The State of Mobile VoIP, part 3: SIP clients

At this point in time (May 2013) there is an abundance of SIP clients for Android. 'Twas not so a short few years ago.

First, in early 2009 I believe, came sipdroid. I think it was the API additions of the Cupcake release that allowed the software to stream audio to/from the speaker/microphone. sipdroid was a simple client that allowed making basic SIP-to-SIP audio-only calls.

Later, as front-facing cameras became more prevalent, sipdroid added videoconferencing. I think it was the first app with video but I can't say for certain. They were certainly proud of the addition.

Other than this capability, sipdroid is fairly basic. It only allows 2 accounts and it doesn't seem to be possible to dial out of the second account. The second account appears to only be there for receiving calls.

sipdroid has some support for setting up a pbxes.org account, but that's not much of an addition.

The other major SIP client is csipsimple. It is a lot more sophisticated. Its major feature addition is encryption. It can use SRTP, ZRTP or just TLS. Additionally, csipsimple supports multiple accounts. Right from the dialler, you can pick whichever account you wish to use to make the call. Also, it comes with an account set-up wizard for major providers. csipsimple has both STUN and ICE support. Video conferencing is possible on csipsimple but I don't know the details. The maintainer - Regis Montoya - is very responsive and generally cool guy.

It used to be that the version of csipsimple in the Android market was useless. It wouldn't make calls, and you had to download the latest nightly version to get anything that worked. However, the market version has been pretty good for a while now, and I think they even just uploaded the blessed 1.0 version.

There is a separate download for the extra CODECs. I would recommend them if the people you talk to use them also, but I personally think the regular CODECs are fine.

The last client I should mention is of course the built-in SIP stack that originated in Gingerbread. It is quite basic. It does not integrate with the dialler. All it can do is call other SIP targets. In the Contacts application, if you've ever seen "Internet call", this is what they're for. You enter something like sip:someone@someplace.com and then you can call it. It only supports G.711 (ulaw and alaw). It doesn't support STUN or ICE, although occasionally it will work (I assume if your network will "fix up" the packet for you.) Frankly, I place it roughly in the category of "fun toy", like walkie talkies when you were a kid, but I wouldn't rely on it.

The hands down favorite is csipsimple. It just does everything and if it doesn't, you can re-configure it. Since it has matured, I've actually been using it for most of my calling.

Which brings us to the next important topic...

Next: SIP providers