3CX Direct SIP Android Application

[Anguskong]

I have Direct SIP setup for External networks, my system is currently hosted in Azure... so it's a must as I am just a home user and exploring 3CX. However I am having an issue specifically with the Android version of the 3CX application. Apple I can make work with a bit of a workaround... detailed shortly.

Problem:
I could originally not dial from one extension to another, thinking it was a 3CX configuration I made in error. After logging into the webclient and being able to dial extensions to the phone apps from within my home without issue I figured it was an authentication issue.

Identified Issue?:
Is it possible that the 3CX phone application cannot resolve the External PBX IP to the correct IP? When I ping from my internal network to my external PBX FQDN it returns the correct IP address.

Workaround:
On Apple iOS I can manually set the local account settings where Android I cannot.

• Under Settings -> Accounts -> <Account Name> , I manually set the Local PBX IP to the Public IP address of the server

Because of this I can call outbound from my Apple iOS devices to other extensions configured (to include the problem Android Devices) and out the main Trunk, as I would expect. So the issue seems to be DNS resolution on the 3CX phone app?

 

[Saqqara]

Mobile apps do not use direct sip, it uses the 3cx tunnel port on 5090 (tcp / and udp) and the https port

under options for each extension, have you unticked ‘allow tunne , sbcl’ (can not remember the full description)

 

[Anguskong]

Yes, that option is left unchecked. As the same extensions works from the Apple device. It really does seem to be the Android app from my troubleshooting, especially how it's handling DNS? It's like it can't resolves the full FQDN to an IP address.

 

[leejor]

Could the issue be, that because both devices are behind the same router (I'm assuming), and if they are not set to use the 3CX tunnel, you have not assigned each device a unique local SIP port?

 

[Anguskong]

They are using the 3cx tunnel, at least I assume as both applications are at default settings. I am able to call from one apple device to another apple (and Android) device behind the same router.

 

[Anguskong]

I was unable to get this to work, but something was really odd with the Local/Public DNS resolution. Should be noted I was using PBXEXPRESS in Azure.

I have since setup a new instance within my homelab and that is working all as expected!