How do I listen for incoming UDP socket connections?

AT#UDPSERV=x.x.x.x (x.x.x.x = the IP address of the incoming client - use "255.255.255.255" if you want to allow any IP addresses to connect)
AT#UDPPORT=n (n = the port in which the stack will listen for incoming connections)

After a GPRS connection has been established using the‘AT#CONNECTIONSTART’ command, use the command ‘AT#LUDPSTART’ to set the stack into listening mode. ‘AT#LUDPSTOP’ will stop the listening mode.

The‘AT#LUDPSTART’ command will have to be issued after every connection if you want the stack to keep listening.