This object contains an unused value for
cmplsTeP2mpTunnelDestSubGroupID, or a zero to indicate that
none exists. Negative values are not allowed, as they do not
correspond to valid values of
cmplsTeP2mpTunnelDestSubGroupID.
Note that this object offers an unused value for an
cmplsTeP2mpTunnelDestSubGroupID value at the local LSR when
it is a sub-group originator. In other cases, the value of
cmplsTeP2mpTunnelDestSubGroupID SHOULD be taken from the
received value signaled by the signaling protocol and
corresponds to the value in
cmplsTeP2mpTunnelDestSrcSubGroupID.