I know that an unlocked AT&T iPhone can use in Europe and Asia's GSM network.
I have 2 questions:
(1) After Verizon unlocks my iPhone 4S, can I use it in Europe's any GSM network?
(2) After I fulfill my contract, can my unlocked Verzion iPhone 4S uses freely in Europe and Asia?
No you can not use a CDMA version on another network only because the device doesn't have a dedicated GSM radio to be programmed to the network.
I was under the impression that Verizon's iPhone 4S was a global phone with a GSM radio which can be used on GSM networks outside the US. Furthermore, if it is unlocked it can use a local sim card in other countries.
After reading this article I stand corrected... http://news.cnet.com/8301-1035_3-57495076-94/why-you-cant-take-your-unlocked-iphone-4s-to-another-u....
It appears that it can be done only on non US carriers..