(this is the slightly edited response by me).

Hi, Mike.

You're going to have a relatively hard time troubleshooting this from the (source) side of things. There are a couple of possibilities - one is that it is a problem in (destination). The other is that there is a problem in (source), or someplace between (source) and (destination).

If the problem is with (destination), then that should be readily apparent if you run Ping Plotter in (destination) and have a look at the results there. You should see packet loss near hop 1 or hop 2 there - and that packet loss (and latency spike) will carry on through the rest of the route. Ideally, you'd trace from (destination) to (source), but if you're constantly using a VPN, this might be impossible because of the way your VPN software routes. You *should* be able to trace to the IP address of your VPN server in (source), though - which is just as good as any other address in your physical building (even if it's a different computer than you normally use Ping Plotter from).

If the problem is in (source), then this is because of asynchronous routing - which is a bit harder to diagnose, but if you have control of both ends of the connection (which it sounds like you do), then you'll be able to diagnose.

We had a good discussion on asynchronous routing here:

http://www.pingplotter.com/forums/showflat.php?Board=Support&Number=731

(note that the link to ispworld no longer works, and I've not yet found a new source for this information).

If you run a Ping Plotter trace from (destination) to (source) and send me that data, then I'll be happy to help you diagnose the location of the problem. Note that we will need to have at least one period of problems to do a good diagnosis. Ideally, you'd be running Ping Plotter from both directions so we'd get a good set of data to know the entire route - from you (in (source)), to (destination), and then back again.

The *return* route can definitely cause you pains from only one of your remote sites and not others - because your ISP might be peering with different ISPs and just one of those is behaving poorly.

Also, note that you won't be able to trace from (source) to the gateway in (destination) - as the gateway IP address you gave me isn't internet routable.

- Pete