Question: are all iphone 6s cdma and gsm?
Answer: Unlocked iPhone 6S: A1633 vs 1688 Both the A1633 and A1688 work well on any US carrier, including Verizon, AT&T, T-Mobile and Sprint. ... The A1688 is for GSM and CDMA, sold as the carrier model for Verizon, T-Mobile and Sprint.