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.
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.