How does a virtual phone number work

From Virtual-Phone-Number

From the point of view of the user, the virtual phone number works just like a regular phone number. The only differences may be a slightly higher time in connecting the call, and the loss of the callerid.

If we look at the underlying technology, the virtual number starts in the PSTN (Public Switched Telephone Network). From there, the call is routed, frequently via IP, to a softswitch. Many people associate voice over IP with bad quality. In fact, it does not need to be the case. As long as the IP links are properly managed, the quality of the calls will be indistinguishable froma regular call. In fact, most phone companies route most of their calls through VOIP -- without telling anyone.

Once the call gets to the softswitch, the real work starts. The softswitch is the one that needs to coordinate which call goes where, and how to charge for it. Large virtual number suppliers will have more than one route to each destination, and will route according to quality.