How to send receive data/sms from GPRS Modem?

Question

Hi,
I need to send receive data/sms from my GPRS/GSM modem. I need to communicate from my modem with several devices over GPRS.
Am I suppose to use TCP Listener and TCP Client classes of C# for this? If yes, then do I need to have a static IP at my modem side to let devices always communicate on that particular address?
Please just guide me with little description or tell me about any library already available for it.
Thank you

Answer 1

you most first  Learing AT Command ,for Working with any Modems

1. http://en.wikipedia.org/wiki/Hayes_command_set
2. http://www.rfsolutions.co.uk/acatalog/AT_cmd-GPRS_User_Guide.pdf
   

see this page
i hope it could be helpfull for you 

http://www.activexperts.com/activcomport/howto/vcnet/