L2Tp Over Mpls To Virtual Routing And Forwarding Instance - Cisco 10000-2P2-2DC Software Configuration Manual

Broadband Architecture Models
Figure 1-5
Client
In this model, the Cisco 10000 series router acts as the LNS with VRF 1 and VRF 2 configured on the
router. PPPoX sessions are placed in an L2TP tunnel and terminated at the LNS where they are placed
in the appropriate VRF.

L2TP over MPLS to Virtual Routing and Forwarding Instance

Figure 1-6
LNS provider.
Figure 1-6 L2TP over MPLS to VRF Architectural Model
Subscribers
Access network
(ATM or Ethernet)
CPE
The LNS encapsulates the PPP in L2TP sessions in IP packets and forwards them to the retail LNS
providers, placing the sessions for each provider in separate VRFs.
Cisco 10000 Series Router Software Configuration Guide
1-6
L2TP to VRF Architectural Model
DSL
PPPoX
shows PPP in L2TP tunneled traffic transported over an MPLS tag interface to the wholesale
LAC
MPLS
transport
network
PPP in L2TP sessions.
Note L2TP tunnel traffic
Chapter 1 Broadband Aggregation and Leased-Line Overview
AAA server
VRF 1
LNS
(home gateway) Cisco 10000
IP network
VRF 2
PPP
L2TP tunnel
Wholesale LNS
provider
Not a tag
interface
Tag interface
is in global VRF
Each provider in
a different VRF.
NSP NSP
LNS
AAA, DHCP
servers
NSP NSP
Retail LNS
providers
Provider 1
Provider 2
Provider n
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