I have a pix 506e at a remote location terminating a VPN tunnel to a Cisco concentrator 3015 which sits at our corp. offices. The site uses split tunneling so it only accesses the site across the tunnel for corporate traffic. They connect to a terminal emulating program, oracle through a web browser and e-mail via SMTP through the tunnel.
Periodically through out the day the remote end will experience extreme slowness. When I ping across the tunnel the response is 300ms or higher. If I ping the outside interface to check the internet side it pings at 83ms. Since the internet side is stable at 83ms it can't be the internet causing the slow down. I have had every single user in the remote location shutdown all computers and printers but it does not fix the problem they still run at 300ms. I have enabled logging to debugging, installed an SNMP monitor and watch the connections. I do not see anything out of the ordinary and I can't seem to find what is causing the tunnel to slow down to that extreme.