Delayed response time from server

I'm hoping this is the correct forum for this question

I am very new to network management. I am responsible for a small
multi-location network. In our main office location I have 3 servers all
running Win2003 SP2 standard. One of the servers acts as the main domain
controller running DNS and AD, it also has SQL 2005 installed. One server is
just a datawarehouse, and the back up DC. The 3rd server runs our Terminal
Server. I have 3 locations that connect to this network via WAN using a VPN
connection via a Sonicwall appliance. My client workstations are either XP
pro SP2 or simply a Wyse Thin Client. The client workstations connect via
RDP to the terminal server to run an application. The application saves data
to the Sequal server.

The response time to the client workstations is unacceptably slow. Users
type data into the app and can type a whole line of text prior to it
appearing on their screen. Opening files is also a time consuming process.

I have run a ping command at one of the remote locations and get a norma
(15-16ms) response when pinging the domain controller server. However when i
ping the Terminal server - I get response times varying from 100-627ms. The
fact that the response is "normal" when pining one server, and long on the
other, makes me believe that this may not be a problem with the network
connectivity per se.

I am at a loss as to what to try next Any imput or suggestions would be
greatly appreciated.

Thanks

Hi,
i cant offer that much.
You may ping your different server from a PC on the location where all the
server sits, yust to see whether the differences in response time are the
same / still exists.
If , it would hint me to the TCP/IP protocol stack of the terminal server. I
would first just compare that one with the others (output of ipconfig).
From the remote location you could test your routing with pathping /
tracert.
jk