SVC VPWS is an L2VPN technology that uses manually configured VC labels for data transmission. Unlike LDP VPWS, which uses LDP to exchange VC labels, SVC VPWS uses VC labels manually assigned on the PE according to the VC ID. The SVC mode can be regarded as the simplified LDP mode.
A VC label of a VPWS in SVC mode is statically configured and does not require VC label mapping, avoiding the need of LDP to transmit VC labels.
Specifying the outer label (which identifies a public tunnel) in SVC mode is similar to that in LDP mode. The inner label is specified manually during the VC configuration. PEs do not need the signaling protocol to transmit VC labels. The network topology and packet exchange process in SVC mode are similar to those in LDP mode.
When creating a static Layer 2 VC connection in SVC mode, you can specify a tunnel type, such as LDP or TE. In addition, you can configure a tunnel policy for tunnels to work in load balancing mode.