Gang,
The verdict on this is out! Turns out the SIM cards work just as they would at home! I've verified this physically.....down to the IP addresses assigned to them!
I had consulted 2 other friends in 'knowledge street' and got these verbatim responses that may be of interest to some members...
=============Knowledge Street1===============
The APN is only known in your home network.
The serving SGSN, visiting SGSN has to connect to your home APN DNS to resolve the APN so as to get which GGSN to create your session so as to obtain IP services. Once the request is received by your home GGSN, the rest should just flow: IP address, billing, etc
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=============Knowledge Street2===============
When you roam you will be attached to the SGSN in the foreign country, but the routing shall be done on your home GGSN; meaning that you will have an IP from the range provided in the roaming country
Before attaching to the foreign SGSN, the foreign network does a check with your home network - subscriber validation.
Since the routing shall point to your home GGSN which basically routes your APN range of IP's accordingly, you should be routed as if you were at home... also depends on the "APN related priviledges"
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Now we know. :-) :-)
Tony.