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Cisco 10000 Series Router Software Configuration Guide
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Chapter 20 Configuring L2 Virtual Private Networks
Configuration Tasks for L2VPN
Configuring Frame Relay over MPLS
Frame Relay over MPLS encapsulates Frame Relay protocol data units (PDUs) in MPLS packets and
forwards them across the MPLS network. For Frame Relay, you can set up data-link connection identifier
(DLCI)-to-DLCI connections or port-to-port connections.
•
With DLCI-to-DLCI connections, the PE routers manipulate the packet by removing headers,
adding labels, and copying control word elements from the header to the PDU.
•
With port-to-port connections, you use HDLC mode to transport the Frame Relay encapsulated
packets. In HDLC mode, the entire HDLC packet is transported. Only the HDLC flags and FCS bits
are removed. The contents of the packet are not used or changed, including the FECN, BECN, and
DE bits.
Note
Frame Relay traffic shaping is not supported with AToM-switched VCs.
You can configure Frame Relay over MPLS in the following ways:
•
Configuring Frame Relay over MPLS with DLCI-to-DLCI Connections, page 20-28
•
Configuring Frame Relay over MPLS with Port-to-Port Connections, page 20-29
•
Enabling Other PE Devices to Transport Frame Relay Packets, page 20-30
Configuring Frame Relay over MPLS with DLCI-to-DLCI Connections
To configure Frame Relay over MPLS with DLCI-to-DLCI connections, enter the following commands
beginning in global configuration mode:
Command
Purpose
Step 1
Router(config)#
frame-relay switching
Enables permanent virtual circuit (PVC) switching on a Frame
Relay device.
Step 2
Router(config)#
interface serial
slot/port
Specifies a serial interface and enters interface configuration
mode.
Step 3
Router(config-if)#
encapsulation
frame-relay
[
cisco
|
ietf
]
Specifies Frame Relay encapsulation for the interface.
You can specify different types of encapsulations. You can set
one interface to Cisco encapsulation and the other interface to
IETF encapsulation.
Step 4
Router(config-if)#
frame-relay intf-type
dce
Specifies that the interface is a DCE switch. You can also
specify the interface to support NNI and DTE connections.
Step 5
Router(config-if)#
exit
Exits from interface configuration mode.