R2511-HP MSR Router Series MPLS Configuration Guide(V5)

Figure 24 VC redundancy protection in an MPLS L2VPN

The MPLS L2VPN determines whether the primary VC fails according to the LDP session status and the

BFD result. The backup VC is used in the following circumstances:

• The tunnel of the primary VC is deleted or no longer meets the tunneling policy, causing the primary

VC to go down.

• The BFD protocol detects that the primary VC has failed.

• The LDP session between the two endpoint PEs of the primary VC (for example, the LDP session

between PE 1 and PE 2 in Figure 24) goe

s down, causing deletion of the primary VC.

• A VC switchover command is executed.

MPLS L2VPN interworking

CEs might connect to PEs through various types of links, such as ATM, FR, HDLC, Ethernet, and PPP. An

MPLS L2VPN can connect such CEs and allow them to communicate. This feature is referred to as "MPLS

L2VPN interworking."

MPLS L2VPN supports Ethernet interworking and IP interworking modes. Only CCC, SVC, and Martini

VCs created on Layer 3 interfaces support the interworking feature.

Figure 25 Ethernet to PPP interworking (Martini mode)