4.4.4.4:100:32770 Hot-Standby -- 0/0 Tunnel1/0/0
1.1.1.1:100:32770 Hot-Standby Stop 0/0 Tunnel1/0/0
10.7 Configuring Bit-Error-Triggered Switching for PW
Redundancy
This section describes how to configure bit-error-triggered switching for pseudo wire (PW)
Redundancy.
Usage Scenario
In a scenario in which a Resource Reservation Protocol-Traffic Engineering (RSVP-TE) tunnel
with traffic engineering (TE) hot-standby protection carries Layer 2 virtual private network
(L2VPN) services and PW redundancy is configured, you can configure bit-error-triggered
switching for PW redundancy in addition to bit-error-triggered RSVP-TE tunnel switching. If
the primary and backup constraint-based routed label switched paths (CR-LSPs) of the RSVP-
TE tunnel are both in the excessive bit error rate (BER) state or the TE hot-standby CR-LSP
fails and bit-error-triggered RSVP-TE tunnel switching cannot protect services against bit errors,
bit-error-triggered switching for PW redundancy can do so.
The principles for bit-error-triggered switching for PW redundancy are as follows:
l
If the RSVP-TE tunnel carrying the primary PW enters the excessive BER state but the
RSVP-TE tunnel carrying the secondary PW is in the normalized BER state, traffic switches
to the secondary PW.
l
If the RSVP-TE tunnel carrying the primary PW enters the normalized BER state, traffic
switches back to the primary PW.
l
If the RSVP-TE tunnels carrying the primary and secondary PWs are both in the excessive
BER state, traffic travels along the primary PW.
NOTE
The bit error status of the RSVP-TE tunnel carrying the PW refers to the bit error status of the CR-LSP
that transmits traffic in the tunnel.
A PW can be either a single-segment PW (SS-PW) or a multi-segment PW (MS-PW):
l
For an SS-PW, bit-error-triggered protection switching is enabled on endpoint provider edges (PEs).
l
For an MS-PW, bit-error-triggered protection switching is enabled on both endpoint PEs and
intermediate superstratum provider edges (SPEs).
Pre-configuration Tasks
Before configuring bit-error-triggered switching for PW redundancy, complete the following
tasks:
l
Configure PW redundancy.
l
Configure bit-error-triggered RSVP-TE tunnel switching.
Procedure
l
Enable bit-error-triggered protection switching for an SS-PW. The following steps must
be performed on both end PEs.
HUAWEI NetEngine80E/40E Router
Configuration Guide - Reliability
10 Bit-Error-Triggered Protection Switching Configuration
Issue 02 (2014-09-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
1014