Pseudowire Switching With Protection; Figure 22: Vll Resilience With Pseudowire Redundancy And Switching - Alcatel-Lucent 7210 SAS M Service Manual

Pseudowire Switching

Pseudowire Switching with Protection

Pseudowire switching scales VLL and VPLS services over a multi-area network by removing the
need for a full mesh of targeted LDP sessions between PE nodes.
pseudowire redundancy to provide a scalable and resilient VLL service across multiple IGP areas
in a provider network.
SDP3:300
PW switching
PW switching
SDP1:100

Figure 22: VLL Resilience with Pseudowire Redundancy and Switching

In the network in
for the purpose of pseudowire signaling. A switching node will need to pass the SAP Interface
Parameters of each PE to the other.T-PE1 sends a label mapping message for the Layer 2 FEC to
the peer pseudowire switching node" for example, S-PE1. It will include the SAP interface
parameters, such as MTU, in the label mapping message. S-PE1 checks the FEC against the local
information and if a match exists, it appends the optional pseudowire switching point TLV to the
FEC TLV in which it records its system address. T-PE1 then relays the label mapping message to
S-PE2. S-PE2 performs similar operations and forwards a label mapping message to T-PE2. The
same procedures are followed for the label mapping message in the reverse direction, for example,
Page 142
Access Node
7750 T-PE2
Metro area B
7210
7210 S-PE3
Core area
7210 S-PE1
7210
Metro area A
7750 T-PE1
Access Node
Figure 22, PE nodes act as masters and pseudowire switching nodes act as slaves
7750 T-PE3
7210
7210 S-PE4
7210 S-PE2
SDP4:400
7210
7210
7210 SAS M Services Guide
Figure 22 illustrates the use of
Primary PW
Standby PW
SDP6:600
PW switching
PW switching
OSSG114-7210M