We have a lan-lan VPN set up between two sites, with a 2800 at one site and a 2820 at the other. The site with the 2820 has just been upgraded to BT's 40Mb down / 8Mb up service. Trying (from the 2800's end) to access files stored on a server at the 2820's site results in the following speeds:

1. over public internet, using http : ~1MByte / sec
2. over VPN, using SMB protocol : ~100-250KB / sec
3. Over VPN using http: ~100-250KB/sec
4. switching off the lan-lan VPN and using Microsoft's VPN client on windows xp, and SMB Protocol: ~300-400KB/sec
5. As 4, but using http: ~300-400Kb/sec

Now what I don't understand is this slowdown when using either lan-lan (i.e. Draytek's VPN at both ends), and slightly less of a slowdown when using Draytek's VPN at the 2820 end only.

Clearly, the server we are accessing, and the broadband networks are capable of pushing around a megabyte per second as seen by (1) above.

It looks very much like the Draytek VPN processor in the 2820 is causing a bottleneck.

Does anyone know if there's something that can be done about this? obviously with broadband speeds being generally lower than that, most people would never notice any bottleneck.