Why incompatible codecs calling with Sipdroid under Android?

[androiduser]

Hello,
I have got VOIP unlock key with FreePhoneLine, so I have a free phone number with VOIP access.

Problem:
I cannot call any number with FPL as if there is a problem with incompatible codecs, but is it really so?

All right, here are all the details:

I use Sipdroid 3.9 app under Android 6.0.1 on my Motorola Moto G XT1032 (1st generation).
I can use other VOIP provider (Zadarma.com) and make/receive calls through it.
I use my home wifi, its signal is excellent.
Sipdroid gets registered with FPL just fine.

When i try to place a call with FPL, sipdroid says "incompatible codecs".
If I recieve a call on FPL, I hear nothing and other side hears nothing.

So I went into Sipdroid settings and checked the available audio codecs. All of them were enabled to use with wifi.
Among them there is PCMU codec, also called g711-u (uLAW) - which is supported by FPL, according to the official info published at
http://support.freephoneline.ca/hc/en-u ... /212430746

Now, to make things clear, I disabled all codecs with exception of PCMU/g711-u and tried to make/recieve calls.
The same problem appeared: "incompatible codecs".

Why? What is wrong here?
Maybe Sipdroid and FPL just name the same codec differently (PCMU vs G711U)??

Please help, if you can.

P.S. Unfortunately Sipdroid does not support G729 codec (accepted by FPL) because of its licensing restrictions.
So, I could not use it.

[bridonca]

SIPdroid should be able to support G.711, of which freephoneline uses.

[androiduser]

SIPdroid should be able to support G.711, of which freephoneline uses.

Yes, it should, but it somehow doesn't, at least in my case
You can give it a try if you wish.

Today I checked also a couple of other open-source Android voip apps with FPL.
Results:

1. Linphone does work. It supports G.711 (µ-law, A-law) codec, see here: https://en.wikipedia.org/wiki/Linphone

2. CSipSimple also works. It also supports G.711 (µ-law, A-law) codec, see here: https://en.wikipedia.org/wiki/CSipSimple
During call, I can see it uses either G711A or G711U (depending on their priority in the list)

So, it is really strange why Sipdroid says "incompatible codecs."

When I have some time, I am going to try Lumicall, which is a fork of Sipdroid.
This article
http://www.voip-info.org/wiki/view/Lumicall
says it supports G729 codec.

[androiduser]

Here is an update from me
I will share some final results and thoughts.

1. Lumicall was a too complicated app for me. I could not figure out what is what there. Not recommended.

2. Sipdroid did not work with FPL even after full reinstall of Android OS on my smartphone.
I don't know why.
Also, I noticed that it often gets disconnected from FPL with a message, something like "too many attempts to connect".
So, I left Sipdroid at that.

3. Among other SIP apps I liked MizuDroid (small size, but closed source; supports G729 codec) and the best of all, CSipSimple (open source, frequent updates, published at https://nightlies.csipsimple.com/ ).

So, my recommendation of Android SIP app for FPL would be:
- first, Sipdroid, if it works.
- second place: CSipSimple
- third place MizuDroid

[Liptonbrisk]

More than 5 registration attempts within a 5 minute period using any FPL SIP server will result in a temporary IP ban with the specific FPL SIP server being used.

Consequently, these registration timer intervals are very important:

a) Registration Interval: 3600 seconds (1 hour)
b) Registration Expiry: 3600 seconds (1 hour)
c) Failed Registration Re-Try Interval: 120 seconds
http://support.freephoneline.ca/hc/en-u ... redentials

Note that that only one device or softphone can be properly registered with an FPL account at any time.
The most recently registered device or softphone will ring for incoming calls. Others will not.

[androiduser]

Thank you for the useful info.

However, I could not find how to see or change these settings in Sipdroid app.
I can see and change the settings in CSipSimple though.

[androiduser]

I think I finally understood why Sipdroid does not work properly on my smartphone.
And other SIP apps do, for example, CSipSimple.

I wrote that I use Android OS v. 6.0.1 on my smartphone. It is not true altogether.
In fact, I use stable version of CyanogenoMod v. 13.0, based on Android v. 6.0.1.

I can install Anroid .apk files on my device, but I guess the two systems are not 100% compatible.
Sipdroid .apk package is only 852 Kb in size (in comparison, CSipSimple is 9.5 Mb), so it is evident that Sipdroid uses some components from Android system itself.
So, I guess, when one has CyanogenMod installed, Sipdroid cannot find proper components - codecs in my case.
- Because they might have other names, or just are absent in the system.

All right. I hope my experience will be helpful for those people using Cyanogenmod.