Transport Networks andTransport MPLS
Alberto Lometti
March, 2007
2 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Agenda
1. Transport network basics
2. TMPLS rationale
3. TMPLS features
4. TMPLS standard status & perspectives
5. A multi-layer multi-technology transport network
6. Appendix: basics of GMPLS CP protocols
3 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
1 Transport network basics
4 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
“E2E” transport network
Operator A
Service provider
ClientClient Operator n
“E2E” transport network
Service
ServiceNetworkNode
Service “transparent” transport
5 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Transport service characteristics
By means of mid-long termcountermeasures againstfailures(~h ÷ ~d)
In terms of service quality,according to the differenttechnology type
By means of short termcountermeasures againstfailures(50 msec ÷ ~sec)
Maintainable
Measurable
ResilientAvailable (% UAT)
For the client For the operator
6 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
A simplified model for transport networks
Client A Client AC
lient
B
Clie
nt B
Clie
nt C
Clie
nt C
Client, requiringtransportservice
UNI, interfacebetween the client
and the serviceprovider
Logical connection, related to thetransport service and characterized bybeing continuous along the service
path within the network(end-to-end)
Physicalconnection,
i.e. thephysicaltransportmedium
Connection matrix,operating on logical
connection andallowing for service
grooming and routingMore than one layer is possible (and typically isused) at logical connection level. Each layer, is
independently operated from the other ones
NNI,interfacebetween
two networknodes
7 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Transport service functional model
Client
Client
Non intrusive monitoring:• integrity check• connectivity check• quality check
Logicalconnection
Client-server adaptation• forward defect indication
Termination:Like non intr. mon. +• backward integrity info.• backward quality info.
Connection:• forwarding• grooming
Physicalconnections
Client-server adaptation• forward defect indication
Termination:Like non intr. mon. +• backward integrity info.• backward quality info.
8 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Fiber
ConnectionConnection
Integ rityInteg rity
Remore qual.Remore qual.
Remore qual.
QualityQuality
Integ rityInteg rity
QualityQuality
ConnectionConnection
QualityQuality
Integ rityInteg rityQualitymeasurement ConnectionConnection
QualityQuality
Remote integ r.
Integ ritySilencingInteg rityInteg ritySilencing
Maintenance
Cong ruenceCong ruenceCong ruence
ConnectionConnectionConnection
QualityQualityQuality
Remote integ r.Remote integ r.
Remore qual.
ConnectionConnectionProtection
Remote integ r.
Integ rityInteg rity
ClientLogical connection
Physical connection
Simplified network model & basic OAM tools
9 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Fiber
ConnectionConnection
Integ rityInteg rity
Remore qual.Remore qual.
Remore qual.
QualityQuality
Integ rityInteg rity
QualityQuality
ConnectionConnection
QualityQuality
Integ rityInteg rityQualitymeasurement ConnectionConnection
QualityQuality
Remote integ r.
Integ ritySilencingInteg rityInteg ritySilencing
Maintenance
Cong ruenceCong ruenceCong ruence
ConnectionConnectionConnection
QualityQualityQuality
Remote integ r.Remote integ r.
Remore qual.
ConnectionConnectionProtection
Remote integ r.
Integ rityInteg rity
ClientLogical connection
Physical connection
Basic OAM tools usage: an example (1/3)
Service protection is typically based onphysical line (because it is the one that breaks)and logical connection (because it is related to
the end-to-end service within the network).
10 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Fiber
ConnectionConnection
Integ rityInteg rity
Remore qual.Remore qual.
Remore qual.
QualityQuality
Integ rityInteg rity
QualityQuality
ConnectionConnection
QualityQuality
Integ rityInteg rityQualitymeasurement ConnectionConnection
QualityQuality
Remote integ r.
Integ ritySilencingInteg rityInteg ritySilencing
Maintenance
ConnectionConnectionConnection
QualityQualityQuality
Remote integ r.Remote integ r.
Remore qual.
ConnectionConnection
Protection
Remote integ r.
Integ rityInteg rity
ClientLogical connection
Physical connection
Basic OAM tools usage: an example (2/3)
Service maintenance is typically based on physical linecheck and can be helped by logical connection and client
signals inspection; in addition downstream alarm silencing isperformed
11 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Fiber
ConnectionConnection
Integ rityInteg rity
Remore qual.Remore qual.
Remore qual.
QualityQuality
Integ rityInteg rity
QualityQuality
ConnectionConnection
QualityQuality
Integ rityInteg rityQuality
measurement ConnectionConnection
QualityQuality
Remote integ r.
Integ ritySilencingInteg rityInteg ritySilencing
Maintenance
ConnectionConnectionConnection
QualityQualityQuality
Remote integ r.Remote integ r.
Remore qual.
ConnectionConnection
Protection
Remote integ r.
Integ rityInteg rity
ClientLogical connection
Physical connection
Basic OAM tools usage: an example (3/3)
Quality of service is typically measured on the logicalconnection both at termination and non-intrusive
monitoring points; possibly also at client non-intrusivemonitoring points. Remote indications allow for
bidirectional service monitoring making enquiries to asingle system.
12 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
SDH according to simplified model
Client A Client AC
lient
B
Clie
nt B
Clie
nt C
Clie
nt C
Client: e.g.PDH, Ethernet
Logical connection:VC12, VC3, VC4
(Virtual Container)
Physical connection:STM-N
(from 155Mb/s to 10Gb/s)
Connectionmatrices operate
at VC4 and/orVC12,VC3 level
13 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
SDH (SONET) OAM – as an example
Fiber
TTId Mism .Client specif ic
AU (TU) SFClient specif ic
MS_ REIREI
MS_ REI
EXBER, DEGEXBER, DEG
AU (TU) SFClient specif ic
BIP-NClient specif ic
TTId Mism .Client specif ic
EXBER, DEGClient specif ic
AU (TU) SFClient specif icQualitymeasurement TTId Mism .Client specif ic
BIP-NClient specif ic
RDI
LOS, LOFAU (TU) AISAU (TU) SFAU (TU) SFClient AIS
Maintenance
TTId Mism .TTId Mism .TTId Mism .
EXBER, DEGEXBER, DEGEXBER, DEG
MS-RDIRDI
REI
TTId Mism .TTId Mism .Protection
MS-RDI
LOS, LOFAU (TU) SF
ClientLogical connection
Physical connection
14 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
OTN according to simplified model
Client AC
lient
B
Clie
nt B
Clie
nt C
Clie
nt C
Client: e.g. SDH(STM16, STM64)or Ethernet (GE,
10GE)
Logical connection:ODU-N (N=1, 2, 3 for λ
at 2,5Gb/s, 10Gb/s,40Gb/s)
Physical connection: OTM-x, (x λWDM signal); OTU-N (N=1, 2, 3 for λ
at 2,5Gb/s, 10Gb/s, 40Gb/s)
Connectionmatrices operateat ODU1, ODU2,
(ODU3) level
Client A
15 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
OTN OAM – as an example
ODU TTId Mis.Client specif ic
OTU SFClient specif ic
OTU_ BEIODU-BEI meas.
OTU_ BEI
EXBER, DEGDEG
OTU SFClient specif ic
BER meas.Client specif ic
ODU TTId Mis.Client specif ic
EXBER, DEGClient specif ic
OTU SFClient specif icQuality
measurement ODU TTId Mis.Client specif ic
BER meas.Client specif ic
ODU-BDI
LOS, LOFAU (TU) AISOTU SFOTU SFClient AIS
Maintenance
OTU TTId Mis.ODU TTId Mis.ODU TTId Mis.
EXBER, DEGDEGDEG
OTU-BDIODU-BDI
ODU-BEI meas.
OTU TTId Mis.ODU TTId Mis.Protection
OTU-BDI
LOS, LOFOTU SF
Fiber
ClientLogical connection
Physical connection
16 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
2 T-MPLS Rationale
17 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
TDM/WDM-based
networking
Packet/cell/frame basednetworking
Reliability, availability,OAM in service delivery
Scalability and granularity
Service delivery throughpacket-based technologies
+ PacketTransport Networking
Transport network evolution (min cost) with
(max carrier-class& flexibility)
Services
Service Evolution
Networking Requirements
Why a Packet Transport Network?
Triple Play Business Services
Migrating to data-orientedleased lines, virtual private LANs
Mobile Service Operators
Converging transport of radio acc., pt-to-pt mw, NGN services…
Driving withHSI, video, voice
18 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Packet Transport Network: Requirements
Being client-agnostic (able to carry L3, L2, L1)
Being strictly connection-oriented
Implementing strong OAM capabilities, similar to those available in existingtransport networks (e.g., SDH)
Implementing both service and line resilience mechanisms, similar to thoseavailable in existing transport networks (e.g., SDH)
Allowing for network provisioning either via a centralized management tooland/or a distributed CP
Allowing for homogeneous and/or unified management and control oftransport network when different layers are present at the same time
These requirements are the basis of ITU T-MPLS design.
19 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Expanding the Transport Network Architecture with Packets
Management Plane
Control Plane
Data Plane
Survivability (Protection, Restoration)
OAM
SDH LayersFraming, Forwarding,
Encapsulation
OTN/WDM LayersFraming, Forwarding,
Encapsulation
T-MPLS LayersFraming, Forwarding,
Encapsulation
Common multilayer operations, survivability, control and management paradigms forpackets, circuits & photonics
20 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
3 T-MPLS features
21 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Transport MPLS (T-MPLS) in Brief
Transport MPLS is a connection-oriented packet transport technology,based on MPLS frame formats.
It reuses the most widespread label swapping paradigm existing in telecom.
It inherits all IETF definition activity in terms of server and client encapsulationrules.
It profiles MPLS so that it avoids the complexity and need for IP routingcapability.
Transport MPLS defines powerful OAM capabilities that enable status &performance reports, in such a way that they remain confined within the T-MPLSlayer and do not require deeper packet inspection.
It allows for guaranteed SLAs.
It defines protection switching and restoration.
It allows for efficient fault localization and multi-operator service offering.
A Transport MPLS layer network is operated with network management and/or bya control plane.
The control plane inside the T-MPLS network is GMPLS.
22 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Client D
Client A
Clie
nt C
Clie
nt B
Clie
nt C
T-MPLS network model
Clie
nt B
Client A
Client D
Clients: in T-MPLS it canbe any L2, using mappingoptions defined by IETF
for PWE3: Ethernet, ATM,FR … ) or IP/MPLS (so faronly Ethernet formally
defined in ITU)
Physical connection: inT-MPLS it can be any L1
(Ethernet, SDH, OTN+WDM…); moreover in T-MPLS an
optional section layer isunder definition, in order
to support OAM if nototherwise available
Logical connection: inTMPLS two networking
layers are underdefinition: circuit
(equivalent to IETF PWE3)and path (equivalent to
IETF MPLS tunnel)
Logical connection: inT-MPLS two networking
layers are underdefinition: circuit
(equivalent to IETF PWE3)and path (equivalent to
IETF MPLS tunnel)
T-MPLS equipment(switching capability either
at circuit or path layer)
23 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Packet Transport Network “ideal” Modeling
Clientservices
Networkservicelayer(s)
mp2mpadaptation
p2padaptation
Logical transport(1:1 with service)
Transportlayer(s)
Logical transport(N:1 with service)
E2e & segment OAME2e & segment protectionSLA enforcement
Trunk OAM,protection & restoration(combined)Service aggregation
Recursivetransportlayer(s)
L0-L1networking
Physicallayer
EthernetSDH, OTH
“Ideal” model
Any L1 (via CES), L2, L3 service
Mp2mp and p2p adaptations may not bepart, in strict sense, of the packet transporttechnology. As an example, in VPLS mp2mpadaptation is based on Ethernet.
Two true networking layers are (at least)typically needed for a transport solution.The first layer is the carrier devoted to aspecific service, and thus allow for e2eOAM, performance monitoring andprotection. It needs not to be associatedend to end with the second layer, fornetwork scalability purposes. It is the basictool for SLA enforcement. The second layerallows mainly for aggregation and thusscalability. Restoration is possibly appliedto this layer. Of course further aggregationlayers can be recursively defined. Ingeneral, OAM and protection are data planemechanisms, generally implemented in HWfor fast and deterministic behavior.
24 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
MPLSprotocolssuite asdistributedcontrol plane
IETF MPLS:• A complete toolset for
L1/L2/L3 servicemanagement, withtransport capabilities
• IP-centric and serviceoptimized
• Coherence amongMPLS Service andTransport Layers
Packet Transport Network Modeling & MPLS
Clientservices
Networkservicelayer(s)
mp2mpadaptation
Logical transport(1:1 with service)
Transportlayer(s)
Logical transport(N:1 with service)
E2e & segment OAME2e & segment protectionSLA enforcement
Trunk OAM,protection & restoration(combined)Service aggregation
Recursivetransportlayer(s)
L0-L1networking
Physicallayer
EthernetSDH, OTH
MPLS“Ideal” model
Any L1 (via CES), L2, L3 service
MS-PW (understandardization)
MPLS PSN
VCCV
BFD, PingFRR
VPLSIP-VPN
PWVCCV
SDHOTH Ethernet
SDHOTH
p2padaptation
25 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
ITU-T T-MPLS:• A packet technology
optimized fortransport purposes
• Carrier focused• Coherence among
packet and TDM/λtransport
• MPLS used as servicelayer only
Packet Transport Network Modeling & TMPLS
Clientservices
Networkservicelayer(s)
mp2mpadaptation
Logical transport(1:1 with service)
Transportlayer(s)
Logical transport(N:1 with service)
E2e & segment OAME2e & segment protectionSLA enforcement
Trunk OAM,protection & restoration(combined)Service aggregation
Recursivetransportlayer(s)
L0-L1networking
EthernetSDH, OTH
TMPLS“Ideal” model
Any L1 (via CES), L2, L3 service
CentralizedNM orASON/GMPLSprotocolssuite asdistributedcontrol plane
TMPLS path
TMPLS circuitY.17tomG.8131 (linearprotections)
Y.17tomG.8131 (linearprotections)G.8132 (ringprotection)
VPLSIP-VPN
PW
Eth.only
L1 (CES)Any L2
SDHOTH Ethernet
SDHOTH
p2padaptation
26 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Packet Transport Network Modeling: MPLS-TMPLS synergies
Clientservices
Networkservicelayer(s)
mp2mpadaptation
Logical transport(1:1 with service)
Transportlayer(s)
Logical transport(N:1 with service)
E2e & segment OAME2e & segment protectionSLA enforcement
Trunk OAM,protection & restoration(combined)Service aggregation
Recursivetransportlayer(s)
L0-L1networking
Physicallayer
EthernetSDH, OTH
MPLS
VPLSIP-VPN
PW
MS-PW (understandardization)
MPLS PSN
TMPLS
TMPLS path
TMPLS circuit
“Ideal” model
Any L1 (via CES), L2, L3 service
TMPLS service architecture is inherited byMPLS. TMPLS enhances MPLS thanks to itstransport capabilities, in line with andoperationally similar to SDH and OTH.GMPLS CP common to packets, TDM andlambdas opens the possibility of multi-layernetwork optimizations. Identical data planesubset and encapsulation rules allow veryefficient MPLS-TMPLS inter-workingschemes. ITU “tandem connection” conceptideally complements IETF OAM capabilities.
SDHOTH Ethernet
SDHOTH
SDHOTH Ethernet
SDHOTH
p2padaptation
27 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
T-MPLS Survivability
Protection (data plane) <50 ms with automatic protection switch
(APS) protocols on data plane OAM channels 1+1, 1:1, N:1 (no extra traffic) Unidirectional, bidirectional Section, path, circuit Subnetwork connection (SNCP) Ring Dual node interconnect (DNI)
T-MPLS
ClientEquipment
Restoration (control/management plane) Distributed control plane (ASON/GMPLS) Full LSP rerouting restoration Pre-planned LSP rerouting restoration Any topology (mesh) GMPLS-based restoration in synergy with
other transport network technologies (SDH,OTN, WDM)
RingProtect
DNI
Circuit & PathProtection
Section Protection
ClientEquipment
28 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
T-MPLS OAM
T-MPLS
Y.1711 - Y.17tomOAM primitives
Not applicable
Loopback
Frame Loss, Frame
Delay, FDV
Link Trace
(ffs)
Loopback
On demand
FDISilencing
BDIRemote integrity
PM (carried by FFD)Quality
FFDConnectivity
FFD, CVIntegrity
Continuous
Standardized
Ongoing
29 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
T-MPLS OAM according to ITU is contained in MPLS frames associated to the connection by therelevant LSP (outer) label and characterized by an (inner) label 14. OAM information is
contained within the MPLS payload.
Fiber (λi)
Client
Logical Connection
Physical Connection
QualityMeasurement
Maintenance
Protection
Link TraceClient specific
CV, FFDClient specific
Server specificRemote quality
Server specific
Server specificPM
CV, FFD,Client specific
PMClient specific
CV, FFDClient specific
PMClient specific
CV, FFD,Client specific
CV, FFDClient specific
PMClient specific
BDI
Server specificFDICV, FFDCV, FFDSilencing
Server specificCV, FFDCV, FFD
Server specificPMPM
Server specificBDI
Remote quality
Server specificFFD (via TTSId)
Server specificBDI
Server specificFFD
T-MPLS OAM(according to ITU-T Y.1711, Y.17tom)
30 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
T-MPLS Control Plane (ASON/GMPLS)
GMPLS is a single, generalized distributed control plane that can be used incommon for multiple networking technologies, including packets, TDM andphotonicsGMPLS defines: UNI concept (thus easing overlay dynamic approach) I(nternal)-NNI concept (the only supported in MPLS CP) E(xternal)-NNI concept (thus allowing for interworking among different
vendors/operators) Bidirectional pathsGMPLS allows for separation of data plane and control plane Only control interfaces are used to flood control informationGMPLS allows for “horizontal” scalability in routing domains (thanks toseparation of data plane and control plane and recursive topology)GMPLS allows for “vertical” scalability (same control plane across differentlayers)
GMPLS is the ideal control plane for multilayered networks
31 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
4 T-MPLS Standard Status & Perspectives
32 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Protection G.8131
OAM Y.17tom
GMPLS ProtocolsControl Plane &
Restoration(IETF)
T-MPLS Standards Framework
MPLS Architecture/
Protocols(IETF)
Carrier-grade packet forwarding best from IETF
Carrier-grade control planebest from IETF
TMPLSFramework
Contribute
T-MPLS InterfacesG.8112
T-MPLS EquipmentFunctional Blocks
G.8121
Architecture of T-MPLS Layer
Network G.8110.1
ASON ArchitectureG.8080
Best from ITU
33 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Transport Network Standard Overview
T-MPLSstandard status
Amend. 1 (ring) to beconsented Jun07
Y.1720 approvedG.8131 v1 (adaptationto T-MPLS) consented
Version 1 approvedAmend. 1 (p2mp,protection) to beconsented Mar-Jun07
Y.1711 approvedY.17tom (ext. OAM, TC)to be consented Apr07
Version 1 approvedAmend. 1 (p2mp) to beconsented Mar-Jun07
Version 1 approvedAmend. 1 (p2mp,extended OAM) to beconsented Mar-Jun07
SDH OTH T-MPLSC.O. G.805C.L. G.809
G.873.2 (frozen)
G.808.2(frozen)
Y.17tom (Y.1711)
G.8121 (G.mplseq) G.806
G.808.1
----
G.8131 (Y.1720)
G.803 G.872 G.8110.1
G.841
G.709
G.8132Ring Protection
Linear Protection G.873.1
Network Architecture
Equipment G.783 G.798
UNI & NNI Interface
OAM [frame format]
G.707
Connection Oriented(G.805) Generic
C.O. + C.L. G.uftan
G.8112 (G.motnni) ----
34 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
5 A multi-layer multi-technologytransport network
35 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Data-centric network abstraction
ADMADM
ADMADM
Layer 1 (TDM and/or λ)
XC
XC
XCXC
Layer 2CE
L2(L3) businessservices
Residential services
PE
Layer 3
Metro aggregation CoreAccess
ADMADM
ADMADM
Mobile services
CPE (res.)
CPE (bus.) Aggregationtier 1
Aggregationtier 2
Edge
Outer Core Inner Core
BB access ADMADM ADMADMXC XC
Optical AccessCPE (bus.)
36 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Key transport networking needs
•Ethernet demarcation at(business) user-network interface
•Circuit emulation capabilitiesin order to cross pure packetbased access areas with legacy,TDM based, services
•Multi-service encapsulationcapability, for convergingdifferent types of L2 services(ATM, FR, Ethernet …) on acommon packet infra-structure inview of coherent end-to-endservice management
•Optical access solutions forFTTx, either point-to-point orWDM PON based
Access
CPE (res.)
•Multi-service aggregationcapability, for converging newbusiness and residential packetbased with legacy ones along with2G and 3G mobile backhauling
•Strong OAM capabilities, andefficient (linear & ring)protections to manage andmaintain the growing-in-sizeaggregation network, whileoptimizing OPEX
•Capability of mixing optical andelectronic aggregationcapabilities, according to the realneeds, in order to optimize CAPEX
•QoS management for businessservices and for residential beyondInternet access
Metro
CPE (bus.)
BB access
CPE (bus.)
•Multi-service transportcapability, for converging IP/MPLStraffic coming from edge/outercore routers with clear channel(carrier’s carrier) type services,evolving to very fat pipes (10Gb/s⇒ 40Gb/s ⇒ 100Gb/s)
• OAM capabilities in line withtraditional transport services overgeographical distances
•Distributed restoration, in orderto fully exploit the meshed natureof core networks
•“Coarse” QoS, traffic andgranularity managementaccording to the nature ofaggregated streams in core network
Core
Aggregationtier 1
Aggregationtier 2
Edge
Outer Core Inner Core
ADMADM ADMADMXC XC
Optical Access
37 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Key transport networking needs: metro and access
•Ethernet demarcation at(business) user-network interface
•Circuit emulation capabilitiesin order to cross pure packetbased access areas with legacy,TDM based, services
•Multi-service encapsulationcapability, for convergingdifferent types of L2 services(ATM, FR, Ethernet …) on acommon packet infra-structure inview of coherent end-to-endservice management
•Optical access solutions forFTTx, either point-to-point orWDM PON based
Access
CPE (res.)
•Multi-service aggregationcapability, for converging newbusiness and residential packetbased with legacy ones along with2G and 3G mobile backhauling
•Strong OAM capabilities, andefficient (linear & ring)protections to manage andmaintain the growing-in-sizeaggregation network, whileoptimizing OPEX
•Capability of mixing optical andelectronic aggregationcapabilities, according to the realneeds, in order to optimize CAPEX
•QoS management for businessservices and for residential beyondInternet access
Metro
CPE (bus.)
BB access
CPE (bus.)
•Multi-service transportcapability, for converging IP/MPLStraffic coming from edge/outercore routers with clear channel(carrier’s carrier) type services,evolving to very fat pipes (10Gb/s⇒ 40Gb/s ⇒ 100Gb/s)
• OAM capabilities in line withtraditional transport services overgeographical distances
•Distributed restoration, in orderto fully exploit the meshed natureof core networks
•“Coarse” QoS, traffic andgranularity managementaccording to the nature ofaggregated streams in core network
Core
Aggregationtier 1
Aggregationtier 2
Edge
Outer Core Inner Core
ADMADM ADMADMXC XC
Optical Access
TMPLS allows for a convergent packet platform forany L2 protocol, thanks to a concept analogous toPWE3 as defined by IETF. On top of this, TMPLSadds OAM tools, linear and ring protection schemesand the possibility of a distributed control plane, all ofthem coming from transport experience, defined byITU and in common with other transport technologies.Multicast capabilities are as well under definition.
TMPLS allows for a convergent packet platform forany L2 protocol, thanks to the PWE3 concept definedby IETF. On top of this, TMPLS adds transportspecific OAM tools, linear and ring protectionschemes along with the possibility of GMPLSdistributed control plane, that is in common withother, TDM and λ based, transport technologies.Multicast capabilities are as well under definition.
38 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Key transport networking needs: core
•Ethernet demarcation at(business) user-network interface
•Circuit emulation capabilitiesin order to cross pure packetbased access areas with legacy,TDM based, services
•Multi-service encapsulationcapability, for convergingdifferent types of L2 services(ATM, FR, Ethernet …) on acommon packet infra-structure inview of coherent end-to-endservice management
•Optical access solutions forFTTx, either point-to-point orWDM PON based
Access
CPE (res.)
•Multi-service aggregationcapability, for converging newbusiness and residential packetbased with legacy ones along with2G and 3G mobile backhauling
•Strong OAM capabilities, andefficient (linear & ring)protections to manage andmaintain the growing-in-sizeaggregation network, whileoptimizing OPEX
•Capability of mixing optical andelectronic aggregationcapabilities, according to the realneeds, in order to optimize CAPEX
•QoS management for businessservices and for residential beyondInternet access
Metro
CPE (bus.)
BB access
CPE (bus.)
•Multi-service transportcapability, for converging IP/MPLStraffic coming from edge/outercore routers with clear channel(carrier’s carrier) type services,evolving to very fat pipes (10Gb/s⇒ 40Gb/s ⇒ 100Gb/s)
• OAM capabilities in line withtraditional transport services overgeographical distances
•Distributed restoration, in orderto fully exploit the meshed natureof core networks
•“Coarse” QoS, traffic andgranularity managementaccording to the nature ofaggregated streams in core network
Core
Aggregationtier 1
Aggregationtier 2
Edge
Outer Core Inner Core
ADMADM ADMADMXC XC
Optical Access
TMPLS is an ideal packet platform foredge router interconnection,leveraging on MPLS pipes as natural“channels” of the router interfaces, tobe used in order to classify traffic andforward it through a TMPLS tunnel toits due destination. Besides commonwith other transport layers OAM andprotection like in metro, GMPLScontrol plane adds the possibility ofpath setup and restoration jointly atpacket/TDM/λ level. The conceptual,and then physical, distinction between“service” (IP/MPLS) and “transport”(TMPLS) allows for the design ofsystems the complexity (and cost) ofwhich is correctly tailored to transportneeds.
39 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Network vision: aggregation networks layers usage
Packets, framesTransparency
TMPLS prot.Resiliency
TMPLSNetworking
Eth, ATM, FR ...Clients
TMPLS network (stat.mux.) layer
TMPLS for statistical multiplexing, SDH for transparent transport, λ for optical bypass
VCx, bit streamTransparency
SDH prot.Resiliency
VCx, VCx-ncNetworking
PDH, SDH, “Any”Clients
SDH network layer
STM-NTransparency
NAResiliency
NANetworking
STM-NClients
ODU adaptation (OAM) layer
OTU1, OTU2Transparency
Och prot.Resiliency
OchNetworking
OTU1, OTU2Clients
Och network layer
Och (λ)
XC
λ
λXC
XC XC
ODU
ODU
ODU
ODU ODU
ODU
SDH
TMPLS
XCReal networking
Pure adaptationλ
ODU
40 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Network vision: core networks layers usage
TMPLS for statistical multiplexing, SDH and OTH (seen as ODU + λ) for transparent transport
Och (λ)
XC
λ
λXC
XC XC
Packets, framesTransparency
TMPLS restor.Resiliency
TMPLSNetworking
PoS, Eth(Martini)Clients
TMPLS network (stat.mux.) layer
VC4, framesTransparency
VC4 restor.Resiliency
VC4, VC4-ncNetworking
STM-N, EthernetClients
SDH network layer
STM-N, PHYTransparency
ODU restor.Resiliency
ODUNetworking
STM-N, EthernetClients
ODU network layer
(OTU1), OTU2Transparency
λ restor. (tba)Resiliency
λNetworking
(OTU1), OTU2Clients
Och network layer
ODUODU
ODU ODU
ODU
SDH
TMPLS
XCReal networking
Pure adaptationλ
ODU
41 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
Och (λ)
XC
XC
XCXC
XC XC
ODUODU
ODU
ODU
Core transport network: target vision
OTH progressively replacing SDH, integrated packet/ODU/λ networking
Packets, framesTransparency
TMPLS/GMPLSRestoration
TMPLSNetworking
PoS, Eth(Martini)Clients
TMPLS network (stat.mux.) layer
STM-N, PHYTransparency
λ+ODU /GMPLSRestoration
ODUNetworking
STM-N, EthernetClients
ODU network layer
(OTU1), OTU2Transparency
λ+ODU /GMPLSRestoration
λNetworking
(OTU1), OTU2Clients
Och network layer
TMPLS
XCReal networking
Pure adaptationλ
ODU
42 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
TMPLS within the target network vision
ADMADM
ADMADM
Layer 1 (TDM and/or λ)
XC
XC
XC
ADMADM
CEs
Network vision is based on multi-service node concept, able to support both residential(wireline/wireless) and business services, in which TMPLS technology is chosen as aconverged packet network able to support any service type (Ethernet, IP/MPLS, FR, ATM, TDMvia CES, …) along with GMPLS distributed control plane, common also for TDM and λ layers.
PE
Layer 3
TMPLS (layer 1.5)
L2(L3) businessservices
Residential services
CPE
Layer 2
Mobile services
CPE
ADMADM XC
43 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
6 Appendix: basics of GMPLS CP protocol
44 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
GMPLS versus MPLS: key points
UNI GMPLS defines
A UNI concept (thus easing overlay dynamic approach)
A I(nternal)-NNI concept
A E(xternal)-NNI concept (thus allowing for inter-working among different operators)
MPLS implies the concept of (internal) NNI only Note that hierarchical OSPF is not defined today neither for MPLS nor for GMPLS
GMPLS defines a link protocol LMP: it discovers which (user or network) interfaces are connected to a link and allows for
detecting which type of service (TDM, packet, λ) is available at a UNI
Control plane and data plane GMPLS allows for a separation of data plane and control plane
Only control interfaces are used to flood LSAs
In MPLS every data interface has to be also a control interface And thus flood LSAs
Path concept Unidirectional in MPLS, packet only Bi-directional in GMPLS, multi-layer
45 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
GMPLS versus MPLS: OSPF flavours
OSPF in general• OSPF is a link state routing protocols• OSPF advertises to all the node of the network its adjacencies via LSA (Link State Advertisements)• Every node builds up the entire network topology and evaluates the shortest path for each destination
OSPF
TopologydB
OSPF for IP• Data plane = control plane• LSA refers to all interfaces• One topology dB is built up
OSPF-TE
ControlTopology
dB
CSPF
OpaqueLSAdB
DataTopology
dB
OSPF for MPLS• Data plane ≠ control plane (in termsof routes, not of topology)
• Data plane can be constrained• OSPF builds the control topology dB• Opaque LSA are used to advertisedata plane ports but are notmanaged by OSPF
• CSPF builds up the data top. dB
OSPF-TE
ControlTopology
dB
CSPF
OpaqueLSAdB
DataTopology
dB
OSPF for GMPLS• Same as MPLS, with extensionsin order to:
• Describe non packet i/fs• Managing TE link bundlingfor scalability (N p2p i/fs areadvertised as 1)
• Transmitting several opaqueLSAs in 1 IP (OSPF) packet
46 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
GMPLS versus MPLS: RSVP-TE
RSVP-TE for MPLS
Defines unidirectional paths
The IP packet containing RSVP signaling hasthe path terminal node as DA (i.e. has tofollow the path)
In signaling N paths between A and B acompression can be done using one single IPmessage for all the relevant information(saving the header overhead)
RSVP-TE for GMPLS
Defines bidirectional paths (so the signalingtraffic and the number of state machines is½ of MPLS)
The IP packet containing RSVP signaling hasthe next path hop as DA (i.e. can follow adifferent route wrt a data packet to reachthe node)
In signaling N paths between A and B acompression can be done putting in a singleIP message only the path identifiers (andnot the paths characteristics that are alreadyknown)
A B
“Path” signalling
ACK ACK ACK ACK
ACK ACK ACK ACK
“ResV” signalling
RSVP-TE• Defines a finite state machine for each path that is set-up• The “Path” signal contains the route (ERO: Explicit Routing Object)• The “ResV” signal allocates the resources and distributes the labels• Path and ResV signals are output periodically to maintain the path (soft state)
47 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
GMPLS UNI concept
Servernetwork
Clientnetwork
Clientnetwork
GMPLS engine
MPLS engine
UNIUNI
RSVP-TEGMPLS
A B C D
The MPLS engine uses the [servertechnology] connection established by
GMPLS as forwarding adjacency
OSPF-TEGMPLS
NNI NNI
NNINNI
GMPLS connection (λ, TDM, packet)
The GMPLS engine asks a “loose source routed”[server technology] connection from A to D
through B and C. Reachability information betweenA and D has to be known “a priori”. Connectionbetween B and C is routed based on topologyinformation exchanged among GMPLS NNI’s.
48 | Transport MPLS Rationale and Features | February 2007 All Rights Reserved © Alcatel-Lucent 2006, 21407
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