MC synchronization groups overview

Overview

When subscriber management is enabled on an NE, the NE maintains dynamic subscriber host state information. The state information must be synchronized between the active and standby NEs in a redundant configuration to ensure that service delivery is uninterrupted if a switchover occurs.

The 7210 SAS, 7450 ESS, 7750 SR, and 7950 XRS support the creation of MC synchronization groups using Ethernet ports in Access mode.

Support for MC synchronization groups on the 7210 SAS varies depending on the chassis type and release; see the NE documentation for support information.

Note: You can create an MC synchronization group only in an existing MC peer group. See Chapter 40, MC peer groups for information about MC peer groups.

MC synchronization can be used to ensure that the following dynamic state information is synchronized:

• basic and enhanced subscriber management

• IGMP snooping in VPLS

• PIM snooping in VPLS

• IGMP on IES or VPRN group interfaces

• SRRP in VPRN

You create an MC synchronization group inside an MC peer group using a unique synchronization tag to define the pair of NEs and the two ports or LAGs on which the dynamic state information is synchronized. The synchronization is applied to all SAPs on the port or LAG that have the same synchronization tag. When only one peer in an MC peer group is managed by the NFM-P, you can configure node redundancy parameters only for the managed peer, and only from the NE properties form. See Chapter 40, MC peer groups for information about MC peer groups.

A synchronization tag can be applied to a specified VLAN range on a port or LAG. All of the SAPs in the VLAN range are assigned the synchronization tag. The SAPs that are not in the VLAN range are not synchronized.

Note: Only ports and LAGs that use dot1q or QinQ encapsulation support MC synchronization.

MC synchronization group VLAN ranges are configurable only after MC synchronization group creation.

If the NFM-P detects a port or VLAN range configuration mismatch in an MC synchronization group during NE discovery, the NFM-P raises an alarm.

MC synchronization and dual-homed L2/L3 CO

MC synchronization is typically used in a dual-homed L2 or L3 CO configuration. For example, an access node that aggregates several subscriber lines can be dual-homed to a redundant pair of NEs. Dynamic subscriber-host state information on the NE must be synchronized with the redundant peer to ensure that service delivery in unaffected if a switchover occurs. See Chapter 78, IES management and Chapter 79, VPRN service management for more information about L2 and L3 CO dual homing.

MC synchronization for dual homing requires the configuration of protocol synchronization on the MC peer group that contains the redundant NEs. See To configure an MC peer group for information about configuring protocol synchronization on an MC peer group.