Pocket PC using .NET compact framework fails to connect to Web Service

[Duff]

Our application, built using the .NET Compact Framework, is running on
a Symbol handheld (Windows Mobile 2003). It is supposed to call an
intranet web service on a computer in the same subnet. We are using a
DLink router with fixed IP addresses. We can successfully access and
run the web service without error from IE on the local machine where
the web service is running, and from any other computer in the internal
network. The web service has run successfully several times from the
handheld device.

However, now it will no longer run at all from the handheld device and
we are not able to identify what has changed to make it cease to
function. We now get a Web Exception error message and if we dig deep
enough into the exception in the MS Visual Studio "Watch" window under
debug mode, we can see that the return error is a "GATEWAY TIMEOUT"
error. From Internet Explorer on the handheld device we get the message
"[code = GATEWAY_TIMEOUT] a gateway timeout occurred. The server is
unreachable. Retry the request."

It appears that the issue is between the handheld and the gateway
router. We have no filters set up on the firewall on the router that
would prevent the handheld from accessing. The handheld is definitely
calling the correct IP address for the web service, it just cannot
connect. Any ideas?

 

[Guest]

Can you access your web server from PIE on the device?

 

[Duff]

No, we cannot access the web server, we get the exact same error
message when we attempt to access the default.htm in the web server
root.

 

[Duff]

We found the issue. The Symbol hand held inadvertantly had the network
connection type reset to "proxy server". We think that the previous
(working) network connection got overwritten in a session of Active
Sync (on a different desktop machine, where the hand held connection
type was configured as "Standard" instead of "Guest"). So be cautious
with Active Sync sessions when troubleshooting access to web services!
With the network connection type restored on the hand held, we can
again access the web service.