l am trying to setup a USSD application working through sockets.

l have no idea where to start, can someone point in the direction.

I think you should start with the documentation from your provider.

Thank you for the reply, l have a general understanding and have written a php script to do the work.My problem comes on troubleshooting the link.If l don't get a response how can l confirm if USSD gateway is not sending back response or l am just not capturing it etc.

If you work with a local server, then you can use a tool like Fiddler to trap incoming/outgoing data. Next to that, add logging to everything you do, whether it's to file or database. If the USSD is not responding, it can be hardware and/or software. They should have a sandbox for you for testing purposes.

Ok thankx let me look for fiddler

Ok after hours and hours of trying l cant get this to work as l want.Someone wrote a python script for the same thing, can you help me translate it to php. Download the code here

I don't know python, and I have no intention to learn. Anyway, just found this code on google. Perhaps it will help.