are all iphone 6 gsm and cdma?
No. In the US, the GSM version of the A1549 iPhone 6 is sold unlocked and without a contract on T-Mobile and it does not support CDMA networks. ... Starting on January 6, 2015, Apple also started selling an unlocked version of the A1586 "Global" iPhone 6 in the US, which Apple refers to as the "Unlocked" iPhone 6.