The encapsulation vlan pass command enables the EVC VPWS tagged mode.
The undo encapsulation vlan pass command disables the EVC VPWS tagged mode.
By default, the EVC VPWS encapsulation mode is raw.
Usage Scenario
In an Ethernet Virtual Connection (EVC) scenario, if an EVC is configured to carry VPWS services, PWs works in raw mode (the VPWS encapsulation type is VLAN). In this case, packets are directly forwarded without having the outer VLAN tag removed when they leave a PW. After the encapsulation vlan pass command is run, the raw mode is switched to the tagged mode so that the outer VLAN tag is removed from the packets when they leave a PW.