Question : Tracking down reason for lag

My neighbor and I vpn into the same workplace and we are seeing very different lag times with Windows remote desktop (he has more lag than me).  I will try to lay out everything I know and maybe you guys can help direct me where to look to alleviate the lag we have.

Info:
•      I have cable internet
•      My neighbor has wireless internet (wireless to his house)
•      When I go the various bandwidth testing websites I am getting 350 up/650 down (when VPN’d using)
•      I get 350 up/1024 down at bandwidth testing sites when at my neighbors house (with my same laptop from home) while VPN’d
•      Using Cisco vpn software (required by work)
•      I am behind a wireless router assigning private ips (192.168..)
•      Neighbor is behind a wireless router assigning private IPs as well
•      I always have a pretty good response time with remote desktop when I am at home (almost instantaneous)
•      I usually have bad response time (5 to 10 secs to register a mouse click) when I am at neighbor's but sometimes it is decent (<0.5 sec).  Screen refresh rate isn’t very good either.
•      I am always connecting to the same server with remote desktop
•      At times when my neighbor is experiencing a lot of lag things are always fine at my house (connection is always fine from my house).

What I think is strange is that his connection tests as better than mine but his connection through remote desktop is a lot worse.  Are there better tests I can do?

Settings on the computer can be ruled out i think because i am using the same exact laptop (with no configuration change) for all my tests.

Does anyone have any ideas on what could be causing this behavior and how can I test/verify those ideas?

Answer : Tracking down reason for lag

If you are both connecting to the same location but through different providers, try a few traceroutes and see if there is a difference in hops and see where the latency is. On my network it may only be 9 hops to a remote server in Georgia, where as the guy next door to me is using one of my competitors (such as time warner cable), it may be 15 or visa versa since we have different backbones to the net. As a wireless ISP veteran, I can honestly tell you hard line connections are usually more stable and a bit faster, but we are always more flexible :) We go where copper cant......

traceroute several times from each and see what you get.