Label Withdrawal Delay at Ingress

Label withdrawal delay at ingress provides a timer that defers the reaction of LDP to session down and routing events to allow the network to stabilize. By default, LWD at ingress is enabled along with the LWD transit automatically and does not require configuration.

Label Withdraw Delay improves network convergence for an LDP network by avoiding sending Label Withdraw protocol messages after specific events in the network. It is helpful for performance at ingress nodes that have not advertised a label to an upstream peer.

LWD at ingress has the following benefits:

Reduces outage time for traffic originating from ingress tunnels.
Reduces message generation within internal MPLS modules.

This feature starts the LWD timer even for purely ingress FECs. The behavior is the same as for the FEC with upstream labels other than procedures for cleaning up the upstream labels on LWD expiration.

The use cases for LWD remain intact with the adjustment that the timer is started even when there are no upstream labels.