Alcatel-Lucent 7750 - Figure 13: MC-APS Group Protects against Node Failure

Interface Configuration
7750 SR Interface Configuration Guide Page 75
the protection circuit/router is not enforced by the 7750 SR. Service or network-specific
configuration data is not signalled nor synchronized between the two service routers.
Signalling is provided using the direct connection between the two service routers. A heartbeat
protocol can be used to add robustness to the interaction between the two routers. Signalling
functionality includes support for:
• APS group matches between service routers.
• Verification that one side is configured as a working circuit and the other side is
configured as the protect circuit. In case of a mismatch, a trap (incompatible neighbor) is
generated.
• Change in working circuit status is sent from the working router to keep the protect router
in sync.
• Protect router, based on K1/K2 byte data, member circuit status, and external request,
selects the active circuit, and informs the working router to activate or de-activate the
working circuit.
Note that external requests like lockout, force, and manual switches are allowed only on the APS
group having the protection circuit.
The Figure 13 illustrates a Multi-Chassis APS group being used to protect against link, port,
MDA, IOM or node failure.
Figure 13: MC-APS Group Protects Against Node Failure
OSSG657
7750 SR A
7750 SR B
Link 1
mc-aps
group
mc-aps Signaling Link
Link 2
CE