SIP number: what it is, its features and advantages of use

When and how SIP numbers appeared

SIP numbers emerged in the context of the development of Voice over Internet Protocol (VoIP) technology, which allows voice and other multimedia data to be transmitted over the Internet. The term SIP (Session Initiation Protocol) itself stands for Session Initiation Protocol and is used to establish, manage and terminate multimedia sessions such as telephone calls over an IP network.

The history of the emergence of SIP numbers is linked to the development of digital telephone systems and the transformation of traditional telephone networks towards IP technologies. Here are the key stages of their development:

1. The birth of VoIP. With the advent of the Internet and the growth of data transmission speeds at the end of the twentieth century, VoIP technology became possible. The first systems of voice transmission via IP-network appeared in the mid-90s.
2. SIP standardisation. In 1996, the IETF (Internet Engineering Task Force) officially standardised SIP as a protocol for managing multimedia sessions in IP networks. This was a key step for the development of VoIP technologies.
3. Introduction of SIP numbers. With the introduction of the SIP standard, SIP numbers began to appear. These can be displayed in different formats, but in general allow voice calls to be made using an IP address or other identifier tied to the user.
4. Popularity and Expansion. Over time, SIP numbers have become widely used in business and the private sector in place of traditional phone numbers. They offer greater flexibility and accessibility as they can be easily configured for forwarding and integration with different VoIP services.

What SIP numbers are and what role they play in the SIP protocol

A SIP number is an identifier that is used to make and receive audio and video calls over the Internet using the reliable Session Initiation Protocol (SIP). Unlike a regular phone number, this one is created in a virtual format and is not tied to a specific location or physical device.

To use a SIP number, you need a device with an Internet connection — IP phone, analogue phone with VoIP gateway or any other device that can download the appropriate softphone software (Zoiper, PortSIP, etc.).

Virtual numbers perform several key functions in the SIP protocol:

• User identification. Each SIP number uniquely identifies a user or device on an IP network, allowing other participants to find it to initiate phone calls or other communication sessions.
• Communication routing. SIP numbers are used to route communication through the IP telephony operator to the final destination. They determine where a SIP request should be routed to in order to establish communication.
• Format of requests. There are several types of SIP numbers, such as individual SIP addresses for users and domain SIP addresses for services or group communications (e.g. online conferencing), which determine who to reach and what type of connection should be established.

Basic principles of SIP-numbers operation

The process of making calls to landline numbers, mobile numbers or other SIP numbers using SIP technology is generally as follows:

Step 1: Registration on the SIP server

A SIP client is configured on the user's device and a connection is established between the client and the SIP server using identification data (SIP address, SIP login and SIP password). The client sends a registration request and if all the details are correct, the connection is established.

Step 2: Initiating a call

The user selects the number he wants to call (landline, mobile or SIP number). After that, the SIP client forms a SIP request to initiate the call, which is sent to the SIP-server.

Step 3: Establishing a connection

The SIP server processing the request checks the correctness of addressing and searches for the subscriber in the network. If the subscriber is found and available for communication, an audio session is established between both clients.

Step 4: Ending the call

After the call is completed, the user closes the connection. And the SIP server releases the resources intended for the session and prepares for the next request.

How a SIP number differs from a mobile and landline number

SIP numbers, mobile and landline are widely used for communication in the modern world. To understand which one is better to choose, you need to understand the differences between these types of numbers:

1. Technology.
   

   VoIP (Voice over Internet Protocol) technology is used to make calls from SIP numbers. Fixed numbers are based on PSTN technology (Public Switched Telephone Network), while mobile numbers use GSM technology (Global System for Mobile Communications).

2. Location.
   

   SIP-number is not tied to geographical location, which is very convenient. Whereas the use of a landline number is geographically limited, and the condition for using a mobile number is the availability of GSM connection.

3. Equipment requirements.
   

   Devices for making calls from SIP numbers don’t require laying a telephone line: an Internet connection and a VoIP device are sufficient. To use landline numbers, you need a phone line and a landline. And to use a mobile number you need a mobile device and a sim-card.

4. Scalability.
   

   Connection of a SIP number doesn’t require laying additional communication lines, and the number itself is easily scalable depending on user needs. Fixed-line communication is characterised by limited scalability and requires additional communication lines in order to increase the number of numbers. Mobile communication can be scaled up only by adding new mobile numbers (by purchasing sim-cards).

5. Choice of features.
   

   A SIP number offers a wide choice of additional functions (call forwarding, voicemail, IVR-menu, etc.). Whereas the choice of functions of a landline number is limited to the basic ones, and a mobile number — only a few additional ones (call forwarding and voicemail).

6. Cost of calls.
   

   Different operators offer packages of services with different content. The choice should be made based on the tasks that the number should fulfil. Fixed-line calls are the most expensive. And the cost of mobile and SIP-telephony depends on such factors as the direction of calls, functionality, etc.

7. Flexibility of settings.
   

   SIP numbers with their high level of customisation flexibility win out over both fixed line numbers with their limited customisation functionality and mobile numbers, whose level of flexibility is characterised as medium.

8. Support for video calls.
   

   Unlike a landline number, which supports only voice calls, SIP and mobile numbers support both voice and video calls.

When choosing between a SIP, mobile and landline number, consider your own needs. But if mobility and affordability are important to you, SIP number is the best option among them.

Applications of SIP numbers

SIP numbers can be conveniently used in business to organise workflow in various formats:

• Office telephony. The number tied to your SIP telephony is suitable for receiving and making calls at workplaces, as well as setting up voice menus and forwarding calls to the right employees without installing traditional phone lines.
• Call centre. SIP numbers connected in call centres can be used for routing calls to specialists, setting up waiting queues and recording conversations in order to increase the efficiency of their work.
• Remote working. Employees who work remotely just need to set up a SIP number on their computer or mobile device — and that's it: you can receive and make calls anywhere you have access to the Internet.
• International calls. The use of SIP numbers due to sending voice calls via the Internet allows you to significantly reduce the cost of international communication compared to the use of traditional telephone operator numbers.

SIP numbers can also be used for personal purposes to securely communicate with your family or friends using an Internet connection. After all, it is essentially an ordinary landline number, which can be easily connected to the Internet and thanks to this expands the possibilities of users.

What are the advantages of using SIP numbers

Compared to using conventional numbers, SIP telephony provides users with a number of advantages:

1. Geographic flexibility. SIP numbers don’t require physical attachment to a specific location, so it is convenient to use them for companies with branches or online employees.
2. Cost savings. Since SIP telephony works via the Internet, it allows you to reduce the cost of calls from mobile to landline, international calls and thus save your expenses on telephone communication.
3. Flexibility and scalability. SIP numbers allow you to add or delete numbers, set up additional features and call forwarding according to your business needs without additional equipment.
4. Advanced functionality. SIP telephony offers a wide range of additional features to improve the efficiency of communication within the company (voicemail, automatic call forwarding, conference calls, etc.).
5. Integration with other systems. SIP numbers can be integrated with CRM systems and messengers in order to automate processes and simplify interaction with clients.
6. Increasing the recognisability of the company. Using beautiful SIP numbers helps to grab the attention of potential customers by making your contact easier to remember, and you get new customers.

To order a SIP number from Maxnet, just choose a tariff and leave an application on our website. After that, our manager will contact you to finalise the contract.