Alcatel-Lucent 6850-48 Guida Di Rete

Configuring VPLS

VPLS Overview

OmniSwitch AOS Release 6 Network Configuration Guide

page 11-9

The fact that there is always a full mesh of PWs between the PE devices ensures that every destination 
within the VPLS will be reached by a broadcast packet. 

This implementation of MPLS-based VPLS makes use of a service model architecture. A service is a 
globally unique entity that refers to a type of connectivity service for either Internet or VPN connectivity. 
Each service is uniquely identified by a service ID within a service area. 

The following logical service entities are used to construct a service:

• Customers. The terms customer and subscribers are synonymous. An account is created for each 

customer and assigned an ID. The customer ID is required and associated with the service at the time 
the service is created. 

• Service Access Point (SAP)—A SAP is associated with a service ID, access ports, and an encapsula-

tion value used to classify customer traffic. The SAP binds access ports and customer traffic received 
on those ports to the service. 

• Service Distribution Points (SDPs). A SDP provides a logical point at which customer traffic is 

directed from one PE to another PE through a one-way service tunnel. SDPs are used to set up distrib-
uted services, which consist of at least one SAP on a local node, one SAP on a remote node, and an 
SDP binding the service to the service tunnel. 

The following illustration shows how the above components are used to tunnel customer traffic through a 
service provider network:

In the above diagram:

• SDP1 is setup from PE1 to PE2 and SDP2 is setup from PE2 to PE1. 

• An LSP tunnel is setup for the SDP using the far end system IP address (Loopback0 IP Address) of the 

PEs. This forms the basis for setting up the services (VPLS instances).