T-Mobile won't support IPv4 since a few years ago.

 T-Mobile won't support IPv4 since a few years ago.

a customer, went to the CES show to demo the devices, but they use the 'T-Mobile' prepaid card and they can not obtain the IPv4 address. check a lot of forums, most customers can not use IPv4.

Better to suggest the user buy the AT&T prepaid card if they need to via IPv4 to function devices.

2023 一個客人去CES demo 5G devices, 他買了 T-Mobile 的預付卡，結果拿不到IPv4 的address, 
查了一堆美國的論壇才發現，T-Mo 很多年前就開始不支援IPv4, 僅有少數的APN有支援IPv4.

看起來未來也不打算要支援IPv4. 所以IPv6 成為了重點。而客人的軟體也要提醒他們，不要只做IPv4. (在IoT的市場，很多客人是傳統產業的，他們並不了解IPv4 &IPv6的差異)

但這個問題很有趣。