I’ve been experimenting with SIP (Session Initiation Protocol) for a while. Our primary phone service is through a VOIP (Voice-Over-IP) provider that uses SIP. Recently I took another look at SIP clients for Linux.
While Skype continues to provide the best audio and video quality of all the VOIP solutions I’ve used, using it with the the old public telephone network isn’t free. When a family member was scheduled to be away somewhere that mobile service was almost nonexistent but wifi would be available, I decided to take another look how they could use a smartphone SIP client to ring us up at home using our existing SIP provider.
C-SIP Simple is still the best SIP client for Android, and that’s what I chose to install and configure for the phone client (I downloaded it via the open source F-Droid repository for Android, rather than Google’s Play store since I usually avoid logging into Google). After setting it up on several phones (each with their own extension off our main SIP account), I decided to review Linux desktop clients as well.
Following lots of testing, I settled on SFLphone because it was both simple and reliable. As SFLphone is developed by Savioir-faire Linux, the company maintains a yum repository for Fedora where the necessary sflphone-gnome and sflphone-plugins packages can be retrieved.
The main limitation with SIP is that it can be, and often is, blocked by corporate firewalls. So, for example, when I’m using a wireless connection at any of my employer’s facilities I’m unable to connect to my home SIP provider.