Label withdrawal is negotiated during the PW status negotiation phase and needs to be supported by both the near-end and the far-end points. If the far end does not support label withdrawal, the 7705 SAR still withdraws the label in case the local attachment circuit is removed or shut down.
Label withdrawal occurs only when the attachment circuit is administratively shut down or deleted. If there is a failure of the attached circuit, the label withdrawal message is not generated.
When the local circuit is re-enabled after shutdown, the VLL must be re-established, which causes some delays and signaling overhead.