Alcatel-Lucent 7750 SR - Spoke SDP Redundancy into IES;VPRN; Figure 132: Active;Standby VRF Using Resilient L2 Circuits

Virtual Private Routed Network Services
7750 SR OS Services Guide Page 1079
Spoke SDP termination on an IES or VPRN provides the ability to cross-connect traffic entering
on a spoke SDP, used for Layer 2 services (VLLs or VPLS), on to an IES or VPRN service. From
a logical point of view the spoke SDP entering on a network port is cross-connected to the Layer 3
service as if it had entered using a service SAP. The main exception to this is traffic entering the
Layer 3 service using a spoke SDP is handled with network QoS policies instead of access QoS
policies.
When a SAP Down or SDP binding down status message is received by the 7750 PE in which the
ipipe or Ethernet spoke-sdp is terminated on an IES or VPRN interface, the interface is brought
down and all associated routes are withdrawn in a similar way when the spoke-sdp goes down
locally. The same actions are taken when the standby T-LDP status message is received by the
7750 IES/VPRN PE.
This feature can be used to provide redundant connectivity to a VPRN or IES from a PE providing
a VLL service, as shown in Figure 132.
Figure 132: Active/Standby VRF Using Resilient L2 Circuits
Spoke SDP Redundancy into IES/VPRN
This feature can be used to provide redundant connectivity to a VPRN or IES from a PE providing
a VLL service, as shown in Figure 132, using either epipe or ipipe spoke-SDPs.
In Figure 132, PE1 terminates two spoke-SDPs that are bound to one SAP connected to CE1. PE1
chooses to forward traffic on one of the spoke SDPs (the active spoke-SDP), while blocking traffic
on the other spoke-SDP (the standby spoke-SDP) in the transmit direction. PE2 and PE3 take any
spoke-SDPs for which PW forwarding standby has been signaled by PE1 to an operationally down
state.
A
VPRN
IP/MPLS
PE3
PE1
ipipe or epipe PWs
CE1
OSSG407
VRF /
IEB
A
A
ATM, FR, Ethernet
or PPP
S
PW2 (Standby)
PW1 (Active)
PE2
VRF /
IEB