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https://jmcomms.com/2015/12/16/on-ee-remember-the-volte-settings-that-the-iphone-6-got-recently-well-you-might-just-be-able-to-use-it-right-now/
[Updated] On EE? Remember the VoLTE settings that the iPhone 6 got recently? Well, you might just be able to use it right now!