Point-to-point software compression on serial interfaces can be configured after PPP encapsulation is enabled. Because this option invokes a software compression process, it can affect system performance. If the traffic already consists of compressed files, such as .zip, .tar, or .mpeg, do not use this option. The figure shows the command syntax for the compress command.
To configure compression over PPP, enter the following commands:
R3(config)# interface serial 0/0/0
R3(config-if)# encapsulation ppp
R3(config-if)# compress [ predictor | stac ]