Specifications

CHAPTER

24-1

Cisco MWR 2941 Mobile Wireless Edge Router Release 3.5 Software Configuration Guide, Cisco IOS Release 15.1(3)MR

OL-26895-01

Configuring MPLS VPNs

A Virtual Private Network (VPN) is an IP-based network that delivers private network services over a

public infrastructure. VPNs allow you to create a set of sites that can communicate privately over the

Internet or other public or private networks.

The following sections describe how to configure MPLS VPNs on the Cisco MWR 2941:

• Understanding MPLS VPNs

• Configuring MPLS VPNs

• Sample MPLS VPN Configuration

Understanding MPLS VPNs

A conventional VPN consists of a full mesh of tunnels or permanent virtual circuits (PVCs) connecting

all of the sites within the VPN. This type of VPN requires changes to each edge device in the VPN in

order to add a new site. MPLS VPNs, also known as Layer 3 VPNs, are easier to manage and expand

than conventional VPNs because they use layer 3 communication protocols and are based on a peer

model. The peer model enables the service provider and customer to exchange Layer 3 routing

information, enabling service providers to relay data between customer sites without customer

involvement. The peer model also provides improved security of data transmission between VPN sites

because data is isolated between improves security between VPN sites.

The Cisco MWR 2941 supports the following MPLS VPN types:

• Basic Layer 3 VPN—Provides a VPN private tunnel connection between customer edge (CE)

devices in the service provider network. The provider edge (PE) router uses Multiprotocol Border

Gateway Protocol (MP-BGP) to distribute VPN routes and MPLS Label Distribution Protocol

(LDP) to distribute Interior Gateway Protocol (IGP) labels to the next-hop PE router.

• MPLS Carrier Supporting Carrier (CSC) VPN—Enables an MPLS VPN-based service provider to

allow other service providers to use a segment of its backbone network. MPLS CSC VPNs use

MPLS LDP to distribute MPLS labels and IGP to distribute routes.

• Inter-Autonomous System (AS) VPN—An inter-AS VPN allows service providers running separate

networks to jointly offer MPLS VPN services to the same end customer; an inter-AS VPN can begin

at one customer site and traverse multiple service provider backbones before arriving at another

customer site.