International Telecommunication Union
ITU-T
Ethernet Services over Transport
MPLS (T-MPLS)
Italo Busi
Alcatel (Editor of G.8110.1)
ITU-T Workshop “NGN and its Transport Networks“
Kobe, 20-21 April 2006
Introduction to Ethernet services over T-MPLS
ITU-T
o Transport MPLS has been defined by ITU-T as
an application of the MPLS technology for
packet transport networks.
o Ethernet services have been defined by
G.8111.x ITU-T Recommendation series as
well as by MEF Technical Specification
• Ethernet services are defined irrespectively
on the transport network technology that is
used to support them
o Transport MPLS is a packet-based transport
network technology well suited to support
Ethernet services
ITU-T Workshop “NGN and its Transport Networks“
Kobe, 20-21 April 2006
2
Introduction to Ethernet services over T-MPLS
ITU-T
o Transport MPLS networks can be used to implement
the following services:
• Point-to-point EPL/EVPL based on MEF E-Line (point-topoint EVC)
• Multipoint EVPLAN (Ethernet Virtual Private LAN) based
on MEF E-LAN (multipoint EVC)
• Rooted multipoint Services based on MEF rooted
multipoint EVC
o The implementation of Ethernet services with T-
MPLS benefit from the Transport MPLS of being both
• a packet technology (i.e. better fitting the nature of
packet services like Ethernet)
• a transport technology (i.e. a carrier-grade technology
supporting OAM and protection switching capabilities).
ITU-T Workshop “NGN and its Transport Networks“
Kobe, 20-21 April 2006
3
Point-to-point EVC over T-MPLS (PW Application)
ITU-T
PW Trail
PSN Tunnel Trail
(PE)
T.Switch
(P)
(PE)
T.Switch
T.Switch
PW architecture defined in RFC3985
PW application in T-MPLS networks defined in appendix I/G.8110
ITU-T Workshop “NGN and its Transport Networks“
Kobe, 20-21 April 2006
4
PW Application in T-MPLS (Appendix I/G.8110.1)
ITU-T
Ethernet Service Payload
Optional Control Word
TTL
PWE3
Label
S
T-MPLS trail ( PW trail)
MPLS_AP
MPLS_CI
traffic unit
T-MPLS NC ( PW NC)
EXP
Label
MPLS_AP
T-MPLS trail ( PSN trail)
TTL
Label
stack
entry
(PSN)
S
MPLS_CI
traffic unit
T-MPLS NC ( PSN NC)
EXP
Label
Server AP
Server TCP
Multiple PW’s can be muxed /demuxed
(one shown for simplicity)
Server trail
Server NC
MPLS
TM/TM_A
/ MPLS-m
ITU-T Workshop “NGN and its Transport Networks“
Kobe, 20-21 April 2006
5
PW over SDH in T-MPLS (Appendix I/G.8110.1)
ITU-T
Ethernet Service Payload
Optional Control Word
TTL
PWE3
Label
S
MPLS_AP
MPLS_CI
traffic unit
T-MPLS trail ( PW trail)
T-MPLS NC ( PW NC)
EXP
Label
VC - n
VC-n_AP
VC-n_CI
traffic unit
Sn/Sn-Xv/Sn-Xc trail
Sn/Sn-Xv/Sn-Xc NC
Server_AP
Server trail
Server_TCP
Server NC
Multiple PW’s can be muxed /demuxed
(one shown for simplicity)
VC S/TM_A
ITU-T Workshop “NGN and its Transport Networks“
Kobe, 20-21 April 2006
6
Multipoint EVC over T-MPLS
ITU-T
T.Switch
T.Switch
T.Switch
VPLS architecture defined in
draft-ietf-l2vpn-vpls-ldp-08.txt
ITU-T Workshop “NGN and its Transport Networks“
Kobe, 20-21 April 2006
7
MP EVC over Multicast T-MPLS
ITU-T
T.Switch
T.Switch
T.Switch
Work on multicast T-MPLS still on-going
ITU-T Workshop “NGN and its Transport Networks“
Kobe, 20-21 April 2006
8
R-MP EVC over T-MPLS
ITU-T
Root
Leaf
T.Switch
T.Switch
T.Switch
Leaf
A partial mesh of T-MPLS PW trails is
established connecting only UNI ports that
are allowed to speak to each other
ITU-T Workshop “NGN and its Transport Networks“
Kobe, 20-21 April 2006
9
Ethernet Services over Multi-domain T-MPLS Networks
ITU-T
o T-MPLS is designed to be a scalable end-to-
end packet transport technology
o T-MPLS supports network partitioning
• Network partitioning at the PW level is
supported in line with the multi-segment PW
architecture (draft-ietf-pwe3-ms-pw-arch00.txt)
o T-MPLS supports sub-layer hierarchy
ITU-T Workshop “NGN and its Transport Networks“
Kobe, 20-21 April 2006
10
MS-PW Application in T-MPLS
(Appendix I/G.8110.1)
ITU-T
Ethernet Service Payload
Optional Control Word
TTL
PWE3
Label
S
MPLS_AP
TTL
Label
stack
entry
(PSN)
S
T-MPLS NC ( PW NC)
MPLS_CI
traffic unit
EXP
Label
T-MPLS trail ( PW trail)
MPLS_AP
MPLS_CI
traffic unit
T-MPLS trail
( PSN1 trail)
T-MPLS trail
( PSN2 trail)
T-MPLS NC
( PSN1 NC)
T-MPLS NC
( PSN2 NC)
EXP
Label
Server AP
Server (T)CP
ITU-T Workshop “NGN and its Transport Networks“
Kobe, 20-21 April 2006
11
Conclusion
ITU-T
o Transport MPLS is a very promising carrier-
grade packet transport technology for
supporting packet services over newgeneration transport networks
o This presentation has shown how T-MPLS
networks can be used to support carriergrade Ethernet services
• Point-to-point, multipoint as well as rootedmultipoint Ethernet services can be
supported
ITU-T Workshop “NGN and its Transport Networks“
Kobe, 20-21 April 2006
12