This object is used to indicate number of protocols
associated with this MGC group.
The value zero means there is no protocol associated with
this MGC group.
When the entry create, this object is set to 0.
The association between protocol and MGC group is configured
via cMgcGrpProtocolTable.
After a protocol is associated/de-associated with this
MGC group, this object will be incremented/decremented
by 1.
If this object is zero, it is not allowed to associate
the MGC group with any profile or gateway.