Other reasons for label actions include:
MTU changes: LDP withdraws the previously assigned label, and re-signals the FEC with the new MTU in the interface parameter.
Clear labels: when a service manager command is issued to clear the labels, the labels are withdrawn, and new label mappings are issued.
SDP down: when an SDP goes administratively down, the VC label associated with that SDP for each service is withdrawn.
Memory allocation failure: if there is no memory to store a received label, it is released.
VC type unsupported: when an unsupported VC type is received, the received label is released.