We are in the process of enabling site to site VPN encryption between Cisco 7200 (central site) and 3700 (branch site).
We are using GRE/IPSEC tunnels, we are using comp-lzs in our transform sets to take care of compressing.
Our sites has low speed links (64 and 128 kbps), before enabling the GRE/IPSEC tunnels, we were using compress stac on our serial links and it was very effective and almost brought the traffic to half its size.
The problem is that the comp-lzs compression within the transform set seems to be not effective, as once we enable the GRE/IPSEC tunnels the utilization on the serial links reaches almost 100%.
Do you have any hints that would make the comp-lzs compression effective.
Thanks in advance