1. Dual-Homing Protection for MPLS and MPLS-TP Pseudowires
Weiqiang Cheng, L. Wang, H. Li (China Mobile)
K. Liu, J. Dong (Huawei)
S. Davari (Broadcom)
A. D'Alessandro (Telecom Italia)
IETF91 PALS Honolulu

2. Background Work was presented in IETF 88 and 90
Split the draft according to PWE3 chairs’ suggestion:
Framework and scenarios of dual-homing PW protection
Protocol extensions for dual-homing protection with static MPLS-TP PWs

3. Benefits of Dual-homing Protection
Local protection
Avoid PW switchover due to AC failure
Avoid AC switchover due to PW failure
PSN tunnel protection is no longer a MUST

4. PE Architecture Update
Dual-homing PE Device
Forwarder
DNI PW
Service PW
Peer Dual-homing PE Device AC
DNI PW between dual-homing PEs can carry traffic during failure
Forwarder is responsible for switching traffic between AC, service PW and DNI PW.

5. dual-homing coordination
One-side Dual-homing Scenario
PE3
PE1
PE2
CE2
CE1
DNI PW
linear protection
Working PW
Protection PW AC
Redundancy
Mechanism
dual-homing coordination
Service PW
AC1
AC2
Can Provide protection for:
AC failure
PE failure
PSN network failure

6. One-side Dual-homing Scenario
PE3
PE1
PE2
CE2
CE1 1
DNI PW
linear protection
Working PW
Protection PW AC
Redundancy
Mechanism
dual-homing coordination
AC1
AC2
Can Provide protection for:
AC failure
PSN network failure
PE failure

7. One-side Dual-homing Scenario
PE3
PE1
PE2
CE2
CE1 2
DNI PW
linear protection
Working PW
Protection PW AC
Redundancy
Mechanism
dual-homing coordination
AC1
AC2
Can Provide protection for:
AC failure
PSN network failure
PE failure

8. One-side Dual-homing Scenario
PE3
PE1
PE2
CE2
CE1 3
DNI PW
linear protection
Working PW
Protection PW AC
Redundancy
Mechanism
dual-homing coordination
AC1
AC2
Can Provide protection for:
AC failure
PSN network failure
PE failure

9. Two-side Dual-homing Scenario
PE3
PE2
CE2
CE1
DNI PW
linear protection
Working PW
Protection PW AC
Redundancy
Mechanism
AC1
AC2
PE1
redundancy
mechanism 4 2 3 5 1
Can Provide protection for:
AC failure
PE failure
PSN network failure

10. General Procedures
Dual-homing PEs need to exchange PW state and switchover coordination request to synchronize the protection switching
Forwarding behavior of dual-homing PE is determined by:
Status of Service PW
Status of AC
Status of DNI PW AC
Service PW
DNI PW
Service PW AC
DNI PW
Forwarding Behavior
Active Up
Service PW <-> AC
Standby
Service PW <-> DNI PW
DNI PW <-> AC
Drop all packets

11. Next Steps
Solicit comments from WG
WG adoption?