What is sip telephony, technology features

The appearance and abundance of English-language signs and abbreviations on the Internet often scares an unprepared or lacking appropriate education user. Web pages are full of abbreviations IP, VoIP, SIP and so on.

Sip-telephony for calls over the Internet

To understand and understand what sip telephony, technology features, it will take a little time and attention.

Sip telephony - why is it needed and what is it

Most often, computer users encounter this concept when studying the capabilities of virtual telephone exchanges or, if necessary, find a way to make calls over the Internet.

If we consider these concepts in terms of "globality" with ranking in descending order, then:

• IP is the Internet Protocol for data transfer. Thanks to it, a connection is made with other devices in the global Internet information network.
• VoIP is a technology for transmitting audio data over the Internet. It is it that is used for audio and video calls between users, or when participating in online lectures and webinars.

VoIP Telephony Connection Diagram

Telfin is one of the companies that provide services for connecting SIP telephony. Telfin has more than 30 ready-made integrations with CRM in its arsenal, a large pool of numbers from Russia and other countries, high quality connectivity and reliability.

IP-telephony is a technology for transferring audio and video data between users using the Internet. IP-telephony includes many types of protocols that provide compression, encoding, decoding, data exchange order. One of these protocols is Sip.

Thus, Sip is one of the communication protocols for multimedia messaging, which ensures the operation of IP-telephony.

When and by whom was Sip-telephony invented?

The history of the protocol began in 1996. The development was led by the IETF MMUSIC Working Group and the combined efforts of Henning Shulzry and Mark Handley. Khening Shulzry worked at the University of California, and his partner at University College London.

In November 2000, the Sip protocol was officially adopted and approved as protocols for the 3GPP and IMS projects.

Block diagram of Sip-telephony

The key principles of the protocol are:

1. Simplicity. To complete the connection and transfer data, only 2 messages “question” and “answer” and 6 operations are used: invitation, disconnection, options, confirmation, cancellation and registration.

• Stage “invite” - a new connection and invitation to the user's network is performed.
• Stage “bye” - if the user wishes, his connection with other network participants is completed at any time.
• Stage “options” - information about the supported characteristics is transmitted and verified either in the “client-client” or “client-server” pair.
• Stage "ask" - after the invitation command, the user gives or refuses the dialogue.
• Stage "cancel" - stop user search.
• The registration stage is the transfer of information about the user's location to the SIP server.

1. Independence from the transport level.
2. Complete freedom of movement of the user. The SIP phone client receives a kind of unique “mobile” (identifying) number and can move around the world with this number assigned to it. To make a call, access to the Internet at a speed of at least 64 Kbps is sufficient.
3. The possibility of scaling the network, which is implemented quite simply and does not require large investments, as in the case of an analog PBX.
4. Protocol extensibility. With the advent of new services and options, the protocol is flexible enough to expand the functionality with new requirements.
5. Compatibility with other protocols. Sip protocol can work in combination with other protocols and PSTN networks.

What do you need to make or receive a call?

For the average user, there are several use cases:

1. Using a PC or laptop. To do this, just install the software Sip-client ("softphone") and connect or check the operation of the headphones and microphone.
2. Using a tablet or smartphone. The software device for the smartphone is installed, connection / registration is performed. A call can be made both via mobile 3G or 4G networks, and Wi-Fi.
3. Special Sip-phone connected to the router.
4. Using a VoIP Gateway. A regular telephone is connected to the gateway, and the gateway, in turn, to the router.

How does it work "on fingers"

For example, Anna is on vacation in Cyprus and calls a Russian organization to check for plane tickets home to St. Petersburg. Anne’s smartphone has a special program, a Sip client.

The Russian company also switched to a virtual PBX with support for Sip-technology.

Anna dialed a Russian number in the program. The Sip server to which her smartphone is connected is looking in the global network for the server where the “number” of this Russian company is registered. The destination server responds and connects after exchanging IP addresses. In the process of communication, “voice messages” Anne are compressed, encrypted and compressed are transmitted to the server of the interlocutor, which in turn decrypts the message and reproduces it in analog quality.

Sip Call Scheme

If one client uses a Sip application or device, and the other client uses a mobile cell phone number, then the scheme changes slightly. The IP-telephony server is looking for a second server, if it cannot be found, it makes a call directly to the end device using standard technologies, but also with signal compression and encryption.

Where applicable

The scope of Sip-telephony features is huge:

• It is widely used by both commercial and state organizations for “intra-corporate” communication or communication with other persons. Almost all major call centers and federal retail chains or companies operate using IP-telephony.
• Currently, video intercoms with support for communication via Sip-protocol are available.
• Individuals also use equipment and programs that support Internet calls to communicate with friends in other cities or countries, thereby significantly reducing their costs.

What is the advantage of Sip telephony

Using this technology has firmly mastered business areas.

1. The ability to use multi-channel numbers and savings on the deployment of a virtual PBX. This is significantly cheaper than an analog solution. The principle of operation of IP-PBX involves the distribution and forwarding of calls to employees, and, therefore, the common number is always free.
2. Sip installation is carried out in the shortest possible time. Enough PC, laptop and Internet access. In the absence of a dedicated line, you can use 3G or 4G.
3. Payment is made at basic rates regardless of the location of another subscriber.
4. An ideal solution for companies with a large number of branches in other regions.

Virtual PBX structure for working with regions

1. CRM integration and call tracking capabilities. Call tracking will allow you to track the advertising source and use the information received to analyze and improve the marketing strategy. The combination with CRM will help to automatically accumulate customer information and increase the efficiency of the sales department.
2. The software and hardware of the virtual telephone exchange provides the option of recording calls, which can be used to analyze the work of an advertising campaign or employees in general.
3. Encryption technology increases the security of the data transmission channel and, therefore, the safety of commercial information.
4. You can configure different forwarding rules: to mobile and landline phones, tablets, PCs, etc.

What "Softphones" exist for laptop and Android devices

Many companies are developing the IP-telephony market, providing Sip-clients for both desktop computers or PCs, as well as smartphones and tablets.

The most popular for PC users are the following.

Softphone Telfin

Softphone for iOS, Android and Windows

Advantages of using

• There is no need to buy additional equipment, you can install the application and make calls from a mobile device (the “Per Minute” tariff is used).
• Significantly reduced communication costs: based on softphones, you can create a full-fledged corporate telephone network and make calls within the company absolutely free.
• Employees become more mobile and have the opportunity to communicate with colleagues and clients, being anywhere in the world: softphone allows you to make calls from any mobile device.
• By default, it works through its own PUSH server, which allows significantly less influence (when working in the background) on the battery drain of the smartphone. Plus, when a number of programs that do not work through PUSH fall asleep in the background and do not always ring when an incoming call, Softphone Telfin wakes up and rings stably.
• Very easy to set up. Just scan the qr code.

How much is?

To use the Telfin.Softphone softphone, there are no mandatory monthly fees or minimum fees.

You can put as much money into your subscriber account as you need and pay only for calls made.

Communication within the corporate network is free. All outgoing calls are made according to the “Per Minute” tariff.

On the website of the company Telfin you can install this mobile application and connect SIP telephony.

3CXPhone VoIP Softphone

The program was created by 3CX, which develops and integrates IP-PBXs. Using the program is absolutely free. Just download and register. Payment is made for the fact of the connection, taking into account the time of the call.

Windows application 3CXPHONE

Solution Advantages:

• Easy to install, configure and use.
• Accessible and intuitive interface.
• Work with the most popular Sip-servers.
• Support for 5 active lines with the ability to switch.

The application has 3 working screens: current call, notebook and video call.

On the main screen of the current call is a convenient classic keyboard for dialing. It is possible to record a conversation or put on hold.

Notebook will allow you to make a fairly large amount with the most important contacts.

Sip client Zoiper

Using the program is also free. Built-in Russian interface simplifies the development process.

Solution Advantages:

• A large number of settings.
• Convenient call management.
• Automatically configure the application after registering account information.

Windows application Zoiper

The application has one main window, where contacts are placed on the left side of the screen, and a call is managed on the right side. The buttons on the control panel allow you to record a conversation, enable or disable the microphone, put the call on hold. Unfortunately, the possibility of a video call in the free version is blocked. To use the function and gain access to even more client settings, you need to purchase a PRO version.

Sippoint

The program was developed by Sipnet, which provides virtual telephone exchange services.

Solution Advantages:

• Fully Russified application.
• Good sound quality when making calls.
• Intuitive interface.
• Video Call Support.

Windows Sippoint Application

The application’s working screen has one window, a notebook is located on the left side, the right side of the workspace is reserved for chatting with SIPNET users, making and managing calls, and video calls.The program keeps a history of calls, offers the ability to record a conversation, put on hold, control the speaker and microphone. To use the Sip client, you need a SIPNET account.

Owners of portable devices are not deprived of offers either. For smartphones and tablets, there are thousands of applications on the Google Play and iTunes Store.

Zoiper IAX SIP VOIP Softphone

Lite version is absolutely free. Pro version costs 550 rubles. The advantages include low battery consumption, user-friendly interface, good sound quality through the use of a large number of kodaks, tuning tunes. Russian language is not supported.

Zoiper for smartphones

Mizudroid SIP VOIP Softpone

The application is absolutely free. Among the advantages were noted such characteristics as: a small application volume, minimal load on the processor and battery of the device, support for several Sip accounts, good noise reduction and smooth sound, lack of advertising. Unfortunately, the client does not support video calls, the possibility of settings is minimal, a simple ascetic interface, without support for the Russian language.

Muzidroid for phones

SIPNET NetCall

The advantages of the application include the presence of a Russian-language interface, in addition, the application is famous for its good smooth sound quality, high noise immunity.

There is also a notebook, call history, the ability to manage settings. Sorry, video call is not supported.

NetCall Android Application

Given the development trend of software and hardware from leading manufacturers with support for Sip-technology, you can be sure of the trend of reducing the cost of both equipment and calls to long-distance and international destinations.