3Com 8807 - Mpls Vll; MPLS L2 VPN Overview

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MPLS VLL
MPLS L2VPN Overview
Introduction to MPLS
L2VPN
MPLS L2VPN provides MPLS network-based Layer 2 VPN services. For users, an
MPLS L2VPN is a Layer 2 switched network, through which Layer 2 connections
can be established between network nodes.
Figure 146 MPLS L2VPN
MPLS L2VPN has the following advantages:
■ Multiple network layer protocols supported, such as IP, IPv6, IPX, and SNA.
■ Powerful extensibility. MPLS L2VPN only establishes Layer 2 connections, rather
than imports and manages the routing information. This eases work load of PE
(provider edge) devices and the entire SP (service provider) network remarkably
and thus enables SPs to provide more VPNs and accommodate more users.
■ Reliability and privacy of user routes. As no user routing information is
imported, there is no need for MPLS L2VPN to obtain and process the
information, ensuring the privacy of user routes.
Figure 147 illustrates the structure of an MPLS L2VPN packet.
VPN A
VPN A
VPN B
VPN B
CE
CE
CE
CE
PE
PE
PE
VC
VC
LSP
P
P
VPN A
VPN A
VPN B
VPN B
CE
CE
CE
CE
PE
PE
PE
VC
VC
LSP
P
P