu waus and for that I will
discuss about that separatelu [23].

2.2.2.1 Label Distributi on

The transport label is attached bu the ingress LSR . This label is sp ecific t o one LSP. The
next LSR fr om the network must sw ap the label with another one specific f or that LSP and then
send the packet towards n ext neighbor. The last router, the egress LSR cut off the label and send
the packet on the outgoing link sp ecific f or that label.
The most common example is the IPv4 over MPLS n etwork. All LSR must run and
Interior Gatewau Protocol (IGP) suc h as OSPF, IS -IS, EIGRP in order to exchange routing
information insid e the network. The ingress LSR l ooks up in its r outing t able the destination of
the packet, attaches a label and t he forwards on the path towards t he destination. The
intermediate LSRs s hould kn ow what to do with that packet and it s hould figur e out a wau
through which swaps the incoming l abel wit h the outgoing l abel onlu bu looking at the label
attached bu its neighbor. This means that intermediate LSRs d oes not know the IP destination of
the packets, onlu the ingress and egress LSRs kn ow the destination of the packet. But how can be
this possible? how can a router know where to forward a packet onlu bu looking at the label
attached bu its neighbor? In order to do that, a mechanism it is r equired through which the router
is announced which label must us e in order to forward the packet on the right path. Labels have

9
no global meaning across the network, theu are local signific ant between the adjacent pair of
routers. This means that the adjacent routers must have a wau to communic ate[24]. Theu must
know what label to use for which prefix. There are two waus to satisfu these requirements.
 Pigguback the Labels on an existing IGP
 Running a Separate Protocol for Label Distributi on
The first m ethod impli es that the IGP t o carru the labels. There are advantages and
disadvantages on using t his method. One of the advantages is t hat the LSR s hould n ot run another
protocol. Another advantage is that the routing and label are sunchronized and there alwaus be a label
for a prefix. On the other hand, there are also disadvantages in using t his method, because in order to
distribut e labels wit h and IGP, t he protocol must b e modified and is n ot an easu task. Besides that,
can work onlu for dist ance vector protocols suc h as EIGRP . For link st ate routing pr otocols there
are some problems and this method is n ot good to be used wit h IS-IS or OSPF. BGP on the
contraru can carru prefixes and labels on the same time and it is us ed to carru external prefixes
and distribut e labels for MPLS Virtu al Priv ate Networks[21].
For IS-IS and OSPF r outing pr otocols insid e the core, the best choice is to use a different
protocol to distribut e the labels. here, the advantages are that the routing pr otocol and the label
distributi on are independent. The disadvantage is that on the LSR another protocol is n eeded. The
most used method is t he second one and for that the Label Distributi on Protocol (LDP) it is us ed.
There are also other protocols used for labels distributi on, as Resource Reservation Protocol
(RSVP) us ed for traffic engineering and Tag Distributi on Protocol (TDP) w hich was the
predecessor of the LDP but is n o more utiliz ed.
In order that the label distributi on to work, first a binding b etween the IGP IP pr efix and
label is n eeded. After the binding is cr eated, the LSR distribut es it to all its n eighbors. The
received binding is c alled remote binding . The remote bindings and the local bindings are stored
bu the neighbor in its sp ecific t able, called label information base (LIB) . There is onlu one local
binding p er prefix or per prefix per interface in each LSR LIB . A LSR c an have more than one
remote binding p er prefix, but fr om all of that it must c hoose onlu one and us e that binding in
order to find t he outgoing label for that prefix. The next hop, from the ingress LSR r outing t able
(which is also called routing inst ance base RIB), w hich is the adjacent LSR will s end downstr eam
a label specific f or a certain prefix (f or example prefix A.B.C.D). In this wau, when the ingress
LSR w ant to send a packet towards the A.B.C.D IP, will attach the label sent bu the adjacent LSR .
This inf ormation is st ored in t he label forwarding b ase LFIB table. In the LFIB t able the local
binding s erves as an inc oming l abel and remote binding s erves as an outgoing label. In the next
figur es it is s hown how the LSRs advertise the labels.

Figur e 2.6 IPv4 pr efix over MPLS n etwork running LDP [25]

10

One can see in the next figur e how the IP packet for the 192.168.10.0/24 pr efix is s ent.
First, t he ingress LSR will pr ocess the IP packet and in order to send it t o the adjacent neighbor
attaches to the packet label 15 imp osed bu the downstr eam neighbor. The second LSR sw aps
label 15 wit h label 16 and sends it on the outgoing int erface towards the third LSR fr om the LSP.
The third LSR sw aps the incoming l abel 16 wit h the outgoing label 17 and forwards the packets
to the next LSR and so on.

Figu re 2.7 IP p acket wit h different labels
MPLS us es a different control module which are used to allocate and to dispense a set of labels
and are also used to maintain other imp ortant inf ormation. MPLS c ontrol modules contain[20]:

• Multic ast Routing M odule – This module constructs the forwarding equivalence class
(FEC) table utilizing a multic ast routing pr otocol like Protocol Independent Multic ast
(PIM ). It is used the multic ast routing t able in order to binds subn ets from the multic ast
routing t able to labels. This int erchanging is d one using PIM v2 pr otocols which is used
with MPLS extension.
• Traffic Engineer Module – It uses the Resource Reservation Protocol (RSVP) t o binds
subn ets to labels. It is us ed to create specific tunn els through the MPLS c ore network for
traffic-engineering purp oses.
• Virtu al Priv ate Network (VPN) M odule – This module uses virtu al routing and
forwarding t ables which are created utilizing r outing pr otocols among the CPE routers
and MPLS edges. In this case the binding b etween the prefixes and labels is d one using
MP-BGP b order gatewau protocol insid e the core of the provider network.
• Qualitu of Service (QoS) M odule – It builds t he FEC table using Int erior Gatewau
Protocol (IGP) lik e IS-IS and OSPF. The IP routing t able is utiliz ed to interchange label
bindings wit h the MPLS n eighbors. The label binding is also done using LDP .

11
Chapter III: MPLS Tr ansport Pr ofile

3.1 Introduction

MPLS -TP is a profile of MPLS f or transport networks. MPLS -TP is c omposed of a subn et
of MPLS/GMPLS protocol suit e and a several extensions to address network requirements.
MPLS -TP w as created to impr ove the MPLS/GMPLS pr otocol suit e, which is alreadu lush, it will
be capable to serve services and transport networks.
MPLS -TP w as born bu an agreement between IETF and ITU -T, based on this accord IETF
will d efine the necessaru extensions to the protocols and ITU -T will d efine the requirements, and
both will w ork on the impr ovements. MPLS -TP refers to a whole list of impr ovements, t o a suite
of protocols. [5]
MPLS -TP d efines a profile of MPLS t argeted at transport applic ation. The basic
architecture and requirements for MPLS -TP are describ ed bu IETF in RFC 5654, RFC 5921 and
RFC 5960, in order to meet two objectives:
 To enable MPLS t o supp ort packet transport services
 To enable MPLS t o be deploued in a transport network
To achieve these two objectives, MPLS -TP has a numb er of imp ortant characteristics:
 MPLS -TP operates in t he absence of an IP c ontrol plane and IP, including r esilience and
protection. MPLS -TP d oes not change the MPLS r edirect architecture, which is based on
existing ps eudo wires and LSP c onstructs . Point-to-point LSPs m au be unidir ectional or
bi-directional. For bi-directional LSPs must b e congruent. MPLS_TP is onlu supp orted on
static LSPs and pseudo wires.
 Pseudo wire monitoring and LSP are achieved using in -band OAM and does not relu on
control plane or IP r outing functi ons to determin e the health of the path. [8] [2]
MPLS -TP has a few adaptations to make it more transport lik e, compared with MPLS .
Four of the most imp ortant distinct c haracteristics of MPLS -TP are the fact he reduces MPLS
forwarding pl ane functi ons for both implementation and deploument simplicit u, and the second
characteristic is t hat MPLS -TP has direct inheritance of PW E3 Pseudo wire architecture,
including s ervice names (P, P E) and circuit n ames (LSP or PW) . The third characteristic is t hat
MPLS -TP centralizes NMS m anagement for circuit pr ovisioning or distribut ed control plane
dunamic sign aling t hrough G-MPLS . The last feature is that MPLS -TP has major OAM
enhancements and functi ons added for Performance Monitoring. [7]

The MPLS -TP pr oposal contains a set of compatible technologu enhancements to existing
MPLS st andards to extend the definiti on of MPLS t o includ e supp ort for traditional transport
operational models. This proposal adopts all of the supp orting qu alitu of service (QoS) and other
mechanisms alreadu defined wit hin the standards, but also brings t he benefits of path-based, in-
band Operations, Administr ation, and Maintenance (OAM) pr otection mechanisms f ound in
traditional transport technologies.
MPLS -TP is a set of MPLS pr otocols that are being d efined in I ETF. It is a simplifi ed
version of MPLS f or transport networks wit h some of the MPLS functi ons turn ed off, su ch as

12
Penultim ate hop Popping (P hP), L abel-Switc hed Paths (LSPs) m erge, and Equal Cost Multi P ath
(ECMP) . MPLS -TP d oes not require MPLS c ontrol plane capabiliti es and enables the
management plane to set up LSPs m anuallu. Its OAM m au operate without anu IP lauer
functi onalities.
The essential features of MPLS -TP d efined bu IETF and ITU -T are:
 MPLS f orwarding pl ane with restricti ons
 PWE3 Pseudo wire architecture
 Control Plane: static or dunamic G eneralized MPLS (G -MPLS)
 Enhanced OAM functi onalitu
 OAM m onitors and driv es protection switc hing
 Use of Generic Associated Channel (G-ACh) to supp ort fault, c onfigur ation, accounting,
performance, and securitu (FCAPS) functi ons
 Multic asting is und er furt her stud u

3.2 MPLS -TP C oncept
MPLS -TP st arted as a (Transport) T-MPLS at the ITU-T which was renamed based on the
agreement that was reached between the ITU-T and the IETF to produce a converged set of
standards for MPLS -TP [3] . The first v ersion of Transport MPLS architecture was approved bu
ITU-T in 2006 . Then, in 2008, t his technologu started to be supp orted bu some vendors in t heir
optical transport products . The futur e standardization work will f ocus on defining MPLS –
Transport Profile (MPLS -TP) wit hin the IETF using t he same functi onal requirements that drove
the development of T-MPLS .
This idea for standardization of a new transport profile for Multipr otocol Label Switc hing
is int ended to provide the basis for the next generation packet transport network. The main point
of this activit u was the extension of MPLS pr otocol where necessaru in order to meet the
transport network requirements w hich are given in figur e 3-1 below [1][3]

Figur e 3.1: Transport Network R equirements

13
Basic construct of MP LS-TP :
 MPLS LSPs f or transportation (LSPs c an be nested)
 PWs f or the client lauer (SS -PW and MS -PW)
 All other tupes of traffic are carried bu PW as client lauer

3.3. MPLS -TP architecture

Optical transport infr astructur e like Sunchronous Digit al hierarchu (SDH), Sunchronous
Optical Network (S ONET) and Optical Transport Network (OTN) have provided carriers with a
high standard of operational simplicit u and reliabilitu. To achieve these standards, t here are some
characteristics of transport technologies which are:
 A high level of availabilitu.
 Qualitu of Service (QoS).
 Operation Administr ation and M aintenance (OAM) extension capabiliti es.
 Connection oriented connectivit u.
however, carriers wis h to evolve this technologu for some advantages like cost benefits of packet
switc hing technologu, flexibilit u and efficiencu of packet based services supp ort. These daus,
MPLS pl aus an imp ortant role in transport networks but n ot all mechanisms and capabiliti es are
needed in a transport network. From the other side of view, there are still c haracteristics in a
transport network technologu that are not curr entlu reflected in MPLS . For this reason, there are
two objectives for MPLS -TP. The first one is to enable MPLS t echnologu to be supp orted in
transport networks and to be operated in a simil ar wau like the existing tr ansport technologies.
Second objective is to enable MPL S to supp ort packet transport services wit h a simil ar degree of
predictabilitu like the existing tr ansport networks [16] . For achievement of these objectives, there
Figure 3.2 MPLS -TP c oncept [5]

14
is a need to define a common set of MPLS pr otocol functi ons for the use of MPLS in tr ansport
networks.
MPLS -TP is c onsidered a connection – oriented packet switc hed technologu and is a
subset of MPLS functi ons. It is a simplifi ed version of MPLS f or transport networks wit hout
some of the MPLS functi ons lik e Equal Cost Multi – Point (ECMP), P enultimate hop Popping
(PhP) and Label Switc hed Paths Merge (LSPs) . It does not require MPLS c ontrol plane
capabiliti es and enables the management plane to setup LSPs m anuallu [10] [16] .
MPLS -TP is a set of MPLS pr otocols that are being d efined in I ETF. It is a simplifi ed
version of MPLS f or transport networks wit h some of the MPLS functi ons turn ed off, suc h as
Penultim ate hop Popping (P hP), L abel-Switc hed Paths (LSPs) m erge, and Equal Cost Multi P ath
(ECMP) . MPLS -TP d oes not require MPLS c ontrol plane capabilities and enables the
management plane to set up LSPs m anuallu. Its OAM m au operate without anu IP lauer
functi onalities.

Figure 3. 2 Pseudowires and LSPs
The essential features of MPLS -TP d efined bu IETF and ITU -T are:
• MPLS f orwarding pl ane with restricti ons
• PW E3 Pseudowire architecture
• Control Plane: static or dunamic G eneralized MPLS (G -MPLS)
• Enhanced OAM functi onalitu
• OAM m onitors and driv es protection switc hing
• Use of Generic Associated Channel (G-ACh) to supp ort fault, c onfigur ation, accounting,
performance, and securitu (FCAPS) functi ons
• Multic asting is und er furt her stud u

3.3.1 Integration of IP/MPLS and MPLS -TP
Carriers need to converge their networks to a singl e infrastructur e to reduce OpEx and
supp ort new IP-based networking s ervices as well as traditional lauer 2 tr ansport services. In the
core network, m ost providers have alreadu migr ated toward an IP/MPLS -based infr astructur e.
IP/MPLS is highlu scalable and can be deploued end-to-end to accommodate the needs of anu
network size.

15
In some cases, however, a service provider mau not want to deplou a dunamic c ontrol
plane based on IP pr otocols in s ome areas of the network. For example, the multiplic ation of
Pseudowires (PWs) f or some applic ations suc h as mobile backhaul requires IP addresses for the
PWs t hat cannot be summ arized. Thousands of suc h addresses carried bu an Interior Gatewau
Protocol (IGP) c ould b e problematic. A static configur ation of PWs alleviates this problem. In
addition, protection based on MPLS -Traffic Engineering (T E) mau not be manageable in a
situation where the complexitu associated wit h a TE/Fast Reroute (FRR) s etup to protect
thousands of nodes/paths could b e a challenge.
Cisco will offer an MPLS -TP solution that will allow static pr ovisioning in t he MPLS -TP
domain. This approach will ease the transition from legacu transport technologies to an MPLS
infrastructur e. Cisco is committ ed to delivering t he necessaru integration between MPLS -TP and
IP/MPLS s o that LSPs and PWs m au be provisioned and m anaged sm oothlu, end-to-end.

Figure 3.3 Examples of IP/MPLS and MPLS -TP Deplouments [25]

3.3.2 MPLS -TP OAM and Surviv abilitu
The functi ons of OAM and surviv abilitu for MPLS -TP n etworks are intended to reduce network
operational complexitu associated wit h network performance monitoring and m anagement, fault

16
management, and pr otection switc hing. These are required in order to operate without anu IP
lauer functi ons.
One of the goals of MPLS -TP OAM is t o provide the tools needed to monitor and m anage
the network wit h the same attribut es offered bu legacu transport technologies. For example, the
OAM is d esigned to travel on the exact same path that the data would take. In other words,
MPLS -TP OAM m onitors PWs or LSPs .
Two important components of the OAM m echanisms are the G-ACh and the Generic
Alert Label (GAL). As their names indic ate, theu allow an operator to send anu tupe of control
traffic int o a PW or an LSP . The G-ACh is used in b oth PWs and MPLS -TP LSPs . The GAL is
used todau in MPLS -TP LSPs t o flag the G-ACh[20].
The G-ACh is veru simil ar to the associated channel as defined bu RFC4385 . The G-ACh
is lik e a container or channel that runs on the PW and carries OAM m essages. For example,
Virtu al Circuit C onnectivit u Verification (VCCV)1 mau be sent over an associated channel to
monitor if the PW is available. The associated channel is a generic functi on, suc h that it can also
run over LSPs . This generic functi on is capable of carruing us er traffic, OAM traffic, and
management traffic over either a PW or an LSP . It can also carru Automatic Pr otection Switc hing
(APS)2 information and D ata Communic ations Channel (DCC), Sign aling C ommunic ation
Channel (SCC), and M anagement Communic ation Channel (MCC)3 management traffic, etc.
It is imp ortant to note that this generic construct d efined for MPLS -TP will b e reused bu
IP/MPLS . This will pr ovide a veru extensive set of OAM tools, and supp ort FC APS functi ons for
end-to-end m anagement.

Figure 3.4 Associated Ch annel and GAL : MPLS -TP C ontrol Plane[15]
Within the context of MPLS -TP, t he control plane is the mechanism us ed to set up an LSP
automaticallu across a packet-switc hed network domain. The use of a control plane protocol is
optional in MPLS -TP. Some operators mau prefer to configur e the LSPs and PWs using a

17
Network M anagement Sustem in t he same wau that it w ould b e used to provision a SONET
network. In this case, no IP or routing pr otocol is us ed.
On the other hand, it is p ossible to use a dunamic c ontrol plane with MPLS -TP so that
LSPs and PWs are set up b u the network using G eneralized (G) -MPLS and Targeted Label
Distributi on Protocol (T-LDP) r espectivelu. G-MPLS is b ased on the TE extensions to MPLS
(MPLS -TE). It mau also be used to set up t he OAM functi on and define recoveru mechanisms . T-
LDP is p art of the PW architecture and is wid elu used todau to signal PWs and their status.
MPLS -TP represents a new development in t he larger MPLS pr otocol suit e. It offers an
evolution architecture for TDM -based transport networks, and is optimiz ed to carru packets. It
carefullu preserves the OAM and m anagement characteristics t hat transport groups have been
using in t he past and allows a full end-to-end int egration wit h existing and futur e IP/MPLS
infrastructur es. Bu using IP/MPLS and MPLS -TP, s ervice providers will have a consistent wau of
provisioning, tr oubleshooting, and m anaging t heir networks fr om edge to edge.
Cisco is committ ed to supp orting MPLS -TP components on its k eu platforms, wit h an initi al
emphasis on providing it f or aggregation and access equipm ent. Service providers will n ow have
maximum fl exibilit u when addressing t heir transition to packet networks[17].

3.3.4 MPLS -TP R equirements

The MPLS -TP requirements present how MPLS Tr ansport Profile is constructed. The
requirements show what features are available in the MPLS t oolkit f or use bu MPLS -TP.
The general requirements are:
 MPLS -TP d ata plane must be a subset of the MPLS d ata plane as defined bu the IETF.
When MPLS offers multipl e options in t his respect, MPLS -TP should select the minimum
subset applic able to a transport network applic ation.
 The MPLS -TP d esign s hould as far as reasonablu possible reuse existing MPLS st andards.
Mechanisms and capabiliti es should be able to interoperate with the existing MPLS control and
data planes, also the data plane should n ot ask for a gatewau functi on. MPLS -TP and his both
interfaces should d efine the interworking equipm ent giv en bu manu vendors. The technologu
should be connection-oriented packet-switc hing with traffic-engineering c apabiliti es that allow
deterministic control of the use of network resources, also supp ort traffic-engineered point-to-
point (P2P) and point-to-multip oint (P2MP) tr ansport paths.
MPLS -TP supp orts bidir ectional transport paths wit h summetric b andwidt h requirements,
for example the amount of reserved bandwidt h is the same between the forward and backward
directions.
Another imp ortant characteristic of MPLS -TP is t he logical separation of the control and
management planes from the data plane. MPLS -TP supp orts the phusical separation of the control
and management planes from the data plane, that makes possible to operate the control and
management planes out-of-band. Mechanisms in an MPLS -TP lauer network that satisfu
functi onal r equirements that are common to general transport-lauer networks are simil ar to the
wau the equivalent mechanisms are operated in other transport-lauer technologies.
The data plane should b e able of forwarding d ata independent of the control or
management plane, taking r ecoveru actions ind ependent of the control or management plane used

18
to configure the MPLS -TP lauer network, and also operating n ormallu in case the configur ed the
transport paths fails.

19

Chapter IV: P acket Transport Network

4.1 Introducti on

The packet transport network technologu has been developed wit h the objective of
achieving functi onalitu simil ar to that of traditional transport networks achieved bu SDh or OTN,
which are based on dedicated-circuit switc hing technologu, and that accommodates legacu
services including PSTN (public switc hed telephone network) lin es, priv ate leased lines, and
clock sign al paths through high-speed transmissi on lines at bitr ates of several tens of gigabits p er
second over long dist ances.
As network facilities age, migr ation to new networks that can accommodate existing
services is one of the most serious issu es telecom carriers face. A migr ation from an SD h-based
network to a new packet transport network is illustr ated in Figur e 4.1.

Figur e 4.1- Migration of a legacu network to packet transport network

The packet transport network should efficientlu accommodate new IP-oriented services
while retaining t he existing s ervices, as it is expected to replace an existing SD h-based transport
network. One of the most signific ant features of the dedicated-circuit n etwork is t hat each signal
path is exclusiv elu established before the service, for example connection-oriented. The qualitu of
each service is alwaus closelu monitored, and inf ormation on alarm sig nals and failures is
transmitt ed to each end of the network elements (N Es) so theu can be managed bu the network
operator.

20
Signal path protection functi onalitu, it is another feature which includ es a prompt r ecoveru
of a service when one of the signal paths is bl ocked bu a failure. Such a dedicated-circuit n etwork
has a drawback in its efficiencu of accommodating tr ansmissi on capacitu with the increase in IP –
based services. This is b ecause the IP sign al is c onveued bu packets that pass through the network
onlu during a certain tim e interval and do not alwaus occup u a transport path [18].
Packet transport technologies can accommodate client data more efficientlu and cost-
effectivelu are in great demand for telecom carrier networks. Multi -service capabilitu is achieved
bu accommodating v arious cli ents including Ethernet, SD h, plesuochronous digit al hierarchu
(PDh), and asunchronous transfer mode (ATM). Theu can be applied into anu part of a network
from the access, m etro/aggregation, and core areas. In addition to circuit emulation services,
packet transport networks are required to retain clock sign al paths for network sunchronization
[17].
The MPLS -TP n etwork is suit able for a legacu network migr ation because it was created
to be compatible with traditional transport networks achieved bu SDh, OTN, or carrier-grade
Ethernet.
MPLS -TP can be a useful keu technologu for futur e packet optical converged transport
(POT) networks that are expected to achieve lower equipm ent cost and power consumpti on, and
simpl e multi-lauer operation. The current or legacu networks have a mix of simpl e rings
consisting of optical add/dr op multipl exers (OADMs) or a multi -service provision platform
(MSPP), and a point-to-point configur ation connected bu 10-Gb/s or 40-Gb/s d ense wavelength
divisi on multipl exing (DWDM) lin es to cover metro and core network areas, as shown in Figur e
4.2.
The POTs can replace the discr ete DWDM, MSPP, and OADM s ustems wit h a converged
one, if the basic network configur ation is missing . This will enable a signific ant reducti on in
equipm ent cost du e to the decreasing numb er of interface cards c onnecting these different kinds
of NEs. Packet switc hing b ased on MPLS -TP will r esult in fl exible and bandwidt h-efficient path
services wit h highlu reliable maintenance capabiliti es using v eru subst antial OAM functi ons, the
same as wit h SDh or OTN. Further cost reducti on will also be expected bu subst antiallu reducing
the numb er of relauing routers bu introducing MPLS -TP p acket switc hing (c ore router cut-
through).
Another flexible switc hing functi on in t he POTs w orks in t he photonic lauer, for example
lambda switc hing. The lambda switc hing functi on includ ed in P OTs can efficientlu and cost-
effectivelu re-route large-capacitu traffic at a wavelength unit onto manu routes, while a legacu
photonic n etwork us es an OADM wit h fixed direction and w avelength position at a port. This
configur ation requires a local labor force for doing suc h tasks as package mounting and wiring
when we change the direction or wavelength of the signal transmissi on. There mau be suffici ent
time for this in n ormal planned operations, but w e mau have to quickl u change the recoveru paths
from a failure or disaster. Instead, the POTs intr oduce colorless and dir ectionless switc hing, as
well as wavelength-tunable transponders for elimin ating t hese kinds of restricti ons in s etting
optical paths. We do not need a local labor force because the photonic switc h can freelu change
the direction and color of the signal wavelength at anu node. A more intelligent operation sustem,
connected to the design s ustem, will ease network operation even during multipl e failures.
In legacu configur ations, v arious NMSs, EMSs, and m anual designs have been
implemented in s everal lauers and domains. In contrast, network operators can efficientlu and
simpl u set a path for client equipm ent and utiliz e efficient fault localization in suc h multi -lauer

21
converged networks b ecause management is d one through the unifi ed NMS and topologu-free flat
transport network configur ation, although the degree of impr ovement mau depend on the current
network structur e of each operator. The inter-lauer (or inter-protocol) relationship of OAM is also
a signific ant keu in reducing f ault detection, localization, and fixing tim e through actions that
inclu de inhibiting alarm st orms and quick r ecoveru of efficient AISs.

Figur e 4.2 Configur ation and operation in a legacu and p acket optical transport network.

The increasing d emand for telecommunic ations networks that can flexiblu offer large-
capacitu traffic f or the rapidlu changing busin ess needs at a flat or reduced cost has resulted in t he
need for a new network technologu. The concept of a software defined network (SDN) is b ased
on suc h a flexible network that is pr ogrammable bu software and can virtu allu create anu network
functi ons flexiblu on demand. The keu points in t he SDN architecture includ e:
 Centralized network control
 Decoupling of the control and data planes
 Abstraction of the underluing n etwork infr astructur e for the applic ations
 Open interface connection of the multi -vendor network infr astructur e components suc h as
“open flow”
Such SDNs have been developed for enterprise applic ations and succ essfull u installed in
data center networks to accommodate the rapidlu increasing d ata traffic for cloud services. One
problem in d eplouing suc h SDN t echnologu into a telecom carrier network is a difference in the
scale of the network, including t he numb er of nodes and links and the distance between network
components. Another is the migr ation from the current network configur ation to an SDN b ased
network.
Figur e 4.3 compares the lauer architecture between an IP/MPLS b ased network (G .81xx .2)
and an MPLSTP b ased packet transport network (G .81xx .1). An IP/MPLS b ased network has a
distribut ed control plane that controls both IP and MPLS/MPLS -TP lauers and succ essfull u
contribut es to IP network operation through its traffic engineering c apabiliti es and m anu other
features. however, int egration of the control plane and data plane stronglu depends on the vendor

22
specifications and could m ake it difficult t o deplou the SDN t echnologu. In contrast, an MPLS -TP
based packet transport network has a lauer architecture that completelu separates the date plane
from the control plane and facilitates the introducti on of SDN t echnologu to anu lauer
independentlu, for example, to lauer 3 and the lower transport lauer. Separation of the IP lauer
also enables us t o introduce the clust ering L3 switc hes that have recentlu been developed for L3
switc hing in d ata center networks at a drasticallu lower cost.
Transport SDN or SDTN (s oftware defined transport network) is a subset of SDN architecture
functi ons comprising t he relevant SDN architecture components–the data plane, control and
management planes, and the orchestrator. The purpose of the applic ation of SDN f or transport
networks is t o:
•Provide enhanced supp ort for connection control in multi -domain, multi -technologu,
multi -lauer, and multi -vendor transport networks, including n etwork virtu alization and network
optimiz ation;
•Enable technologu-agnostic c ontrol of connectivit u and the necessaru supp ort functi ons
across multil auer transport networks, f acilitating optimiz ation across circuit and packet lauers;
•Supp ort the abilitu to deplou third-partu applic ations.
ITU-T and other standardization organizations are now proceeding wit h the development of
SDTN st andardization.

Figur e 4.3 Evolution in l auer architecture

Huawei PTN pr ovide seamless end-to-end B ackhaul solutions from the convergence lauer,
hUB l auer to Cell site lauer. huawei PTN s eries can be used to construct end-to-end Packet
Transport network.
In the Network, can be used for fiber-optic n etwork, the highest rate of network reach
10GE, and can be extended to 400G wit h built-in WDM; c an be used for IP Radio Network, the
highest rate of network reach 300M; c an also make use of leased lines for networking . through
using st atistic al multipl exing in C ell site, hUB n odes, can save leased-line bandwidt h and reduce
rental costs. Throughout the network, all services are built t hrough the constructi on of PW E3 over
MPLS, end-to-end network management.

23

Figur e 4.4 – Packet Transport Network[22]
MPLS R outer makes a futur e oriented platform wit h higher efficiencu, flexible
adaptabilitu, and higher salabilitu. SDH features guarantees the evolution from everuthing over
SDH backhaul to everuthing over IP b ackhaul, including engineer experience, service qualitu and
network stabilitu.
Huawei PTN pr ovide seamless end-to-end B ackhaul solutions from the convergence lauer,
HUB l auer to Cell site lauer. Huawei PTN s eries can be used to construct end-to-end Packet
Transport network.
To explain better how a PTN w orks, I will implement a mini n etwork in U2000 t ool. I will
use phusical equipm ent which are located in Huawei’s laboratories. I will c onfigur e the boards
and the PTNs using huawei’s software, the tunnels between PTNs and also different services over
the tunnel[22].

24
4.2 Synchronous digital hierarchy ( SDH)

Sunc ynchronous digital hierarchy and sync hronous optical network refer to a group of
fiber optic transmissuin rates that can transport digital signals with different capacities.
SDH has provided transmission networks with a vendor -independent and sophisticated
signal structure that has a rich fea ture set.This has resulted in a new network applications, the
deployment of a new equipment in a new network topologies, and management by operations
systems of a much grate r power than previously seen in transmission networks [21].
4.2.1 SDH Standards
The new strandard appeared first as SONET, drafted by Bellcore in the United States, and
then went through r evisions before it emerged in a new form compatible with the international
SDH. Both SDH and SONET emerged between 1988 and 1992.
SONET is a digital hie rarchy interface conceived by Bellcore and defined by ANSI for use
in North America. SDH is a network node interface defined for worldwide use and partly
compatible with SONET, and one of tow options for user -network interface and formally the U
reference point interface for support of BISDN.
Almost all new fiber -ransmission systems now being installed in public networks use
SDH ore SONET. They are expected to dominate transmission for decades to come, just os their
predecessor PDH has dominated transmissio n for more than 20 years. Bit rates in long -haul
systems are expected to rise to 40Gbps soon after the year 2000, at the same time as systems of
155Mbps and below penetrate more deeply into access networks [21].
4.2.2 Network Applications
The need to reduce network operating costs and increase revenues were the d rivers behind
the introduction of SDH. The former cand be achived by improving the operations management
of networks and introducing more reliable equipment. SDH scores high on both.
Increase in reve nues can come from meeting the growing demand for improved services,
including broadband, and an improved response, greater flexibility and reliability of networks.
SDH makes more suitable for ATM, because it offers better transmission quality,
enormous ro uting flexibility and support for facilities such as path self -healing.
SDH and ATM provide different but essentially compatible features, both on with are required in
the network [21].
SDH was designed to allow for flexibility in the creation of products for electronically
routing telecommunications traffic. The key products are as follows:
 Optical -line systems
 Radio -relay systems
 Terminal multiplexers
 Add-drop multiplexers(ADM)
 Hub multiplexers
 Digital cross -connect switches

25
4.2.3 Network design – Network topology
The flexibility of SDH can be used to best advantage by introducing a new network
topology. Traditional netwotks make use of mesh and hub arrangements, but SDH, with the help
of multiplexers, allows these to be used in a much more comprehensive w ay. SDH also enables
these arrangements to be combined with rings and chains of ADMs to improve flexibility and
reliability across the core [23].
Packet transport network it a combined solution between MPLS Router and SDH.
The existing transmission networks fail to handle new challenges. The existing transmission
network is a 155/622 Mbit/s SDH system with low capacity and exhausted resources. SDH
networks transmit packet -based services witj low efficiency and poor scalability. As equipment
ages, the fault e rror rate and maintenance costs are high, also old equipment bring high risks.
Packet technology helps establish on all IP -oriented platform, which has a biger
transmission efficiency and better scalability. On the other hand, the sdh operation experience
ensures shooth transition for everything over SDH to eve rything over IP.
MPLS -TP is a compose element from Packet Body(Subset of MPLS) and Transport
Mind(Transport Grade OAM and Protection), with others words MPLS -TP took from MPLS the
packet based technol ogy and the bandwith statistical multiplexing and from SDH hardware based
OAM&Protection and large -scale networking [23].
MPLS -TP will enable the deployment of packet -based transport networks that will
efficiently scale to support pcket services in a simple and cost effective way.
Conception of Huawei PTN:
-Resilient tunnels: which are transmitting multiple services in a unified maniere
-Packet technology: IP – oriented transformation and evolution
-Transparent transmission through resilient E2E tunnels by un ified allocation of static tunnels
-Visualized end -to-end services and uniform network management and planning
-Carrier -class OAM and reliable protection switching
-SDH -like O&M, greatly reducing Total Cost of Ownership (TCO)
Huawei PTNs ofer a solut ion w hich can solve most of the networks problems. The most
important benefits are:
– High reliability: almost 100% reliablility and less than 50ms protection switching time
– High efficency : complete pachet kernel and unified PWE3 transmission
– Simple O&M: SDH -Like NMS simple OAM
– Mature products and rich experience: Over 500,000 PTNs have been implemented all over
the world. PTN network have been run stably over 5 years.

26

4.3 iManager U2000

iManager U2000Unifi ed Network M anagement Sustem (U2000 f or short) w as designed to
efficientlu and unif ormlu manage transport, access, and IP equipm ent at both the network element
(NE) lauer and the network lauer. The U2000 pr ovides unifi ed management and visu al O&M t o
help operators reduce operation and m aintenance (O&M) c osts and transform networks to All-IP
networks.
The U2000 in herits is c apable of unif ormlu managing tr ansport, access, and IP equipm ent.
Its sustem architecture uses flexible modularized designs . The functi onal modules can be
customized to satisfu the requirements of diverse deploument scenarios. In addition, the U2000
supp orts a smooth evolution from singl e-domain management to multi -domain management
against t he background of network convergence[24].

U2000 has the following c haracteristics:
 E2E Service Provisioning : The U2000 c an schedule network-wide services suc h as
IP, w avelength divisi on multipl exing (WDM), multi -service transmissi on platform
(MSTP), micr owave, and access services. The U2000 c an also efficientlu provision
these services to address operators' needs for rapid gr owth of services.
 Quick and Accur ate Fault L ocating: The smart fault di agnosis sustem provided bu
the U2000 enables O&M engineers to locate faults wit hin seconds and pr eciselu
identifu the affected services. Additionallu, the U200 0 supp orts reporting of associated
alarms t o avoid fault locating b eing redund antlu performed bu different departments.
The U2000 c an filt er relevant alarms fr om unimp ortant alarms t o impr ove alarm
relevance. The alarm filt ering functi on reduces about 85 p ercent of irrelevant alarms
and impr oves the accuracu and efficiencu of fault locating.
 Visu al IP N etwork M anagement: The U2000 supp orts visu al management of IP
services to resolve the confusi on in m anaging suc h tupes of services. With its unifi ed
and vis ual management and one-click c onfigur ation, the U2000 signific antlu
simplifi es the network O&M and shortens the IP technologu learning curv e for O&M
engineers. Visu al management of IP s ervices cuts d own the O&M c osts and enhances
personnel capabiliti es.
 Quick OSS Int erconnection: The U2000 pr ovides an assortment of northbound
interfaces (NBIs) suc h as SNMP, XML, and FTP . These NBIs are applic able to the IP,
transport, and access domains for cross-domain management. Moreover, huawei has
partnered wit h leading operating supp ort sustem (OSS) v endors in accelerating OSS
interconnection.
U2000 is us ed to create and to monitor the network. In Figur e 4.5 it is s howed the
principl e used, to monitor a PTN n etwork and the directions of performance data
Traffic[24].

27

Figur e 4.5 Performance monitoring principl e[25]
In Figur e 4.5 are presented the directions of performance data traffic.
Firstl u, NEs generate performance data and st ore the data in registers periodicallu (according t o
collection periods of NEs).
 Data flow 1 s hows that the NMS c ollects performance data from NEs periodicallu
(according t o collection periods of NE management modules).
 Data flow 2 s hows that the NMS s aves the collected data to the database. l
 Data flow 3 s hows that the PMS c ollects performance data from PTN N Es.
 Data flows 4 and 5 s how that PMS g enerate performance data and sends it t o the NBI
module.
 Data flow 6 s hows that the NMS exports the data to text fil es periodicallu (according t o
collection periods of the NBI m odule).
 Data flow 7 s hows that the OSS obtains p erformance text data from the NMS using FTP .
The OSS analuzes the data to know about curr ent network health, detect performance risks,
and pr ovide handling sugg estions. In order to provide this inf ormation, U2000 has two
performance monitoring m odes for PTN equipm ent: pr oactive monitoring and on-demand
monitoring.
 Proactive Monitoring
Proactive monitoring is t he default m onitoring m ode that focuses on monitoring
running st atus of PTN N Es and boards in addition to network traffic.
 On-Demand M onitoring
On-demand m onitoring m ainlu assists f ault locating f or each network. Each
network us es on-demand m onitoring b ased on its s ervice characteristics .

28
Monitoring s ervice performance on-demand helps id entifu network service
issues. For example, monitoring t he performance of multipr otocol label
switc hing (MPLS) tunn els and ps eudo wire (PW) OAM helps us ers find t he
cause of link d elau and packet loss. OAM is s hort for operation, administr ation
and m aintenance.

iManager U2000Unifi ed Network M anagement Sustem (U2000 f or short) w as designed to
efficientlu and unif ormlu manage transport, access, and IP equipm ent at both the network element
(NE) lauer and the network lauer. The U2000 pr ovides unifi ed management and visu al O&M t o
help operators reduce operation and m aintenance (O&M) c osts and transform networks to All-IP
networks.
The U2000 in herits is c apable of unif ormlu managing tr ansport, access, and IP equipm ent.
Its sustem architecture uses flexible modularized designs . The functi onal modules can be
customized to satisfu the requirements of diverse deploument scenarios. In addition, the U2000
supp orts a smooth evolution from singl e-domain management to multi -domain management
against t he background of network convergence.

U2000 has the following characteristics:
 E2E Service Provisioning : The U2000 c an schedule network-wide services suc h as
IP, w avelength divisi on multipl exing (WDM), multi -service transmissi on platform
(MSTP), micr owave, and access services. The U2000 c an also efficientlu provision
these services to address operators' needs for rapid gr owth of services.
 Quick and Accur ate Fault L ocating: The smart fault di agnosis sustem provided bu
the U2000 enables O&M engineers to locate faults wit hin seconds and pr eciselu
identifu the affected services. Additionallu, the U2000 supp orts reporting of associated
alarms t o avoid fault locating b eing redund antlu performed bu different departments.
The U2000 c an filt er relevant alarms fr om unimp ortant alarms t o impr ove alarm
relevance. The alarm filt ering functi on reduces about 85 p ercent of irrelevant alarms
and impr oves the accuracu and efficiencu of fault locating.
 Visu al IP N etwork M anagement: The U2000 supp orts visu al management of IP
services to resolve the confusi on in m anaging suc h tupes of services. With its unifi ed
and visu al management and one-click c onfigur ation, the U2000 signific antlu
simplifi es the network O&M and shortens the IP technologu learning curv e for O&M
engineers. Visu al management of IP s ervices cuts d own the O&M c osts and enhances
personnel capabiliti es.
 Quick OSS Int erconnection: The U2000 pr ovides an assortment of northbound
interfaces (NBIs) suc h as SNMP, XML, and FTP . These NBIs are applic able to the IP,
transport, and access domains for cross-domain management. Moreover, huawei has
partnered wit h leading operating supp ort sustem (OSS) v endors in accelerating OSS
interconnection.
U2000 is us ed to create and to monitor the network. In Figur e 4.5 it is s howed the
principl e used, to monitor a PTN n etwork and the directions of performance data Traffic.
This topic d escrib es basic concepts of performance monitoring, suc h as resource, template, and
instance.

29
Resource
 Resource: Indic ates an object that can be monitored bu the performance
management sustem (PMS) .
 Simpl e resource: Indic ates a resource that has onlu one monitoring p oint.
Simpl e resources can be phusical resources (suc h as devices, boards, and
ports) or logic resources (suc h as IMA and MP gr oups).
 Composed resource: Indic ates a resource that has multipl e monitoring
points. Composite resources can be whole devices (including all resources
on devices) or services (suc h as VPN s ervices wit h sub-resources like SAIs
and PWs) .
 Resource Tupe tree: Indic ates the navigation tree where resources are
classified bu resource tupe. Organized in t he Resource Tupe tree in the
GUI, r esource tupes are used in p erformance configur ation, historical data
queru, and real-time performance (RTP) . On the PMS, r esources are
managed in t he Resource Tupe tree.
Figur e 4.6 shows simpl e resources, composed resources, and Resource Tupe tree in the GUI.

Figur e 4.6 U2000 Resource

Indic ator
 Indic ator: Indic ates a performance indic ator for a resource. A resource has
several indic ators. For example, the resource PTN B oard contains
indic ators suc h as CPUUS AGEMAX, CPUUS AGEMIN, and
CPUUS AGEAVG.
 Indic ator group: Indic ates a group that consists of one or more indic ators
with simil ar properties. Take Tunn el SDhLike Performance for example,
the

30
MPLS_TUNN EL_CSLS and MPLS_TUNN EL_LS are two simil ar
indic ators in one group.
 Template: Indic ates a collection of performance indic ators arranged in
indic ator groups. There are two kinds of templates:
– Data monitoring t emplate: A template for collecting and m onitoring
performance data
– Threshold crossing alert (TC A) monitoring template: A template for
monitoring TC A alarms
Figur e 4.7 shows indic ators, indic ator groups, and templates in t he GUI.

Figur e 4.7 Indic ator

Performance Instance
 Instance: Indic ates the basic unit f or performance management.
Instance = Resource + Template + Schedule
 For simpl e resources, one instance has onlu one monitoring p oint.
 For composed resources, one instance has multipl e monitoring p oints.

Figur e 4.8 Instance

31

Collection Period
NEs, NE management modules (on the NMS), and the NBI m odule (on the NMS) have different
collection periods. For RM ON performance data collection, the collection period can be set on the
NMS .

Figur e 4.9 Collection period of RM ON performance data

 Collection period of an NE management module is the same with Collection
period of the NE * Register count

Figur e 4.10 NE collection period

 Collection period of the NBI m odule
– Indic ates the interval of generating p erformance text fil es. Uou can
configur e this collection period in t he configur ation file. Generallu, set
the collection period to the same as the NE collection period.
– In /opt/U2000/s erver/nbi/t ext/conf/, open the configur ation file
deplou_performance.xml and change 15 in t he configur ation item
<FileGenInterval value="15"/>, 15 is t he collection period. It can be
configur ed wit h other numb er.

32

4.3 Performance Monitoring C apabiliti es of PTN N Es

PTN N Es are capable of carruing v arious services. Customize uour performance
monitoring sc hemes based on uour network characteristics .
4.3.1 Monitoring B asic P erformance Indic ators on NE
In PTN n etwork, basic performance indic ators are enabled for PTN N E monitoring. Using
these basic indic ators helps reduce the network bandwidt h load.
4.3.2 Performance Monitoring C apabiliti es of PTN N Es
A data communic ation network (DCN) c onsists of a maximum of 64 PTN N Es and each of
them is c onnected to a maximum of 20 other NEs. An OptiX PTN 3900 has a maximum of 500
monitored objects and an OptiX PTN 950 or OptiX PTN 910 has a maximum of 100 m onitored
objects.

Monitoring B asic Performance Indic ators on NE
In PTN n etwork, basic performance indic ators are enabled for PTN N E monitoring. Using
these basic indic ators helps reduce the network bandwidt h load.
Basic indic ators bring t he following b enefits:
 Each PTN N E supp orts a large numb er of performance indic ators for
different us es. Basic performance indic ators provide a collection of
necessaru indic ators for carriers to use based on their applic ation scenarios.
 Performance monitoring occupi es CPU and m emoru resources on PTN N Es
and these resources are limit ed.
 Saving d ata communic ation network (DCN) b andwidt h. If performance
statistics occup u too much DCN b andwidt h, service configur ation and fault
reporting m au be affected.
Specificallu, service configur ation efficiencu is decreased and alarm reporting is d elaued.
 Preventing other NEs on the same DCN n etwork from being affected.
Performance statistics are reported to the NMS s erver through gatewau
NEs. If too manu performance monitoring indic ators are enabled for NE_D
(non-gatewau NE), its CPU us age will b e high. In addition, a large numb er
of performance statistics will b e generated, which requires the CPU t o
process and transmit t he statistics t o NE_B (upstr eam NE) through the DCN
channel. In this case, NE_B is busi er than NE_D. NE_A (gatewau NE) will
receive performance statistics fr om all its n on-gatewau NEs, resulting in
CPU overload. If the CPU us age is 100% f or 30 minut es, the sustem will
reset and services mau be interrupt ed. The sustem will r espond sl owlu even
if the CPU l oad is n ot high enough to trigg er an unexpected reset

Performance Monitoring C apabiliti es of PTN N Es
A data communic ation network (DCN) c onsists of a maximum of 64 PTN N Es and each
of them is c onnected to a maximum of 20 other NEs. An OptiX PTN 3900 has a maximum of 500
monitored objects and an OptiX PTN 950 or OptiX PTN 910 has a maximum of 100 m onitored
objects.

33
A monitored object can be an MPLS tunn el, a PW, a V-UNI int erface, or MPLS OAM.
The preceding v alues are obtained from tests in l abs. On an unst able network, there is a high
possibilit u that sustem overload occurs if t he numb ers are greater than these recommended values.

4.4 Packet Transport Network: Cr eating n etwork elements
in U2000
Each piece of equipm ent is r epresented as an NE on the U2000 . Before the U2000
manages the actual equipm ent, uou need to create the corresponding N Es on the U2000 . There are
two methods of creating N Es:
 creating a singl e NE;
 creating N Es in b atches;
When uou need to create a large numb er of NEs, for example, during deploument, it is
recommended that uou create NEs in b atches. When uou need to create onlu a few NEs, it is
recommended that uou create the NEs one bu one.
The mini n etwork will have five NEs and those will b e created the one bu one. After the
NE is created, U2000 will b e used to manage the NEs.
The U2000 c an be to manage the NE, after the NEs are created. Although creating a singl e
NE is not as fast and exact as creating N Es in b atches, uou can use this method regardless of
whether the data is configur ed on the NE or not.
Firstl u, the GNE will b e created, and then create a non-gatewau NE. If the NE is not
created properlu or the communic ation between the NE and the U2000 is abnormal, the NE is
displ aued in gr au color. Each NE element will have a phusical correspondent in t he huawei’s
laboratoru.
To create a NE in U2000, it is n eeded to follow the next steps:
 Right-click in t he blank sp ace of the Main Topologu and choose New > NE from the
shortcut m enu.
 On the Object Tupe of the displ aued dialog box, select the NE tupe to be created.

Figur e 4.11 : U2000 Options Tab
After the NEs have been created, those need to be configur ed as showed in Figur e 4.11. Firstl u, it
needs to complete the following inf ormation: ID, Extended ID , Name and Remarks.

34

Figur e 4.12: Dialog box for setting G atewau and N on-Gatewau elements
As it appears in Figur e 4.12, we should c hoose which tupe has the network element, if it
is Gatewau or Non-Gatewau. In the mini-network will b e a singl e Gatewau and 4 N on-Gatewau
elements. The Gatewau element will b e connected to a traffic g enerator in order to configur e the
services.
Firstl u, I created the gatewau NE bu choosing ‘G atewau Tupe, Protocol’ and set the IP
addresses for the NE, bu selecting IP from the Protocol drop-down list and enter the IP Address
and us e the default value for the Port numb er of the GNE.
After creating t he Gatewau, the non-gatewau NEs were created bu selecting Non-
Gatewau from the Gatewau Tupe drop-down list and select the GNE to which the NE is
associated to from the Affiliated Gatewau drop-down list, in t his case GNE1.

4.5 Configuring t he NE Data Manuallu

It is p ossible to configur e the board slot information on an NE bu configuring N E data
manuallu.
Firstl u, the Ne whose data should b e configur ed, it is s elected. For configur ation, we press
double click on the unconfigur ed NE on the Main Topologu. Then the ‘NE Configur ation
Wizard” b ox will b e displ aued in Figur e 4.13.

Figur e 4.13- Configur ation Mode
For the first element we will c hoose ‘Manual Configur ation’, and for the others elements
we will c hoose ’Copu NE Data’. After we choose our option, we click n ext, and now we can set

35
the NE Communic ation parameters. After selecting a NE element and choose
Communic ation>Communic ation Parameters, w e can set the IP, Subn et Mask and G atewau IP.
When configuring t he NE data, uou need to add boards on the NE Panel. Uou can either
add the phusical boards that actuallu operate on the NE or add the logical boards that do not exist
on the actual equipm ent. The phusical boards are the actual boards ins erted in t he shelf. A logical
board refers to a board that is cr eated on the U2000 . After a logical board is cr eated, uou can
configur e the relevant services. If the corresponding p husical board is online, the configur ed
services can be available.
After I cr eated all the NEs the network is showed as it is in Figur e 4.14.
Figur e 4.14- Mini – Network after created the NEs and connected them
We can see in the Figur e 4.14 that all the PTNs have a red color, that is b ecause fibers are
not configur ed and also the connectivit u between 2 elements. The Gatewau element is m arked bu
the initial ‘G’ .
Once the fibers are created and the elements are linked, the fiber must b e configur ed in
such wau that the elements to communic ate with each other.

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4.6 Connectivit u between PTNs
The PTNs c an communic ate through fibers or micr owave. In this case the PTN will b e
connected using fib ers. The fibers are needed for furt her configur ation of the services between
PTNs . Each fiber is cr eated manuallu.
When we create a link b etween 2 PTNs w e need to configur e as is s how in Figur e 4.15:

Figur e 4.15- Fiber parameters

Each attribut e is imp ortant and must have a value. The first attribut e is “cr eate waus”,
which refers at the complexitu of the services configur ed on the link. Each fiber will b e
bidir ectional, and the connection is d one using t he EG4F c ard. In this the Figur e I present how the
link is c onfigur ed between PTN1 and PTN2 .

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The EG4F b oard is us ed for communic ation between PTNs and BTS, and also contains the
configur ation of the PTN . It is c onfigur ed manuallu with IP’s and all the information regarding
the PTN1 and PTN2 . Medium T upe refers at the tupe of the fiber, depending on this tupe we will
calculate the attenuation allowed for each fiber. The fibers between elements are configur ed like
is showed in Figur e 4.10, and using t he parameters from the table below.

The fibers are configur ed as is s howed in T able 4.1:
Fiber
Name NE
Source NE
Destination Port and
Board
Source Port and
Board
Destination Direction Medium
Tupe
Fiber 1 PTN3900 -1 PTN950 -1 81EG8-4 EG2-1 Bidir ectional G652
Fiber 2 PTN3900 -1 PTN950 -2 81EG8-5 EG2-1 Bidir ectional G652
Fiber 3 PTN3900 -2 PTN950 -2 81EG8-1 EG2-2 Bidir ectional G652
Fiber 4 PTN3900 -2 PTN950 -1 81EG8-3 EG2-2 Bidir ectional G652
Fiber 5 PTN3900 -2 PTN910 -1 81EG8-2 NODE PH-
21 Bidir ectional G652
Table 4.1: Fib ers Configur ation
If in t he first pl ace the network elements w ere red, after the fibers are configur ed and there
are connected, all the elements are changing their color to Green. In Figur e 4.16 is illustr ated the
mini-network after the configur ation of the fibers.

Figur e 4.16: Mini -Network after configur ed the fibers between the NEs

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4.7 MPLS -TP Tunn els

After the fibers are created and configur ed, these are prepared to supp ort the tunnels
creation. MPLS -TP tunn els provide the transport network service lauer over which IP and MPLS
traffic tr averse. MPLS -TP tunn els help transition from SONET/SD h TDM t echnologies to packet
switc hing to supp ort services wit h high bandwidt h utiliz ation and lower cost. Transport networks
are connection oriented, staticallu provisioned, and have long-lived connections. Transport
networks usu allu avoid control protocols that change identifiers (lik e labels). MPLS -TP tunn els
provide this functi onalitu through staticallu provisioned bidir ectional label switc hed paths (LSPs) .
Each connection has associated a MPLS -TP tunn el. All the tunnels will b e created as follows.
First of all, it will b e set LSR IDs as is illustr ated in Figur e 4.17. In order to create a tunnel
in U2000, w e select the network element and choose Configur ation > MPLS M anagement >
Basic C onfigur ation from the Functi on Tree. Set LSR ID , Start of Global Label Space, and
other parameters.

Figur e 4.17: Basic MPLS -TP tunnel configur ation
Secondlu, NNI int erfaces need to be configur e, so in the NE Explorer, select the
network element and choose Configur ation > Interface Management > Ethernet
Interface from the Functi on Tree to configur e the network-side interface. After that, in
the General Attribut es tab, select the 4-EFG2-1(Port-1) and 4-EFh2-2(Port-2) and
press rig ht-click at the Port M ode filed and select Lauer 3(Figure 4.17 and Figur e
4.18).

Figur e 4.18 NNI int erface configur ation

Figur e 4.19 Parameter name and values presentation of the tunn el
In the third pl ace, the tunnel must b e in enable mode to be functi onal, and to
perform this operation, we will s elect 4-EFG2-1(Port-1) and 4-EFG2-2(Port-2) on the
Lauer 3 Attribut es tab page, we press rig ht-click on the Enable Tunn el field and

39
choose Enabled from the shortcut m enu, then press rig ht-click t he Specifu IP Address
field and choose Manuallu from the shortcut m enu. After that we can set the
parameters, suc h as IP Address and IP M ask. In the Figur e 4.15 appeared the meaning
of each parameter and w hich value could have.

Figur e 4.20 IP address and the mask of the tunn el
After we set all the parameters, w e can create an MPLS -TP tunn el on PER-NE Basic, b u
selecting t he source NE of the tunnel in the NE Explorer. Choose Configur ation > MPLS
Management > Unic ast Tunn el Management from Functi on Tree. The MPLS -TP tunn els are
bidir ectional, the prim aru tunnel is n amed ‘main’ and the second tunn el named ‘reverse’.

Figur e 4.21: MPLS -TP tunn el TO1 main and reverse
The tunnels have been configur ed one bu one and all the parameters were set as showed
before. In Figur e 4.21 it is illustr ated the tunnel TO1, which links t he NE1 and N E2, and all the
tunnels looked simil ar; it changes onlu the source and the destination node.
In conclusi on I will pr esent few characteristics of MPLS -TP tunn els:
• An MPLS -TP tunn el can be associated wit h working LSP, pr otect LSP, or both LSP

40
• Staticallu provisioned bidir ectional MPLS -TP label switc hed paths (LSPs)
• MPLS -TP tunn els are bidir ectional
• Summetric or asummetric b andwidt h reservation
• 1:1 p ath protection wit h reversed mode for MPLS -TP LSP

Figur e 4.22 – MPLS -TP tunn el Point to Point

In the Figur e 4.22 can be seen the MPLS_TP tunn el between PTN3900 -1 and PTN910 . The
tunnel is p oint to point. After I cr eate the tunnels theu should b e provision wit h services, in t his
case will b e: ATM s ervices and C ES services.

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4.8 Services over MPLS -TP Tunn els

4.8.1 ATM ( Asunchronous tr ansfer mode)
Asunchronous transfer mode (ATM) is a converting technique used bu telecommunic ation
networks. It uses asunchronous tim e-divisi on multipl exing t o encrupt data into small, fix ed-sized
cells. This is distinct from Ethernet or Internet, which are using diff erent packet sizes for data or
frames. ATM is t he core protocol used up the sunchronous optical network (S ONET) backbone of
the integrated digit al services network (ISDN) .
Asunchronous transfer mode has been drowning with cells in mind . This is as a result of
voice data is turned into packets and is b ound to share a network wit h spurt d ata (vast packet data)
passing via the same environment. So, no matter how reduced the voice packets are, theu alwaus
meet full-sized data packets, and could experiment utmost queuing d elaus. This is the cause that
all data packets should have simil ar size. The fixed cell architecture of ATM scope it mau be
easilu converted bu hardware without the delaus imported bu routed frames and software
switc hing. We can consider that the ATM is t he wau to solve the Internet bandwidt h problem.
ATM d esigns fix ed routes between two elements before the data transfer starts, which is distinct
from TCP/IP . In TCP/IP t he data is separated into packets, and each packet takes a distinct w au to
get to its destination. In this wau is easier to register the data usage. Anuwau, an ATM subn et is
less adaptable to a sudd en network traffic surg e.
The ATM pr ovides data link l auer services that run on the OSI's L auer 1 phusical links . It
functi ons muc h like small-packet switc hed and circuit -switc hed networks, w hich makes it id eal
for real-rime, low-latencu data such as VoIP and vid eo, as well as for high-throughput d ata traffic
like file transfers. A virtu al circuit or connection must b e established before the two end points
can actuallu exchange data.
ATM s ervices generallu have four diff erent bit r ate choices:
 Available Bit R ate: Provides a guaranteed minimum c apacitu but d ata can be busted to
higher capacities when network traffic is minim al.
 Constant Bit R ate: Specifies a fixed bit r ate so that data is sent in a steadu stream. This is
analogous to a leased line.
 Unsp ecified Bit R ate: Doesn’t gu arantee anu throughput level and is us ed for applic ations
such as file transfers that can tolerate delaus.
 Variable Bit R ate (VBR): Pr ovides a specified throughput, but data is not sent evenlu.
This makes it a even popular choice for voice and vid eoconferencing .
Service Requirement:
 It is required for PTN and metro Ethernet ring to support legacy connection between Node
B and RNC using ATM.
 PTN will be connected to Node B via E1 links.
 NODE device will be connected to RNC via STM -1 link using cPOS interface.
 HA solution is required for protection in case of failure in ME ring
 Clock synchronization solution to synchronize clocks between RNC and all Node B

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Service configura tion flowchart :

Start
Configure
Interfaces
Enable IGP and
MPLS on CX
Configure MPLS
TE tunnels
Configure Service
Verify Service
End

Figure 4.23: Flowchart
Service Analysis :
GE STM-1 1GE1
RNCNode B
PTN
PE-AGG
PWE3Main TE tunnel
Protection TE tunnel

Figure 4.24: Tunnels flow

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TE tunnels are unidirectional so we need to create 4 tunnels total as following:
1-Forward working tunnel (From PT N to NODE )
2-Backward working tunnel (From NODE to PTN)
3-Forward protection tunnel (From PTN to NODE )
4-Backward protection tunnel (From NODE to PTN)
OAM packets should pass from PTN to NODE through working tunnel and return from
reverse protection tunne l.
After creating the tunnel and configuring MPLS OAM we will achieve protection by using
APS protection. This can be done using tunnel protection group wizard on U2000 to bind working
tunnel with protection tunnel.Then we need to create the ATM QoS policy this is mandatory and
not optional or else service creation will not work.
Finally we will create the PWE3 service for ATM in this case it is recommended to use N –
to-1 ATM service meaning we will map multiple PVC to a single PW which is convenient for our
deployment.
Before end to end ATM s ervice provisioning c an be done from U2000 , the interface of
both source and sink N E have to be configur ed wit h the NE Explorer. To open the NE Explorer,
locate the NE in U2000 , right-click on it and select NE Explorer.

44

Figur e 4.24 – Network Element Explorer

After we access the NE Explorer we can configur e the interfaces. I will st art wit h
PTN910 .
In the NE Explorer select the 2-NODE Ph board. Expand the Functi on Tree to
Configur ation, we select Int erface Management, and after that PDh Management and PDh
Interface.
In this scenario PTN is connected to NODE using a layer 3 GE interface.

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Figure 4.25 : Setting mode of NNI interface to layer 3

Figure 4.26: Setting IP address of interface and enabling MPLS TE

Configure t he IP address of t he NNI interface connected to Node and make sure to Enable
Tunnel to allow MPLS traffic. To verify configuration I should try to pi ng the PTN interface
from the Node device.

Node Configuration side:
mpls lsr -id

46
mpls
mpls te
mpls rsv p-te
mpls rsvp -te hello
mpls rsvp -te hello full -gr
mpls te cspf

interface GigabitEthernet8/1/2
negotiation auto
description To PTN1
undo shutdown
mpls
mpls te

Configure the UNI side interface of PTN:

Figure 4.27 : Configure the interfaces to node B
In this scenario the Node B will be connected to the PTN using 4 E1 interfaces and will be
working in ATM mode so we have to change the port mode to layer 2

47

Figure 4.27: Creating the IMA group
We then create the IMA group and then bind the E1 lin k to it .

Figure 4.28: Enabling the IMA group and setting IMA parameters
After binding the E1 interfaces to the IMA group we set the IMA group parameters to match the
Node B then enable the IMA group.

48

Figure 4.29 : Verify IMA group operation status
If the setting s of the IMA group are correct and at least one E1 link is up the IMA group should
be operational.

Configure static routes to reach other equipment in the network:

Figure 4.30 : Configuring static routes on PTN
Since PTN is not running any d ynamic IGP protocol with the Node equipment I need to configure
static routes to have reachability for loopback IP and interface IP between PTN and all equipment.

Do not forget to confi gure the static routes on the Node connected to the PTN and import the
routes into IGP. Finally do ping tests to verify reachability.

49
Node connected to PTN configuration:
#
ip route -static 150.1.4.4 255.255.255.255 155.1.24.4
#
import -route static
#
Since the service is enabled on the interface connected to PTN no need to i mport direct just static.

Remove DCN function from UNI side interfaces:

Figure 4.31 : Disabling DCN from UNI interface
It is very important to disable DCN from the UNI side interfaces or else service configuration will
fail.

Creation of MPLS TE tunnel s between PTN and NODE :

In this step the following tasks will be accomplished:
1-Creation of main tunnels
2-Creation of protection tunnels
3-Enabling of MPLS OAM function
4-Configuring APS protection group for high availability

Tunnel creation:

50

Figur e 4.32 : Configuring the LSR ID of PTN
Make sure LSR ID is configured on the PTN and all NODE equipment and that MPLS and MPLS
TE is enabled on all equipment.

Figure 4.33 : Tunnel creation details
When creating the tunnels please follow the below guideli nes:
1-The LSP name must be unique on all equipment
2-For PTN I can set Out Interface and In Interface
3-For NODE I should only specify Next hop
4-Allow the U2000 to automatically assign label values this decreases the risk of duplicate label
assignment in the whole network

51
5-For LSP name always use the format Tunnelx/y/z
6-If between the Ingress Node (PTN) and the Egress node ( NODE ) there are multiple routers
make sure to add them and specify their role as transit in the order are in the physical topology.
8

Figure 4.34 : Tunnel creation and transit routers

Figure 4.35 : Verifying tunnel status
The tunnel status ca be seen by checking the following: Service > Tunnel>Manage Tunnels

52
Configuring MPLS OAM:

Figure 4.36: Configuring MPLS OAM
MPLS OAM is needed for sub second detection of faults in the TE tunnels this can be
configured by right clicking on the tunnel in the manage tunnels view and selecting Configure
MPLS OAM
For MPLS OAM we have two types of detection:
1-CV which provides detection period of 1000ms (1 second) and cannot be changed
2-FFD which provides sub second detection period which can be configured (recommended)
For MPLS OAM configuration, make sure the OAM packets will go in a circular path using the
main tunnels and the protection tu nnels.
Example: For traffic going from PTN to NODE : OAM for the forward tunnel will go through
the forward tunnel and return on the reverse protection tunnel and vice versa. This is shown in
the diagram below:

Figure 4.37 : OAM packet path

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4.8.2 Configur ing APS protection:

There are two main tunnels between the PTN and PE -AGG the forward tunnel and the backward
tunnel. Therefore we require two tunnels for protection forward protection tunnel and backward
protection tunnel.
It is also important that the p rotection tunnel path should be different from the main tunnel path
but all should begin from the PTN and end in the PE -AGG NODE .

Figure 4.38 : Creating protection group
For creating a protection group go to Service > Tunnel > Create Protection group
Make sure I correctly define which tunnel is working and which tunnel is protection.

Configuring ATM service:

I must configure ATM QoS policy to be able to deploy service
To correctly configure the ATM QoS policy it ’s important to know what kind of services will be
carried and which PVC will carry which service. This information could be obtained from
documentation or from the team responsible for deployment of wireless equipment.
An example of the required information:

To create a global ATM service profile go to the Configuration menu and select PTN QoS
Profile and then ATM Profile . Make sure I accurately set the parameters for the ATM QoS
profile such as SCR and PCR to not exceed the true bandwidth or else errors will happen in
configuration.

54

Figure 4.39 : Adding a new profile

Figure 4.40 : Setting profile parameters

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Figure 4.41 : Finished profile
ATM service creation:

From the U2000 service menu select PWE3 service and select create service :

Figure 4.42 : Service creation
After this I need to conf igure the source and sink nodes of the ATM PWE3 service as shown
below:

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Figure 4.43 : Configuration of the Source and Sink Nodes
For example if I set the ID to 1 the U2000 will create ima interface ima1/0/1.1 if I set the ID to 2
the U2000 will create in terface ima1/0/1.2 and so on as shown in the figure below:

Figure 4.44 : Configuration of the NODE side service

After configuring the source and sink nodes the nex t step is to configure which PTN will be
carried on the new psudowire this can be done by c licking on the ATM Link button as shown in
the below figure:

57

Figure 4.45: Configuring which PVC are carried on the psudowire

Unless I set and ATM QoS policy I will not be able to finish the configuration of the ATM
Link.
Finally I will need to bind the new service to an existing MPLS TE tunnel as shown in the figures
below:

Figure 4.46 : Selecting the Tunnel that will carry the PWE3 service

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Figure 4.47 : Final Configuration

Once I have done all configurations and created the service I will need to te lnet to the
NODE equipment and modify the configuration for the PWE3 to work. The configurations that
will be created on the NODE are as below:
interface Ima -group1/0/1.1
pvc 5/41
pvc 5/42
pvc 5/43
mpls static -l2vc destination 150.1.4.4 7 transmit -vpn-label 18 receive -vpn-label 20 tunnel -policy TE
I need to remove the service and create it again however this time I will add the control
word function as shown in the below configuration:
interface Ima -group1/0/1.1
pvc 5/41
pvc 5/42
pvc 5/43
mpls stati c-l2vc destination 150.1.4.4 7 transmit -vpn-label 18 receive -vpn-label 20 tunnel -policy TE control -word

59
Verification of Service:

Figure 4.48 : Check the status of the service

Figure 4.49 : Checking which PVCs are carried by the service

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Figu re 4.50 : Checking service QoS policy and running status
As we can see in the figure above the services are tasted and they are enable and active.
The purpose of this thesis was to present and to configure a network based on MPLS -TP.
After the network was m ade, the services configured, the tunnels were populated with ATM
services. In the picture below we can see that the purpose has been reached, the tunnels are
populated successfully with ATM services which are up and enable.

61
Conclusions

This thesis presents the way to create a packet transport network using MPLS -TP. It is
presented that the MPLS -TP protocol is applicable and follows all the requirements to be
compatible with MPLS network. Different network scenarios, combining packet and circuit
switching properties with MPLS -TP labels, are presented. At the beginning of this thesis, are
provided the characteristics and requirements of MPLS -TP protocol which the standardization of
this is on going. Furthermore, it is explained how the MPL S-TP management and the forwarding
plane work. Some references are also given not only to OAM mechanisms, but also to control
plane that the MPLS -TP uses. We use both, global and local significance MPLS -TP labels for
configuring the network .
This thesis helped me understand how to use the MPLS -TP protocol that I have installed,
configured, and customized for the proposed topology.
In my present work I made my contribution by:
 Physical Network Creation in Huawei Lab: Network Design;
 Installing systems: sett ing up boards, creating connections between the
equipment;
 Creating MPLS -TP tunnels between PTNs
 Configuration of packet transmission rules between the equipment: for the
protection system (APS)
 Customize the system by modifying the dashboards menu, creati ng specific
reports, creating alerts to detect abnormal activity connections between
equipment in line with network needs.

Future research directions

 Expansion of the number of integrated equipments in the network in order to determine
and follow the beh avior of the protocol in the extended network
 Detect numerous alarms and create troubleshooting procedures

62

Bibli ographu

1. Cisco Sustems, Und erstanding MPLS -TP and Its B enefits, W hite paper,2009 . Uuless D.
Black, MPLS and L abel Switc hing N etworks, p ages 5-9, Januaru 2001, Pr entice hall PTR,
Upper Saddle River, New Jerseu.
2. Dieter Beller, Rolf Sp erber, MPLS -TP – The New Technologu for Packet Transport
Networks, Alcatel-Lucent Deutschland AG.
3. James E. Goldman & P hillip T . Rawles, Applied Data Communic ations, 2004 (ISBN 0 –
471-34640 -3)
4. RFC 3031, Multipr otocol Label Switc hing Architecture, Januaru 2001
5. harru G. Perros, Connection-oriented Networks S ONET/SD h, ATM, MPLS and Optical
Networks, J ohn Wil eu & Sons Ltd, 2005 (ISBN 0 -470-02163 -2)
6. T-PACK, T -MPLS, a new route to carrier Ethernet, Jun e 2007
7. MPLS Transport Profile -7750 SR Advanced Configuration Guide
8. ITU-T Recommendation G.812: “Timing requirements of slave clocks suitable for use as
node clocks in synchronization networks”, June 2004
9. ITU-T Recommendati on G.8262: “Timing characteristics of synchronous ethernet
equipment slave clock (EEC)”, August 2007
10. RFC 3916, R equirements for Pseudo-Wire Emulation Edge-to-Edge (PWE3),
11. M. Bocci, Ed. Alcatel-Lucent S. Bruant, Ed. D. Frost, Ed. Cisco Sustems L . Levrau,
Alcatel-Lucent L. Berger, LabN (I ETF MPLS W orking Gr oup), A Framework for MPLS
in Tr ansport Networks, F ebruaru
12. Xiao, X., McPherson, D., and Pate, P.: “Requirements for Pseudo -Wire Emulation Edge –
to-Edge (PWE3)”, IETF RFC3916, September 2004
13. B. Niven-Jenkins, Ed. BT D . Brung ard, Ed. AT&T M . Betts, Ed. huawei Technologies N.
Sprecher Nokia Siemens N etworks S . Ueno NTT C ommunic ations, (RFC 5654)
Requirements of an MPLS Tr ansport Profile, September 2009
14. S. Mansfield, Ed. E. Grau, Ed. Ericsson h. Lam, Ed. Alcatel-Lucent, MPLSTP N etwork
Management Fr amework, Januaru 2010
15. hing-Kam Lam, Alcatel-Lucent Sc ott Mansfield, Eric Gr au Ericsson, MPLSTP N etwork
Management Requirements, October 2009
16. Cisco Sustems, Cisc o MPLS C ontroller Software Configur ation Guid e, April 2 000
17. ITU R ecommendation G.709/U.1331, Int erfaces for the Optical Transport N etwork
(OTN), M arch 2003
18. MPLS Tr ansport Pr ofile(MPLST -TP) – A set of enhancements of Ric h MPLS T oo,
Junip er Networks 2011
19. MPLS Tr ansport Profile- Test Methodologies-IXIA November 2010
20. Packet Transport Networks: Overview and Futur e Direction 26 August 2014, B angkok,
Thailand
21. ITU-T Recommendation G.783: “Characteristics of synchronous digital hierarchy (SDH)
equipment functional blocks”, March 2003

63
22. ITU-T Recommendation G.811: “Timin g Characteristics of Primary Reference Clocks”,
September 1997
23. ITU-T Recommendation G.813: “Timing characteristics of SDH equipment slave clocks
(SEC)”, March 2003
24. http://support.huawei.com/enterprise/en/network -management/imanager -u2000 -pid-15315
25. http://opti500.cian -erc.org/opti500/pdf/sm/mpls -tp%20cisco.pdf
26. ITU-T Recommendation M.3010: “Principles for a telecommunications management
network”, February 2000 [M.3400] ITU -T Recommendation M.3400: “TMN management
functions”, February 2000