Cisco IOS Cookbook, 2nd Edition

Compressing Frame Relay Data with Maps

Problem

You want to configure your router to do Frame Relay compression with map statements.

Solution

The same Frame Relay compression options that we discussed for subinterfaces are also available with map statements. You can turn on FRF.9 compression by simply adding a few additional keywords to the frame-relay map statement as follows:

Central#configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Central(config)#interface Serial0
Central(config-if)#description Frame Relay to branches
Central(config-if)#ip address 192.168.1.1 255.255.255.0
Central(config-if)#encapsulation frame-relay
Central(config-if)#frame-relay map ip 192.168.1.10 101 payload-compression frf9 stac
Central(config-if)#exit
Central(config)#end
Central#

Or you can opt to use Cisco’s proprietary packet-by-packet compression instead:

Central#configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Central(config)#interface Serial0
Central(config-if)#description Frame Relay to branches
Central(config-if)#ip address 192.168.1.1 255.255.255.0
Central(config-if)#encapsulation frame-relay
Central(config-if)#frame-relay map ip 192.168.1.10 101 payload-compression packet-by-packet
Central(config-if)#exit
Central(config)#end
Central#

The map configuration also supports TCP header compression:

Central#configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Central(config)#interface Serial0
Central(config-if)#description ...