Configuring Vpls; Overview; Basic Vpls Architecture - HP FlexNetwork 10500 Series Configuration Manual

Configuring VPLS

Overview

Virtual Private LAN Service (VPLS) delivers a point-to-multipoint L2VPN service over an MPLS or IP
backbone. The provider backbone emulates a switch to connect all geographically dispersed sites of
each customer network. The backbone is transparent to the customer sites. The sites can
communicate with each other as if they were on the same LAN.

Basic VPLS architecture

Figure 97 Basic VPLS architecture
Site 1
VPN 1
Site 4
VPN 2
As shown in
•
CE—A customer edge device is directly connected to the service provider network.
•
PE—A provider edge device connects one or more CEs to the service provider network. A PE
implements VPN access by mapping and forwarding packets between private networks and
public network tunnels. A PE can be a UPE or NPE in a hierarchical VPLS.
•
AC—An attachment circuit, physical or virtual, connects a CE and a PE, such as an Ethernet
link or a VLAN.
•
PW—A pseudowire is a bidirectional virtual connection between two PEs. An MPLS PW
consists of two unidirectional MPLS LSPs in opposite directions.
•
Tunnel—A tunnel can be an LSP tunnel, an MPLS TE tunnel, or a GRE tunnel. It carries one or
more PWs over an IP/MPLS backbone. If a PW is carried on an LSP or MPLS TE tunnel, each
packet on the PW contains two labels. The inner label is the PW label, which identifies the PW
and ensures that the packet is forwarded to the correct VSI. The outer label is the public LSP or
MPLS TE tunnel label, which ensures that the packet is correctly forwarded to the remote PE.
•
VPLS instance—A customer network might contain multiple geographically dispersed sites
(such as site 1 and site 3 in
CE 1
PE 1
AC
PW
AC
PE 4
CE 4
Figure 97, the VPLS architecture mainly includes the following components:
Figure
MPLS or IP backbone
PE 2
PW
Tunnel
PW PW
PW
Tunnel
PE 3
97.) The service provider uses VPLS to connect all the sites
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Site 2
VPN 2
CE 2
AC
PW
Site 3
AC
VPN 1
CE 3