The service numbers (codes) have nothing to do with specific handsets... and everything to do with 3GPP standards. |
It appears that I was a bit trigger happy and submitted prematurely - and then editing failed with an error.
To continue...
The service code is just a phone number that initiates a GPRS session.
To talk across the radio network through to the Internet network - GPRS "tunnels" via what is called Packet Data Protocol (PDP) contexts. Each PDP context is effectively a communication channel and modems/phones may support one or more PDP contexts. Most modems/phones will have default PDP contexts set which can be modified and displayed with AT commands. i.e. AT+CGDCONT=1 and AT+CGDCONT? and AT+CGDCONT=?
The last digit then tells the phone which PDP context you want to use.
*99# Dials the default PDP context
*99***1# Dials the PDP context in memory location 1
*99***2# Dials the PDP context in memory location 2
etc...
Different phones allow different numbers of PDP contexts. Nokia's typically allow 2; whereas, Ericsson's typically allow 10.