Huawei quidway s7700 Configuration Manual page 691

Quidway S7700 Smart Routing Switch
Configuration Guide - VPN
Figure 7-5 Networking diagram of the static VLL accessing the VPLS network in dual-homed
mode
CE1
As shown in
detects the fault and asks the other SPEs to delete the related MAC addresses by sending LDP
messages.
The UPEs detect the LSP status through MPLS Operation Administration & Maintenance
(OAM). If a fault is detected, the traffic switchover is performed. After the switchover, the related
VSIs on the SPEs learn the MAC addresses afresh; thus, the traffic can return through the new
SPEs. Before other SPEs learn the MAC addresses, traffic must be broadcast.
After the fault is removed, the UPE receives double VLL broadcast traffic: one from the SPEs
before the switchover, the other from the SPEs after the switchover. The UPE decides which
broadcast traffic to be thrown away. After the fault is rectified, the traffic of the UPE is not
switched back to the original LSP. This is because the SPE is not triggered to send LDP packets
to other SPEs to delete MAC addresses before detecting LSP failures.
Inter-AS VPLS
Martini and Kompella VPLSs can realize the inter-AS Option A. In the inter-AS L2VPN
network, the link type between Autonomous System Boundary Routers (ASBRs) must be the
same as the VC type. In inter-AS Option A, each ASBR must reserve a sub-interface for each
inter-AS VC. If the number of inter-AS VCs is small, Option A can be used. VPLS adopting
inter-AS Option A consumes more resources and requires more configurations.
Option C is a better solution. The devices on the SP network need only to set up the outer tunnel
on PEs in different ASs. The ASBR does not need to maintain information about the inter-AS
VPLS or reserve interfaces for the inter-AS VPLS. VSI information of VPLS is exchanged only
between PEs. Thus, resources consumption decreases and configurations do not increase.
S7700 does not support Option C.
VPLS MAC Ping and VPLS MAC Trace
As a main technology for setting up a metropolitan area network (MAN), VPLS has been widely
adopted in large scale globally. VPLS is predominant in terms of technology but its capabilities
of service detection and monitoring are weak. VPLS MAC Ping and VPLS MAC Trace are tools
for detecting connectivity and locating faults on the VPLS network.
Issue 01 (2011-07-15)
SPE1
UPE1
SPE2
Figure 7-5, if a fault occurs on the LSP between the UPE1 and the SPE1, SPE1
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SPE3
UPE2
SPE4
LDP Message
7 VPLS Configuration
CE2
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