This MIB is used to support MGC(call agent) and 
MGC Group configuration. 
The MGC or MGC group configuration is performed 
under a specific gateway(cmgwIndex).

The call agent is an external element (outside
of gateway) with call control intelligence
to control call connection in gateway.
The protocols used for communication between voice 
gateway and call agent included SGCP, MGCP, ...

Multiple IP addresses can be associated with one 
call agent.

An MGC group is a logical grouping of several MGCs
into one group.

MGC redundancy is used to support multi call agent
for one gateway. With MGC redundancy, a voice 
gateway can send gateway-initiated-commands to the 
next MGC in the MGC group if it fails to receive 
response from any IP address(es) associated to the 
current MGC. 

To use MGC redundancy in gateway:

Step 1: add individual entry (in any order) for

  profile   
  MGC 

Step 2: make association between the entries 

1   IP with MGC            
2   MGC with MGC group   

1/2 protocol with MGC group 

3   MGC group with profile   
    or
    MGC group with gateway

 Only if a MGC group at least is associated with 
 one profile or gateway, then the MGC group can be 
 used, otherwise the MGC group is useless.

 To delete the following entries, it is needed to 
 do de-association first:

   profile   
   MGC      

 When do de-association, the order is opposite to that
 of association.