encapsulation rfc4761-compatible

Usage Scenario

RFC 4761 defines that the encapsulation type of Kompella VPLS packets is 19. Huawei defines 4 for VLAN encapsulation and 5 for Ethernet encapsulation for Kompella VPLS. Therefore, the encapsulation type of Kompella VPLS packets needs to be modified when Huawei devices communicate with non-Huawei devices.

When the device sends Kompella VPLS packets, run the encapsulation rfc4761-compatible command to enable the device to modify the encapsulation type of Kompella VPLS packets from Type 4 or 5 to Type 19. When the device receives Kompella VPLS packets, the device modifies the encapsulation type of Kompella VPLS packets from Type 19 to Type 4 or 5 automatically without running any command.

When the device works as a PE, the encapsulation type is determined by the CE access mode. If the CE accesses the PE in VLAN mode, the PE encapsulates packets sent by the CE in Type 4. If the CE accesses the PE in Ethernet mode, the PE encapsulates packets sent by the CE in Type 5. VLAN and Ethernet modes are described as follows:

• VLAN: Ethernet frames transmitted between the CE and PE are attached with a VLAN tag. The tag is a service delimiter required by an ISP to differentiate clients. It is also called P-tag.

• Ethernet: Ethernet frames transmitted between the CE and PE do not have a service delimiter. If the header of Ethernet frames carries a VLAN tag, this tag is the inner VLAN tag of user packets, and is of no use to the PE. It is also called U-tag.

Precautions

The encapsulation rfc4761-compatible command is only used for Huawei and non-Huawei devices to communicate with each other.