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NOTE
When you associate PW redundancy with E-APS, setting the PW redundancy to the independent mode is
recommended.
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When a single bypass PW is established and the E-APS 1:1 bidirectional mode is used
The E-APS 1:1 bidirectional mode allows high channel utilization. A bidirectional fault
detection (BFD) session is configured on two E-APS-enabled routers to track PWs and is
bound to a trunk interface to which E-APS-enabled interfaces are added. This allows E-
APS switching to trigger a primary/secondary PW switchover.
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When dual bypass PWs are established and the E-APS 1+1 bidirectional mode is used
Dual bypass PWs are established between two E-APS-enabled routers. E-APS 1+1 allows
more rapid traffic switching and higher reliability than E-APS 1:1. On a network where E-
APS 1+1 is associated with PW redundancy, dual bypass PWs must be established to protect
traffic on both primary and secondary PWs.
A BFD session can be configured to track AC-side interfaces in the E-APS group. This
speeds up E-APS switching because BFD can rapidly detect a fault and notify the E-APS
group of the fault. In addition to two bypass PWs, two mPWs are established between the
two E-APS-enabled routers. The BFD session is established to track the mPWs and bound
to the AC-side interfaces on the two router. The E-APS group on the AC-side interfaces is
configured to track the BFD session.
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When dual bypass PWs are established and the E-APS 1+1 unidirectional mode is
used
The configurations in this scenario are similar to the previous scenario, with the exception
that the AC-side interfaces must be configured to retain the Up state so that there is no
status change that will cause bypass PW configurations to be deleted.
3.2 Configuring Single-Device APS
Two devices that support APS can connect through two links. Link reliability can be improved
by configuring single-device APS.
3.2.1 Before You Start
Before configuring single-device APS, familiarize yourself with the usage scenario, complete
the pre-configuration tasks, and obtain the data required for the configuration.
Applicable Environment
APS needs to be configured when the router is connected to a Radio Network Controller
(RNC). As shown in
, PE2 and BSC (RNC) are connected by two CPOS links. You
can configure CPOS 3/0/1 as a working interface, and CPOS 3/0/2 as a protection interface.
HUAWEI NetEngine80E/40E Router
Configuration Guide - Reliability
3 APS Configuration
Issue 02 (2014-09-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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