Technical information

Table Of Contents
Improved OEM Features
1-4 AT Commands Reference Manual January 31, 2007
TCP/IP
When establishing the TCP/IP connection the G24 can only be the "initiator". The TCP/IP feature
enables the G24 to be a wireless end point for a TCP/IP socket.
Note: The TCP protocol use the value TTL (Time to live) = 64.
Creating TCP/IP Connections
Connection from the G24 to the Web
The following occurs when creating a TCP/IP connection from the G24 to the Web:
1. The G24 connects to the GPRS network and receives an IP address (using the +MIPCALL
command).
2. The G24 opens a TCP/IP stack as one of its "sockets" (it must know the target’s IP address
and port number).
3. Once the connection is established, data is transferred freely in both directions (upload and
download).
Connection with another G24 using the "GPRS Manager"
The following occurs when creating a TCP/IP connection with another G24 using the "GPRS
Manager":
1. The OEM on the target side (server) uses the "GPRS Manager" application. When using this
application the TCP/IP is external to the OEM. (External TCP stack is used).
2. The target side activates the "server application" (The term "server application" means an
application that has the ability to listen on a given IP address and port number).
3. After connecting to the GPRS network, the "server" sends its IP address to the G24 using an
alternative connection (for example, CSD, SMS and so on).
4. The server application listens on a known port, waiting for G24 to connect.
5. The G24 connects to the same GPRS network as the server, and receives an IP address
(using the +MIPCALL command).
6. The G24 initiates a TCP/IP connection with the listening "server". (It knows the IP address
and port number of the server).
7. Once the server is connected, the TCP/IP connection is created and data can be transferred
freely in both directions (upload and download).