boosacnoodle:

 

None of the above comments are quite correct. Every other NZ carrier - except 2degrees - follows the GSMA spec for what the format of a VoLTE server's domain name should look like. Because of this non-compliance, every phone model that wishes to use the 2degrees network needs to be specifically configured to use their custom VoLTE server name. It's not immediately clear why 2degrees made this choice but regardless it has the practical effect of blocking every phone that they (2degrees) have not certified from using their VoLTE services. If 2degrees were to simply set up the default VoLTE server domain name with GSMA it's more likely than not that a bunch more phones would work.

 

Thank you for a truly helpful reply, it seems a rare thing these days, so much appreciated. Its good to understand that nuance. I'm just pleased to be able to use a perfectly good phone to its full potential so full marks to one.nz