What is a Virtual phone number?

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A virtual phone number is a VoIP number or gsm subscriber phone number.  It is similar to any other phone number, mobile or fixed-line subscribers have. But the main difference is that this number does not belong to any sim card or to any fixed line device.

VOIP providers allocate the number along with the VOIP account.  A virtual phone number has many advantages.  The main advantages are for business.  For e.g, if a company has set up a customer care office in India, but the service is launched in many other countries.  They have a local number for each country. It is a very difficult task to set up customer care offices in each country. Here comes the main role of the virtual number.

A service provider buys virtual numbers for each country, and the callers feel that they are talking to local guys.  The virtual number provider routes all calls to the India call center.

VoIP and Virtual Number:

VoIP enables the virtual number concept. A no VOIP number has either the sim card or a fixed-line.  The VOIP gateway provider terminates the request for the virtual number and connects to the actual subscriber for voice and data.  So it’s like a getaway between IP and PSTN network. As all is on the IP network this enables a cost-effective service to the service user.

The voice Call flow for Virtual Number :

Voice is the primary service that a telecom network provides. When a user dials the virtual number. The call reaches the service provider. Provider Knows that this is called for the virtual phone number by looking at its database. If the phone number is not provisioned then the call is dropped, else the actual number is found and the provider initiates a new call towards the actual number and connects both the calls.  On the VoIP side, the signalling protocol is SIP, and on the PSTN side, the signalling protocol is ISUP. Sip if for setting a voice session over IP network and ISUP is the protocol for establishing a Voice Channel over the PSTN network or SS7 network. The called actual number can be a mobile number, a fixed-line number, or a call center number via SIP trunking.

SMS Flow for virtual number:

SMS or text is another essential service for any subscriber. Similar to voice, the VOIP provider for the virtual number forwards the SMS to the actual number and the sender gets the delivery report for the successful submission to the number.