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> Cellular carriers have special handling for APNS and GCM, for example Would you have any extra info on this? Thanks!

• smileybarry 3y ago
  Not off the top of my head, but I remember the iPhone in its early years required specific carrier support because of that permanent APNS connection. Can't find a source for this now but I remember that being one of the reasons that iPhone 2G/3G/3GS wouldn't work (well) on other carriers even after SIM unlocking. I assume nowadays it's more to do with GCNAT pruning connections to APNS/GCM less heavily than other "regular" connections (which is doable given that APNS has specific ports[1]), or cell carriers having different routing & handling for push notifications IPs, but that's just speculation. 1: https://support.apple.com/en-us/102266 https://support.apple.com/en-us/102266