3com S7906E Installationsanweisungen
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MPLS L2VPN Configuration
When configuring MPLS L2VPN, go to these sections for information you are interested in:
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The term router in this document refers to a router in a generic sense or a Layer 3 switch.
MPLS L2VPN Overview
This section covers these topics:
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Introduction to MPLS L2VPN
Traditional VPN
Traditional VPNs based on Asynchronous Transfer Mode (ATM) or Frame Relay (FR) are quite popular.
They share the network infrastructure of carriers. However, they have some inherent disadvantages:
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Dependence on dedicated media: To provide both ATM-based and FR-based VPN services,
carriers must establish two separate infrastructures across the whole service scope, one ATM
infrastructure and one FR infrastructure. Apparently, the cost is very high and the infrastructures
are not utilized efficiently.
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Complicated deployment: To add a site to an existing VPN, you have to modify the configurations
of all edge nodes connected with the VPN site.
MPLS L2VPN is developed as a solution to address the above disadvantages.
MPLS L2VPN
MPLS L2VPN provides Layer 2 VPN services on the MPLS network. It allows carriers to establish
L2VPNs on different data link layer protocols, including ATM, FR, VLAN, Ethernet and PPP.