What would make a callback request hang?

Question

I am working on a project that uses the asp.net ajax control toolkit and all my callback requests are hanging till the request times out. When I step through the code all my code executes then the hanging occures. Right now I am looking for possible reasons why this might happen.

Answer 1

If the request takes significant time, it is possible that the client-side AJAX request is timing out before your server-side code completes. At that point the client has dropped the connection and the server can no longer communicate with it. Can you look into increasing the timeout value on the client to something really big to eliminate this as a possibility?

Answer 2

Firewall or NAT? Something on the network might be blocking return calls from getting back to you.

Answer 3

Check if the callback address you are providing is valid to the server. For instance, the server may not be able to translate some host name or DNS entry.