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.
NumberGroup provides business quality VoIP services to wholesale operators and SIP Trunk customers worldwide. We have over 1,000,000 UK and Internaiton telephone numbers are are a license UK operator with direct PSTN connectivity.