Signaling PW status via TLV is supported as per RFC 4447. Signaling PW status via TLV is advertised during the PW capabilities negotiation phase. It is more efficient and is preferred over the label withdrawal method.
For cell mode ATM PWs, when an AIS message is received from the local attachment circuit, the AIS message is propagated to the far-end PE unaltered and PW status TLV is not initiated.