SIP Softphone on Smart Phone

SIP softphone on smart phone can be used as PBX’s extension in either WIFI or cellular network. Moreover, you can add a DID number to your SIP account. If so, SIP softphone could be the alternative of cellphone.


Free SIP Softphones on smart phone:

You may use free SIP softphone as PBX’s extension instead of IP phone or VOIP gateway for Analog phones. This might be important to get a Free PBX

Grandstream wave lite

  • Free
  • Free G729, G722 and Opus codec
  • Multi-account
  • Support SIP message
  • Support both Android or iPhone
  • No Push Nortification

Zoiper:

  • Free version with only one SIP account
  • Paid G729, G722 and Opus codec
  • Support SIP message
  • Paid Push Noritication
  • Suport both Android and iPhone

Linphone:

  • Free
  • Multi-acccount
  • Free G729, G722 and Opus codec
  • Support SIP message
  • Support Android only
  • Push Notification not working

Paid SIP Softphone on Smart phone

Groundwire

  • One-time pay
  • Multi-acccount
  • G729, G722, Opus codec included
  • Support SIP message
  • Support both Android and iPhone 
  • Push Notification included

Groundwire for SIP Softphone on Smart Phone

Acrobits

  • One-time pay
  • Multi-acccount
  • G729, G722, Opuscodec included
  • Support both Android and iPhone 
  • Push Notification included

Zoiper Pro

  • One-time pay
  • Multi-acccount
  • Paid G729, G722 and Opus codec 
  • Support SIP message
  • Support both Android and iPhone 
  • Push Notification included

Bria

  • Monthly pay
  • Multi-acccount
  • G729 codec included
  • Support SIP message
  • Support both Android and iPhone 
  • Push Notification included

Tips about SIP Softphone on Smart Phone:

Low bandwidth codec:

As Smart phone use Wireless network connection either WiFi or 4G/5G, but might not be stable enough in places with poor sighnal. G729, G722 or Opus codec is recommended! 

However, G729 is old technology, which may increase CPU’s payload. The voice is actually lossy due to compressed too much. Opus becomes popluar recently years because it’s with ultra-low bandwidth, low CPU payload and high-quality voice, so set Opus as the 1st priority if possible.

Text message

Many softphones support SIP message, which could be as alternative of  cellphone’s text messge, but some institutions like banks don’t send a vertification text message to a VoIP phone number.

Push Notification

Either iPhone or Android will kill the app in the background  to reduce energy consumption.  If the softphone was killed after display turned off some time, you could’t receive an incoming call. Fortunately, software could be woken up via push notification, which replays on Apple or Google notification server and will increase developper’s costs. This is why free softphone usually doesn’t come with push notification. 

Moreover,  phone consumes less power if using push notification.

Energy Consumption

UDP or TCP

SIP softphone usually uses either UDP or TCP protocol to connect PBX server. TCP consumes less energy. UDP is default in most softphones, so you need to change UDP to TCP in settting if your PBX server supports TCP protocol.

Keep softphone runing in backgound?

At present, only Android phone allows software or other apps working in backgound. iPhone seems to allow it in a little more time, but still kill softphone in background after display is turn off  long time


Conclusion on SIP Softphone on Smart Phone

You can use free SIP softphone for personal or hobby use.

However you should buy a paid softphone with G729 and Push Nortification for business use.