Express Talk SIP Service Providers PC-to-PC and PC-to-Phone SIP Providers SIP (Session Initiation Protocol) is a widely used communication signalling protocol used for real time voice and video communication over the internet. SIP Service Providers SIP service providers allow you to make worldwide calls using Express Talk. Most companies offer free PC-to-PC calls because they make their money from providing PC-to-Phone connection services. That type of gateway service allows calls to and from traditional telephone line will come at a fee, but will tend to be cheaper than the rates from the phone company. |  Download Express Talk Purchase Online |
