Try one, or try them all, they're free!
We frequently are asked by our customers who are in the process of installing or configuring a new PBX system, "which softphones do you recommend?." While we support most SIP-based softphones available on the market, we do tend to work with some vendors more than others.
Below is a list of the more popular SIP softphones, all of which are completely free download and use. Choosing the right softphone for your particular needs will depend on many factors, like which operating system you plan to use, what phone features you require, and what PBX system it will be connected to.
Have a look, download and play around with one or all of them to find the right softphone for your requirements.