Description: This object is used to configure a PVC protection group (or redundant group) with the PVCs protecting each other. Currently only two PVCs are supported in a protection group. One of them is primary and the other one is secondary. This is intended for PVCs designated to carry control traffic and needs to be protected. However the same PVC may also be used to carry VoIP bearer traffic or other traffic.

Channels that are 'protected (1)' share the following characteristics:

1. They are monitored for their health (including emission of traps in case of state changes).

2. An active channel is protected by another protected channel which is standby. This means when an active channel fails, switchover to another channel will happen if one is available.

3. It is also possible to do a forced switchover (through locking). Even in the case of forced switchover, switchover to another channel, which is in standby, will happen.

4. Channels may be locked to force switchover and/or to take the channel out of service in a graceful fashion.

This object takes the default value of 'unprotected (2)' during the creation of the table entry. Once the primary and secondary channels have been created as 'unprotected (2)' channels, they can be 'protected (1)' by doing a SET on the primary channel by specifying the vismChanProtection as protected and by specifying the vismChanFallbackLcn as the LCN number of the secondary channel.

The sequence of operations for setting up the 'protection (1)' group is: step 1: Add primary channel as unprotected step 2: Add secondary channel as unprotected. The PCR value for the secondary should be the same as that of the primary. step 3: Do a SET on the primary channel with vismChanProtection set to 'protected (1)' and vismChanFallbackLcn set to the LCN number of the secondary channel. This operation sets-up the protection group. The primary channel becomes active and the secondary channel becomes standby.

Please note that all the CAC related parameters for the both the PVCs in the protecting group should be same. In other words the vismChanCacMaster, vismChanCarrierLossPolicy, vismChanCacRejectionPolicy, VAD tolerance etc.. should have the same value for the PVCs that are protecting each other, else the set request to protect two channels will be rejected.

Once the protection group is setup, if the active channel fails, it automatically switches over to the standby. The standby channel then becomes active.

The channels can be removed from the protection group by setting this object to unprotected.

Deletion of a 'protected (1)' channel is not allowed. Channels have to be removed from the protection group first before deleting. The sequence of operations for deleting 'protected (1)' channels are: step 1: Remove the channels from the protection group by setting vismChanProtection to unprotected. step 2: Delete secondary channel. step 3: Delete primary channel.