VPN performance Issue

[timpotter]

We have a 3005 Concentrator and 17 small office sites with 3002's. They are all DSL connections from 192K - 768K. The problem lies with Exchange performance. At our site with 768K, it takes about 3 minutes to open a 2MB email file. I would expect that to take about 30 seconds or so. Files in the 4-5MB range often hang the computer. Some of the sites have email being delivered down to their PST's so they have no problems. But those sites that have no PSTs are having huge performance issues in Outlook. I don't understand why the connection would be so slow. I also tested over a T1 connection and a 2MB files opened in about 10 seconds. Any thoughts? Ideas?

Thanks,

-Tim

[lrector]

I also have a question in this forum, about the same issues...I have multiple ADSL sites with 1.5m upstream/256k downstream, that exhibit similar performance. I have found the problem appears to lie in the tunnel throughput. I can only see about 300k downstream throughput in any of the connections... I am using 827 routers on my remote end, with 3015 concentrator on headend.. I know that the encapsulatiion type has an effect on performance, as well as the number of tunnels at the headend. I also know that 'hardware' based encryption will enhance performance, as well as increasing your bandwidth at the headend.

[elijah.savage]

I had almost the same issue but it was with 2 3030 load balanced with about 2000 clients. But no hardware clients these were all software client based using 3.6.7 version. Some users were dialup some were dsl some were using frame connections from our remote offices. They could not even open a 300k file without it being very slow or hanging, but after looking this board I saw there were alot of people having this problem and adjusting the MTU fixed it, we found out adjusting all of our clients MTU all the way down to 1265 makes everything run great for dialup and dsl and cable users. Might be something you want to look into.