QOS Payload Compression on Serial Links

Payload Compression on Serial Links



Data compression:- Hardware and Software
compressions. 

Software compression:- CPU-intensive or Memory-intensive.

Stacker Compression
Stacker compression is based on the Lempel-Ziv compression algorithm. The Stacker algorithm uses an encoded dictionary that replaces a continuous stream of characters with codes. Stacker compression is more CPU-intensive and less memory-intensive. The Stacker method is the most versatile, because it runs on any supported point-to-point layer-2 encapsulation.
Predictor Compression
The Predictor compression algorithm tries to predict the next sequence of characters in a data stream by using an index to look up a sequence in the compression dictionary. The compression ratio obtained using predictor is not as good as other compression algorithms, but it remains one of the fastest algorithms available. Predictor is more memory-intensive and less CPU-intensive.
Predictor only supports PPP and LAPB.





R2 Config

interface Serial1/0
 ip address 23.1.1.2 255.255.255.0
 compress stac
 serial restart-delay 0
end

R3 Config

interface Serial1/0
 ip address 23.1.1.3 255.255.255.0
 compress stac
 serial restart-delay 0
end







Now on R2 we will change the encap to ppp and see the options



R2 Config

interface Serial1/0
 ip address 23.1.1.2 255.255.255.0
 encapsulation ppp
 compress predictor
 serial restart-delay 0

R3 Config

interface Serial1/0
 ip address 23.1.1.3 255.255.255.0
 encapsulation ppp
 compress predictor
 serial restart-delay 0
end