SIP-addressing is logical, of the same type as URL in HTTP. And the most natural – to use the electronic mail as the SIP address. There are permissible varied parameters by the address: for example, it is possible to indicate the regular city telephone number, additional telephone, and the parameters of modem connection etc.
VoIPCall is a Minneapolis based Internet Telephony Service Provider [ITSP] that provides a first class Voice Over IP calling service designed for business customers, Telcos, ISPs and government entities around the world.