We have one office and one construction site. The construction site connects to the office through site to site VPN but the applications used on the construction site goes very slow!
There is a Cisco asa 5505 at the construction site and a Pix Version 6.3(5) at the office. The ISP line is 100Mbit fiber at both locations. Speedcheck shows 80 mbit/s at the construction site and when my constructors pings the local servers the response time is about 10 ms. There is only small amounts of data that is going through the tunnel.
Are there some limitations in the site to site software that is causing this? It is strange that it is so slow when speedcheck shows good result and ping shows good result.
This is very likely an MTU issue. You can confirm this by reducing the tcp mss on the ASA and Pix. If you can not do this because it is a global change, modify the MTU on the server itself to something like 1300 (linux it is ifconfig eth0 mtu 1300). If PMTU is enabled, that will likely fix your issue.