Cisco Systems 10000 Network Router User Manual


 
20-31
Cisco 10000 Series Router Software Configuration Guide
OL-2226-23
Chapter 20 Configuring L2 Virtual Private Networks
Configuration Tasks for L2VPN
DLCI-to-DLCI Connections
If DLCI-to-DLCI connections are configured, LMI runs locally on the Frame Relay ports between the
PE and CE devices.
CE1 sends an active status to PE1 if the PVC for CE1 is available. If CE1 is a switch, LMI checks
that the PVC is available from CE1 to the user device attached to CE1.
PE1 sends an active status to CE1 if the following conditions are met:
A PVC for PE1 is available.
PE1 received an MPLS label from the remote PE router.
An MPLS tunnel label exists between PE1 and the remote PE router.
For DTE/DCE configurations, the following LMI behavior exists:
The Frame Relay device accessing the network (DTE) does not report PVC status. Only the network
device (DCE) or NNI can report status. Therefore, if a problem exists on the DTE side, the DCE is not
aware of the problem.
Port-to-Port Connections
If port-to-port connections are configured, the PE routers do not participate in the LMI status-checking
procedures. LMI operates between the CE routers only. The CE routers must be configured as DCE-DTE
or NNI-NNI.
For information about LMI, including configuration instructions, see the “Configuring the LMI” section
of the Configuring Frame Relay document.
Configuring Frame Relay-to-Frame Relay Local Switching
Frame Relay switching is a means of switching packets based upon the data link connection identifier
(DLCI), which can be looked upon as the Frame Relay equivalent of a MAC address. You perform the
switching by configuring your router or access server as a Frame Relay network. There are two parts to
a Frame Relay network: the Frame Relay data terminal equipment (DTE) (the router or access server)
and the Frame Relay data communications equipment (DCE) switch.
Local switching allows you to switch Layer 2 data between two interfaces of the same type for example,
ATM-to-ATM, or Frame-Relay-to-Frame-Relay.
For background information about Frame-Relay-to-Frame-Relay Local Switching, see the Distributed
Frame Relay Switching feature guide.
You can switch between virtual circuits on the same port, as detailed in the “Configuring Frame Relay
Same-Port Switching” section on page 20-33.
The following channelized line cards are supported for the Cisco 10000 series routers:
1-port channelized OC-12/STM-4
4-port channelized OC-3/STM-1
6-port channelized T3
24-port channelized E1/T1
The following packet over SONET line cards are supported for the Cisco 10000 series routers:
1-port OC-12 Packet over SONET
1-port OC-48/STM-16 Packet over SONET
6-port OC-3/STM-1 Packet over SONET