Description: The value of vRtrIfCpmProtPolicyId associates a CPM Protection policy
with an interface.

A value of zero (0) specifies that no CPM Protection policy is
associated with this interface.

A value of one (1) specifies that the default CPM Protection policy is
associated with this interface.

If no value for vRtrIfCpmProtPolicyId is specified when the
vRtrIfEntry is created, the system assigns a default value,
derived from the value of the object vRtrIfType, as follows:

vRtrIfType              vRtrIfCpmProtPolicyId
---------------------------------------------------------------------
network                 1
service                 used internally.
serviceIes              1
serviceRtdVpls          obsoleted.
serviceVprn             1
serviceIesSubscriber    0
serviceIesGroup         0
serviceVprnSubscriber   used internally.
serviceVprnGroup        0
serviceIesRedundant     0
serviceVprnRedundant    0
serviceVpls             0
serviceIesCem           defined on a SAP. --not supported
serviceVprnCem          defined on a SAP. --not supported
serviceVprnIPsec        0
serviceVprnIPMirror     0

If an interface would get a default value of 'one', it is not
allowed to set the value of vRtrIfCpmProtPolicyId to 'zero'.

If an interface would get a default value of 'zero', it is not
allowed to modify the value of vRtrIfCpmProtPolicyId.

This object is not supported on SR-1 and ESS-1, where the
value of TN-CHASSIS-MIB::tmnxChassisType is '5',
and 7710, where the value of TN-CHASSIS-MIB::tmnxChassisType is
'7' or '9'.