HP 10500 SERIES Configuration Manual page 202

Martini MPLS L2VPN
Martini MPLS L2VPN employs two levels of labels to transfer user packets, and uses LDP as the signaling
protocol to distribute the inner VC label.
To exchange VC labels between PEs, Martini extended LDP by adding the VC FEC. The VC FEC contains
the following information:
VC type—Encapsulation type of the VC. For more information, see
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VC ID—Identifier of a VC on a PE.
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The VC type and the VC ID uniquely identify a VC. On a PE, the VC ID uniquely identifies a VC among
the VCs of the same type.
As shown in
are distributed, a VC is set up between the PEs.
Figure 5 Label distribution in Martini mode
Kompella MPLS L2VPN
Kompella MPLS L2VPN employs two levels of labels to transfer user packets, and uses BGP as the
signaling protocol to distribute the inner VC label.
Different from other MPLS L2VPN modes, Kompella introduces the concept of VPN. It allows CEs in the
same VPN to establish a connection. CEs in different VPNs cannot establish a connection.
Kompella MPLS L2VPN has the following basic concepts:
CE ID—Kompella numbers CEs inside a VPN. A CE ID uniquely identifies a CE in a VPN. CEs in
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different VPNs can have the same CE ID.
• Route distinguisher—To distinguish CEs with the same CE ID in different VPNs, Kompella adds an
RD before a CE ID. An RD and a CE ID uniquely identify a CE.
Route target—Kompella uses the BGP route target attribute (also called "VPN target" attribute) to
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identify VPNs to make sure CEs in the same VPN can establish a connection and CEs in different
VPNs cannot.
A PE supports the following types of route target attributes:
Export target attribute—When a PE sends L2VPN information (such as CE ID and RD) to the peer
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PE through a BGP update message, it sets the route target attribute carried in the update message
to export target.
Import target attribute—When a PE receives an update message from the peer PE, it checks the
•
route target attribute in the update message. If the route target value matches an import target on
the PE, the PE accepts the L2VPN information in the update message.
Figure 5, the PEs send a VC FEC and VC label mapping to each other. After the VC labels
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"VC encapsulations types."