Slow browsing and file opening in Windows via a VPN
Posted on 2011-10-05
I am assisting a friend with their small business network / office move from a formal office to a virtual office where everyone works from their home. They purchased and installed Sonicwall TZ-210s in everyone's home. The Sonicwalls have a VPN connection to the small business server located in one employee's home. The VPN tunnels are working great - with one exception. Whenever any of the employees try to browse a folder or open a file on a mapped drive, it takes an extraordinary amount of time. (The employee with the server in their home is the obvious exception; they have no folder/file issues.) By "extraordinary", I'm talking a 3-5 minute wait, or longer. Now I realize we are at the mercy of ISP bandwidth, but 3-5 minutes seems REALLY slow to me. A copy of a 25k file from the server to one of the client PC desktops took 3 minutes. One particular employee has both a Mac and a PC at their home. The Mac can view folder contents and open files from the server in seconds. The PC takes 3-5 minutes. That test told me that the Sonicwall is not the culprit. So I'm guessing that it has something to do with the Windows PCs and the server...but what? Incidentally, the PCs that are being used were the same client PCs that were in the original office. Is there something I should be doing to change them to VPN clients?
Some pertinent information:
The ISP connection at the server is 60 Mbps DOWN and 10 Mbps UP. This has been verified by using various speed testing web sites.
The ISP connections at all other locations are no less than 22 Mbps DOWN and 5 Mbps UP.
The CPU utilization of the Sonicwall at the server location is around 10%. No errors in the log.
All client PCs are running Windows XP SP 2.
The server is running Microsoft SBS 2008.
If I map a drive on a PC in my office (in a different domain), I can connect to their server and browse folders and open files in seconds. (I also have a Sonicwall TZ210 on my office. I have Windows 7 installed.)
What do you experts suggest?