How can I tell if compression is effective on an HDLC T-1 line?

[flynch]

How can I tell if compression is effective on an HDLC T-1 line? Cisco recommends that compression not be used if the majority of data is already compressed(by the application). Do the compression statistics tell me anything about the effectiveness of compression?

[d.bhattacharjee]

T1 line has a bandwidth of 1.5Megs, with compression enabled (payload or tcp header) you should be able to send in more that 1.5Megs per sec. That would prove the compression being effective.

Interpretting the sh compress output..must lead to the compression ration to be more than 1. otherwise the router is expanding data rather than compressing!

check the url for interpreting sh compress...

http://www.cisco.com/en/US/tech/tk13/tk504/technologies_tech_note09186a0080093f77.shtml

also check this WAN Compression FAQ

http://www.cisco.com/en/US/tech/tk13/tk504/technologies_q_and_a_item09186a0080093c04.shtml#25

Hope that helps.

[rjackson]

I thouht I was finally going to learn something about this but the links are no good.