LDP pseudowire auto-sensing

Label Distribution Protocol (LDP) pseudowire auto-sensing addresses zero-touch provisioning. LDP pseudowire auto-sensing enables pseudowire headend termination to be dynamically provisioned rather than statically configured. Hence, it is referred to as zero-touch provisioning. In Junos OS, pseudowire headend termination on service nodes is supported through the use of pseudowire service logical interfaces and physical interfaces. This approach is considered as superior in scalability to the old logical tunnel interface based approach, due to its capability of multiplexing and demultiplexing subscribers or customers over a single pseudowire. Currently, the creation and deletion of the pseudowire service logical interfaces, pseudowire service physical interfaces, Layer 2 circuits, and Layer 2 VPNs for pseudowire headend termination rely on static configuration. This is not considered as ideal from the perspective of scalability, efficiency, and flexibility, especially in a network where each service node might potentially host a large number of pseudowires.