I have a client with 4 XP SP3 thin clients (HP t5740) that act as shipping stations. They have a scale hooked up to the serial port used to weigh packages. They RDP to a 2008 r2 server (with all the updates).
Now, 2 of these thin clients are on the lan, and work just fine. The other two come across a wan/vpn connection and the only thing that doesnt work is the serial port redirection.
The funny thing is that they (the wan and lan tc's) worked when they connected to a 2003 TS box (which we have not been able to decom. because of this). All 4 thin clients are identical, have the latest firmware, etc etc. The connection is a 10mbps down/2mbps up and we're using the same username to test all of them. The only difference is the wan.
Is there some sort of latency requirement for serial port redirection or anything else causing this, usually in the past with issues like this it either works or it doesn't. I've not had some working and some not working like this. Thanks for any help!