VoIP on an iPhone

I recently decided to move to naked adsl2+ from a normal adsl2+ with iiNet. I didn’t want to pay line rental anymore. Anyway, as part of the package, I get VoIP for free which includes free local and STD calls.

So I dug up my old ATA box from Linksys, PAP2-NA, basically what the unit does is enable you to use your existing analogue phones as VoIP handsets. It was rather straightforward configuring the PAP2 to work on iiNet’s  VoIP network.

I then wondered if there was a SIP client available for the iPhone so I could use it for VoIP calls as well. A quick browse of the Apps store found a couple of promising SIP apps, iSipSimple and Acrobits softphone. I decided to try iSipSimple first after reading some positive reviews. I was able to get it up and running after a bit of fiddling with the setup. I was able to make and receive calls using both Wi-Fi and Telstra’s 3G network.


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However, after a few days of usage I found two issues:

It doesn’t automatically reregister itself when going between 3G/Wi-Fi networks and vice versa, I have to manually reregister the app.

The other issue is that it would not receive any incoming calls if it was in the background.

Apparently, IOS4 does not support UDP running in the background mode rather they suggest using Apple’s push notification. I couldn’t get it to work for me so if it was in the background I don’t get the call.

These two issues are a deal breaker for me so I decided to purchase and Acrobits and give that a go and see if it would be the SIP app for me. After punching in the necessary details, it worked first go! The setup was way too easy.



Everything was much simpler and intuitive with the Acrobits app, I just bring it to the foreground and it automatically reregisters itself with iiNet. I was also able to get it working in background mode. Apparently if your VoIP provider’s SIP server supports TCP instead of just UDP (port 5060) it will work in background mode and alert you if when there is an incoming call.


Issue when moving between 3G and Wi-Fi

One small issue is that if the app is in the background and you go between 3G and Wi-Fi or vice versa it loses connectivity, you need to quickly bring the app to the foreground, it then quickly reregisters itself with iiNet/Telstra and you are back in business. You can switch it back into the background. This would be the perfect SIP app if it could reregister itself whilst in the background when going between 3G and Wi-Fi.

The voice quality is pretty good with both G.711 and G.729a codecs. I limited uplink to a maximum of 20kbps (bittorents) and moved all the VoIP related rules to the top on my firewall to give it priority. I have not had to resort to any traffic shaping yet.

I also purchase the G.729a codec as it uses less bandwidth than G.711 codec, especially when using it on 3G to minimise cost.

Configure Acrobits for iiNet

Select Settings

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Select SIP Accounts Select “+” symbol

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Select Generic Account

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Settings for iiNet:

Username: Your_ID (iinet provided phone number)

Password: iinet provided password
Domain: iinetphone.iinet.net.au
Display Name: Your_Name
Incoming Calls: In Background (Default: On)

Incoming Calls, Background Options

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Select Background Options

Transport Protocol: tcp (required to receive calls whilst in the background)

Expires: 1700


Advanced Settings

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Transport Protocol: tcp

Proxy: sip.nsw.iinet.net.au

Proxy Port: 5061

RTP Port Start: 16384

RTP Port End: 16482



Quickdial allows to you to contact people that you call on a regular basis. You can add you contact’s photo which is a cool feature, especially whilst driving, it is easier to spot their faces instead of trying to look for their names in the tiny fonts.




It also has a log of all your recent calls, both incoming and outgoing including missed calls too.



Acrobits uses your existing  iPhone


contact list, which is pretty cool. So you don’t need to keep

a separate list of contacts



It is also possible to record your phone calls but it emits a beep every few seconds to let the other party know that the conversation is being recorded. 


Just tap the red record button if you wish to record the call. I have tested it a couple of times and it worked really well. The recording is on by default but I turned it off as I found the constant beeping annoying. You can change it in Settings>Preferences>Call Recording.


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A little tape symbol under the caller’s name denotes that the conversation or call has been recorded. If you wish to listen to it, tap on the little blue arrow. Tap on the blue arrow, again, on the second screen.


Tap on the “Play” button and listen to the recording of the conversation. You can either email to the other party or delete it if you no longer need it.


I love this app, I have had it for a few weeks now and it has perform flawlessly. I highly recommend this app to anyone looking for a SIP client for their iPhone. It will also supports Google Voice when it becomes available in Australia.

Now anyone can call my home number and I am able to answer it on my iPhone anywhere in Australia and they are none the wiser.

All my testing was done on iiNet’s VoIP and Telstra’s 3G network. My assumption is that all other ISPs/Telco in Australia will have the same QoS and therefore should have no issues but I cannot guarantee that this will be the case.



Internet Phone said...

Fortunately or unfortunately, there have been lots of applications voip service on iphone in the last few years. Every third software how is working on an application for iphone. I think now software engineers should pay attention to other mobiles also and try to make them more voip compatible.

Ayrton Sue said...

Fantastic Blog and very helpful in setting up the Acrobits Softphone App. Thanks very much

lozzmann said...

Hi Ayrton,
Thanks for visiting and you are welcome.