Grandstream GRP2604 Multipurpose keys not provisioned

[JohnS_3CX]

So you provisioned the phone in Local mode, when in fact it is not local since the instance is in EC2, which explains one of the most typical reasons we see BLFs failing to subscribe.

Now you've enabled NAT traversal which is not meant for local connections, basically like running the phone in STUN mode which is not supported. Please note that since this is not a supported network config, and you might face further issues you will have to troubleshoot later. In addition, the custom templates will have to be manually maintained because they will not auto-update when we release new service packs.

If the instance is in EC2, then it is considered remote and the correct solution here would be to install an SBC in the same LAN as the phones, which will connect them up to your instance in a supported manner.
https://www.3cx.com/docs/3cx-tunnel-session-border-controller/

 

[evanlonden]

Hi John, I agree. As the setup I have is pretty small with only a few phones of the same brand and model I think I can use the setup I have now without using a SBC. The NAT autodiscovery works pretty well for the moment.