I have Verizon service which is a CDMA system, but I am traveling to Vietnam, and need a GSM phone to use there. I can get a prepaid SIM card to use at almost any shop there.
New unlocked GSM phones are available on Ebay, but they are “AT%T, T-mobile”. Does that mean anything? Does it mean they will only work on the AT&T, T-mobile networks even though they are “unlocked”? If that is not the case, why does the seller advertise them as “AT&T, T-mobile”?
I just want to make sure I don’t get to Vietnam, put a prepaid SIM card into it and it won’t work.
they’re usually listed as “AT&T, T-Mobile” when they can accept a SIM from either carrier and support the frequency bands held by those carriers. There’s no guarantee that a phone which supports those two carriers can be used in other countries operating on different bands. Some phones are “global” which means they do; I had a Verizon Windows Phone a while back (HTC Trophy) which was “global,” it used its CDMA radio here at home on VZW’s network, but came with a Vodafone SIM for use in Europe and elsewhere.
edit: for the phone you linked, these are the supported bands:
GSM850/900/1800/1900MHZ
so you’d need to find out what bands are used where you’re traveling to.