at&t use gsm only, what is the exact model of the phone?
samsung s7 SM-G930VL. it uses a sim card that is cdma. can i flash it to gsm?
That looks to be a straight talk model, why don't you just contact AT&T and see if that phone will work on their plan? AT&T does not use CDMA, they use GSM. Verizon and Sprint use CDMA.