Question : Problem: wireless connection too slow when try to connect to vpn

I have a wireless router WRT54G and a thinkpad T42 with FC4, connection is ok, but when I try to connect to a vpn, it loses packages.

I think that is a MTU problem, but I dont know how to set it.

Thanks.

Answer : Problem: wireless connection too slow when try to connect to vpn

MTU size can definitely be an issue. However if you are connecting wirelessly, try a wired connection, try a wired connection and see if there is some improvement. The encryption associated with wireless often seems to interfere with the VPN encryption. To adjust the MTU size, have a look at the following links:
http://www.dslreports.com/faq/7752
http://www.dslreports.com/faq/5793