R3303-HP HSR6800 Routers MPLS Configuration Guide

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Advantages of H-VPLS access
• H-VPLS has lower requirements on the multi-tenant unit switch (MTU-s). It has distinct hierarchies
which fulfill definite tasks.
• H-VPLS reduces the logical complexity of the fully meshed network consisting of PEs and the
configuration complexity.
H-VPLS with LSP access
Figure 55 H-VPLS with LSP access
As shown in Figure 55, UPE functions as the MTU-s and establishes only a virtual link U-PW with NPE 1.
It does not establish virtual links with any other peers.
Data forwarding in H-VPLS with LSP access is as follows:
1. Upon receiving a packet from a CE, UPE tags the packet with the MPLS label for the U-PW, namely,
"the multiplex distinguishing flag," and then sends the packet to NPE 1.
2. When receiving the packet, NPE 1 determines which VSI the packet belongs to by the label and,
based on the destination MAC address of the packet, tags the packet with the multiplex
distinguishing flag for the N-PW, and forwards the packet.
3. Upon receiving the packet from the N-PW, NPE 1 tags the packet with the multiplex distinguishing
flag for the U-PW and sends the packet to UPE, which forwards the packet to the CE.
For packets to be exchanged between CE 1 and CE 2, UPE can forward them directly without NPE 1
because it holds the bridging function by itself. For the first packet with an unknown destination MAC
address or a broadcast packet, UPE broadcasts the packet to CE 2 through the bridging function and, at
the same time, forwards it through U-PW to NPE 1, which replicates the packet and sends a copy to each
peer CE.
H-VPLS with QinQ access
Figure 56 H-VPLS with QinQ access