VoIP App for Android

I am looking for a VoIP App for Android. The use case is quite simple. I want to experiment with a PBX with extensions only, no trunk. I realise that without scope for a vendor tie in, this may not be quite the simplest request. Ideally free of course. Any suggestions?

Linphone is free and fine for testing etc.

As a permanent solution, especially with a commercial service provider, I’d be leaning towards the Acrobits stable for their features, especially operating system integration like native push which is awesome.

Thanks. Now to try Linphone on my SIP trunk before I get into the PBX.

In reply to a post by Pheasant:

I’d be leaning towards the Acrobits stable for their features,

I've been using Acrobits Softphone for a couple of years now. Recommended.

Acrobits looks interesting too, as Pheasant says for a permanent solution. The PBX is a very background project at the moment.

Before I went to Acrobits, I think I had Zoiper and Sipdroid. They were OK.

For playing around with a local SIP server, you may be better using one of these rather than Acrobits, because with Acrobits their server needs to be able to register to the SIP server: that means your SIP server needs to have a public IP address and be reachable from outside.

Yup. Definitely not a good idea to expose your Asterisk (or similar box) to the open internet, especially whilst you’re tinkering or getting used to how it all works. Even once setup properly you’d want to make sure it was decently secure. Too many miscreants out there.

In reply to a post by candlerb:

Before I went to Acrobits, I think I had Zoiper and Sipdroid. They were OK.

For playing around with a local SIP server, you may be better using one of these rather than Acrobits, because with Acrobits their server needs to be able to register to the SIP server: that means your SIP server needs to have a public IP address and be reachable from outside.

Thanks for the suggestions.

A bit puzzled by the Acrobits comment. Would an Asterisk box not be a competent SIP server in its own right for a private telephone network, without a connection to any outside server?

You can completely isolate your Asterisk box, but then you can’t run it with Acrobits as it needs to register with your Asterisk box on a publicly available IP to function.

This is the nature of how Acrobits push tech works - it has a constant connection from whatever SIP box it is your connecting to (in this case your own) so that its own servers manage the push notification process with the app on your phone.

It’s not like your Joe Average SIP client - it’s more of a full service - you just don’t notice it.

In reply to a post by Pheasant:

This is the nature of how Acrobits push tech works - it has a constant connection from whatever SIP box it is your connecting to (in this case your own) so that its own servers manage the push notification process with the app on your phone.

You can disable this feature but it is the default.

In reply to a post by jchamier:

In reply to a post by Pheasant:

This is the nature of how Acrobits push tech works - it has a constant connection from whatever SIP box it is your connecting to (in this case your own) so that its own servers manage the push notification process with the app on your phone.

You can disable this feature but it is the default.

So if Acrobits does not have access to its own servers, the push feature does not work. I get that.

But if you disable the push feature, does it become a normal SIP phone, or does it still demand access to its own servers?

And can you get a private phone system by connecting the Acrobits phone to its own servers and letting the acrobits servers seen the PBX extensions on the internet, much like they would see the SIP provider?

In reply to a post by DFScale:

I am looking for a VoIP App for Android. The use case is quite simple. I want to experiment with a PBX with extensions only, no trunk. I realise that without scope for a vendor tie in, this may not be quite the simplest request. Ideally free of course. Any suggestions?

GS Wave (Grandstream Wave) is another Android app you can use for making VOIP calls. It is free to use.

Acrobits connects SIP to the server you define, and optionally has PUSH so if your phone terminates the app an incoming call wakes it up.

In reply to a post by jchamier:

Acrobits connects SIP to the server you define, and optionally has PUSH so if your phone terminates the app an incoming call wakes it up.

But that only works because the SIP client credentials are passed onto Acrobits own server, which holds open a connection to the SIP server.

When I go into sipgate and look at registered devices, I see a registration from "Acrobits SIPIS" from IP address 10.65.x.x: this is not part of my network, it's behind Acrobit's own NAT.

In reply to a post by candlerb:

When I go into sipgate and look at registered devices, I see a registration from "Acrobits SIPIS" from IP address 10.65.x.x: this is not part of my network, it's behind Acrobit's own NAT.

What does it show if you turn off the push setting ?

In the Settings I can chose "incoming calls" either Push, or Standard; and in Standard mode the push options disappear. I get a warning of a battery life impact. With Push enabled I can choose in the options to simulate NAT or not.

In reply to a post by jchamier:

What does it show if you turn off the push setting ?

Interesting - with "standard" it does indeed change to my public IP (NAT outside). So it should work fine with a private SIP server on the same LAN.

Not tried it within the LAN (private IP) for ones own SIP box. I started using Acrobits after I'd given up on my FBX/ Asterisk box et al post pandemic. Hence provider based VoIP service.

Can anyone definitely confirm it will work with private-IP based SIP server only (without push)? Literally like an on premises extension would.

Edited by Pheasant (Tue 11-Feb-25 09:07:41)

Acrobits Softphone is good and worth paying for, tried a few free ones which were not nearly as good.