Provides IP telephony. Organization of audio and video communications in computer networks

Recently, more and more technical innovations have appeared, and people do not have time to keep up with the constant changes in technology. Because of this, the communications market simultaneously offers both outdated and technically more advanced telephony technologies, the difference between which is vaguely understood by users. Let's look at what the characteristics are, what are the advantages of IP telephony, and what opportunities this system provides to the user.

This is what IP telephony provides in the office, its benefits and advantages over analog communication systems:

• reducing the cost of any kind of incoming or outgoing calls, especially for international and long-distance calls;
• high signal quality: clear sound, complete absence of voice delay, no echo;
• lack of the concept of “busy”. The great advantage of IP telephony is the almost unlimited quantity lines used under the same number. This quality has been enthusiastically embraced and is widely used in call centers and website support;
• integration abilities. You can easily add new devices to your working IP network, Cell phones, ordinary analog phones, etc., but networks of earlier generations are incapable of this. In addition, networks of different enterprises mounted on different equipment and using different software products can easily be combined into one network;
• and, probably, the most important advantage: an IP telephony network can do everything that the Internet can. For communication systems, this means linking a number to a website, a customizable answering machine, intelligent forwarding, video conferencing, free unlimited calls within an organization, free choice of number and other delights of the information age.

To take a closer look at all the features and benefits of IP telephony digital communications, you need to understand the basis of its work. If telephone communication of the previous generation used an analog data transmission system (with the help of amplifying devices, vibrations from one subscriber reached another), then IP communication was digital. This means that the sound vibrations of the speaker's voice are converted into computer language, and then, at the recipient, back into sound.

Analogue communications can only be made more powerful, but with digital data a computer can do anything it wants, and what it does with it depends on the software and the programmer’s imagination.

You can always consult with us about Internet communication functions, and we will be happy to help you create, install and configure IP telephony and take your company to a new level of working with clients and staff!

What is IP telephony?

The Internet fundamentally changes our understanding of both telephony and methods of communication. IP telephony is a technology that brings together the advantages of telephony and the Internet. Until recently, circuit-switched networks (phone networks) and packet-switched networks (IP networks) existed almost independently of each other and were used for different purposes. Telephone networks were used only for voice transmission, and IP networks were used for data transmission. IP telephony technology connects these networks through a device called a gateway.

Gateway is a device that includes telephone lines on one side and an IP network (for example, the Internet) on the other side. The gateway serves as an interface between the user's device transmitting sound (phone, computer, etc.) and the Internet; it ensures the reception and conversion of data into a form convenient for sending over the Network (and reverse conversion).

During a conversation, voice signals are converted into compressed data packets. These data packets are then sent over the Internet to the other party. When the data packets reach the destination, they are decoded into the original voice signals.

How it all began?

Internet telephony uses the Internet to send an audio message between two or more computer users in real time. The very first Internet telephony software product that allows you to send voice messages over the network, VocalTec Internet Phone, was introduced by the Israeli company VocalTec in early 1995. For the first time, a user of a personal computer equipped with a sound card, a microphone and an Internet connection was able to conduct voice conversations with another similar user, no matter how far they were from each other. Majority software products from the same series, which appeared later, allow users to speak into a microphone and hear the interlocutor’s response through the speakers.

Even before it was born, the new opportunity attracted worldwide attention. The technology has steadily improved and has very quickly reached the point where voice communication is easily possible, and continues to evolve further. Many companies have introduced similar programs. Moreover, in many systems, along with the ability to exchange voice messages added the ability to correspond, send files during a conversation, exchange graphic images and videos.

Types of communication via IP network

Computer - computer . This is the earliest and simplest method of IP telephony. To organize traffic transmission, the user purchases the necessary equipment and software, and also pays the provider for operating the communication channel. The advantage of this option is maximum cost savings. Disadvantage: minimal connection quality.
Telephone - telephone . The subscriber does not need any special equipment, just a regular telephone. Voice traffic is transmitted over an IP network, usually in a separate, expensive section. The devices that organize interaction are gateways, connected, on the one hand, to the public telephone network, and on the other, to the IP network. Voice communication in this mode, compared to the computer-to-computer option, is more expensive, but its quality is much higher and it is more convenient to use. The quality of communication is comparable to that of normal telephone conversation, because The company uses dedicated communication channels. In order to use this service, you need to call the provider servicing the gateway, enter the code and number of the called subscriber from the telephone set and talk in the same way as with a regular telephone communication. All necessary call routing operations will be performed by the gateway.

Computer - phone . The end user does not require any additional equipment. It is enough to have a telephone with touch-tone dialing capabilities on hand. This is necessary so that, having reached the operator, you can enter your code in tone mode, and then the subscriber’s actions are no different from the usual. Most modern telephones, including payphones and mobile phones, provide this feature. If for some reason there is no such telephone, then a beeper can handle the dialing function or, in extreme cases, special program, which can be downloaded from the Internet.

Web phone . Another one new service- this is a call from a Web site that allows you to make a call by selecting a link to the name of the called subscriber from the Internet page or simply dialing the subscriber's telephone number. This decision is aimed primarily at expanding e-commerce capabilities. WEB-phone allows Internet users to talk directly, for example, with a sales representative or a specialist technical support the company he is interested in. Establishing a telephone connection occurs in the usual, familiar way of dialing a number or by simply clicking on a link, which is, for example, the name of a company, the name of the called subscriber, etc. on the Internet page. In this case, the user does not need a second telephone line or interruption of the Internet; he only needs to download a small client software, which can usually be found on the same Web page, and which is installed automatically. On the other hand, a Web phone allows company representatives to answer questions, demonstrate Web pages, and transmit necessary information, thereby improving the quality of services provided.

Advantages and disadvantages of IP telephony

The main advantage of IP Telephony is the lower cost of long-distance and international calls compared to traditional telephony.
Another advantage is convenience. Some people, the number of which is constantly growing, simply find it more convenient to make calls from a computer than to use landline phone. It is possible that in the future, IP telephony will completely replace wired telephony, just as CDs replaced magnetic cassettes, and were subsequently replaced by MP3 players.

The main limiting factor to the large-scale implementation of IP telephony is the lack of mechanisms in the IP protocol to ensure guaranteed quality of services, which makes it not yet the most reliable transport for transmitting voice traffic. The IP protocol itself does not guarantee the delivery of packets, nor the time of their delivery, which causes problems such as “ragged voice” and simply failures in conversation. Today, these problems are being solved: standardization organizations are developing new protocols, manufacturers are releasing new equipment.
Another problem that manufacturers of Internet telephony systems have to solve is the lack of a unified standard for programs that provide communication. Currently, communication over an IP network is only possible if the same systems are used on both sides of the connection being established. For example, a VocalTec Internet Phone user cannot call a FreeTel user and vice versa. This problem arose because the very first Internet telephony programs used proprietary protocols to communicate with each other.

Video communication in computer networks

Until recently, video communication was the province of large corporations and science fiction films. Digital video cameras were too expensive, and communication speeds left much to be desired. Now the situation has changed, but even today video communication is a kind of luxury item, which does not detract from the convenience of this progressive type of interactive communication.
There are many programs for organizing video communication or video chat on the Internet, the most popular include the following:
*Skype
*ooVoo
* ICQ
* Mail.ru Agent
* Trillian
* Windows Live Messenger
*Yahoo! Messenger and others.

How to establish a video call?

The most important condition necessary for the implementation of video communication is the availability of an Internet access channel with sufficient bandwidth. The fact is that during a video communication session, not only voice data is transmitted, but also a video stream. Of course, before being sent to the Network, the transmitted information is compressed using special algorithms that provide multiple compression, however, despite this, the bandwidth requirements still remain quite high. It is usually believed that to ensure high-quality voice communication via the Internet, the “width” of the Internet access channel must be at least 64 Kbit/s; to ensure high-quality video communication, this figure will be at least twice as large.

Software issues
In addition to broadband Internet access, special software will be required to organize video communication. Such software can be an IM messenger like ICQ, Google Talk or any other aforementioned program that has a built-in video chat function. Unfortunately, the listed tools are incompatible with each other - an ICQ user will not be able to communicate with a Skype user. In principle, the average Windows XP user can use the NetMeeting program included with this operating system.
It should also be noted that despite the large selection of programs for organizing video communication or video chat, not all of them are suitable for working in local network, since in order to work they need a server and an Internet access channel. They were developed to organize communication with remote points, and not to work in a local computer network. Firstly, not all networks have access to the Internet, and secondly, video communication via remote server will create a fairly large flow of Internet traffic, and it is usually paid. In general, it is strange to contact a server located thousands of kilometers away in order to contact a neighbor behind the wall.
Of course, there are specialized packages and even hardware solutions for organizing video conferencing on a LAN, but their cost is too high for the average user and they are aimed primarily at companies.

Hardware

To organize a video call you need:
*
* Sound card
* Microphone

The most popular means of “capturing” images transmitted over the Internet is a web camera. In addition to webcams, there are other tools for organizing video communication - videophones. The videophone is a completely independent device that does not require connection to a computer. Such a gadget is connected to the TV using composite connectors; connection to the Internet is usually carried out using an Ethernet interface. You can “call” from a videophone either to the owner of a compatible videophone or to a computer with a webcam and installed Windows program NetMeeting.
However, videophones are quite exotic devices, aimed mainly at the corporate sector (this fact is reflected primarily in their price); Therefore, traditional webcams are of greatest interest to us.

When purchasing a webcam, you should pay attention to the version of the USB interface used. USB interface 1.1 will provide video capture with parameters of 640 x 480 pixels at 15 frames per second. USB 2.0, which has greater bandwidth, will allow you to get 30 or more frames per second.
There is no point in focusing on the quantitative parameters of web cameras - almost all of them have a resolution of 640 x 480 (remember that a resolution of 320 x 240 is sufficient for video conferencing), as well as a built-in microphone.

It is not expensive
Using video communication is completely free, so those who want to use video communication will not have to spend money on purchasing this service; Only broadband Internet access will be subject to payment.
One-time costs will consist of the purchase of a webcam or videophone.
Owners of some laptop models will not have to spend any money at all - many of them are equipped with built-in web cameras.

Advantages and disadvantages of video communication

Among the advantages of computer video communication, we can mention the relatively low cost of operation compared to other communication systems existing today, their versatility, and comparative ease of use. During work, video communication (video conference) subscribers in general case see images of their interlocutor and their own on their monitor screens, which is necessary for visual control established connection. The image is dynamically updated at a speed of up to 15-25 frames/s, depending on the speed (bandwidth) of the communication channel and the channel load. Participants for negotiations use miniature video cameras and microphones with fairly good characteristics.
Speech is digitized for transmission over a communication channel.
The main advantages of computer video communication are the ability to collaborate with documents and integrated information (text, graphics, images received from video cameras, as well as remote launch software applications on the interlocutor’s computer).
Thanks to video communication, the implementation of full-fledged remote offices. Video communication with offices for meetings, operational briefings, and conversations with individual employees will be in great demand. It often happens that an important fifteen-minute meeting requires many hours of standing in traffic jams. Video communication solves these problems, saving money and allowing you to spend your working time as efficiently as possible. What can we say about the situation when it is necessary to organize a meeting of people from different parts of our vast country - then only savings on transportation costs can almost instantly recoup the costs of conducting a video communication session.
In addition to traditional business applications, such as timely meetings, telecomputing support (homeworkers and mobile users), distance learning and personnel certification, video communication can be effectively used in many other situations. For example, when recruiting personnel (recruitment agencies, remote job interviews, etc.); remote medical and other consultations with experts; assessment of various types of damage and destruction (insurance companies); monitoring in case of emergencies and natural disasters; interaction between scientists when conducting scientific research, etc.
By and large, video communication is necessary wherever efficiency is required in analyzing the situation and making decisions, as well as joint work in the mode remote access. This is an indispensable tool in the work of companies with an extensive network of branches. Modern means Video communications provide opportunities for collaboration with data and various applications, right down to signing documents, and existing cryptographic protection means allow you to maintain the confidentiality of the content of video communication sessions.

Video communication itself has no disadvantages as such. However, disadvantages arise as a result of using certain means for organizing video communication:
* high requirements for communication channel capacity;
* low quality Images;
* poor synchronization of image and sound;
* large transmission delay, long reaction time when ordering to view a recording;
* difficulty of maintenance and others.

Skype

Let's look at one of the most popular programs for organizing audio and video communication in computer networks- Skype.

Skype was founded in 2003 by Niklas Zennström and Janus Friis.

Skype is a free proprietary software that provides free encrypted voice communication over the Internet between computers (VoIP), as well as paid services for communication with regular subscribers telephone network.

It is possible to organize a conference call (up to 25 subscribers, including the initiator), transfer text messages and files, as well as video communication (currently, when using a standard client, up to two subscribers, and when using third-party plug-ins, their number is limited only by the channel bandwidth).

Services provided by Skype

Paid services
SkypeOut
SkypeOut allows you to make outgoing calls to landlines and mobile phones in most countries around the world. Payment is per minute.
Calls within Russia
Calls to toll free numbers(such as +1 800 in the USA) are free, and even users who have not paid for the SkypeOut service can use them.

SkypeIn
Allows you to receive phone calls from users of traditional telephone networks. In this case, the participant receives a telephone number. All incoming calls to this number will come to account Skype, and with a positive SkypeOut account, calls can be forwarded to any phone number. As a bonus to phone number Skype provides a free answering machine for the entire time you use the number.

Skype Voicemail
An answering machine that allows you to record incoming messages when the user is offline.

Free services
SkypeCast
Voice chats - allow you to communicate with a large number of Skype users at the same time, create rooms for communication based on interests. SkypeCast has been discontinued since September 1, 2008.

Virtual PBX MANGO OFFICE allows you to receive and make calls not only using regular phones, but also tablets and computers connected to the Internet, and hardware SIP phones.

In today's recipe, we will look at the features of each type of equipment and draw a conclusion about for what purposes which type of equipment is better suited.

Regular phones

Let's start with regular phones. These devices are widespread, reliable and truly familiar. They have good ergonomics and provide decent connection quality.

On the other hand, they can only be connected to the telephone network, which practically eliminates the use of a multi-channel number. The more devices, the more cables to lay. This is not always possible, and when moving an office it can become a real problem.

Another disadvantage is that without additional equipment it is impossible to make outgoing calls from a regular phone through a Virtual PBX (including internal ones). Therefore, such devices are suitable for you only if you just need to receive customer calls, you are not planning to move and there are no problems with organizing a telephone network and laying wires.

Softphones

It is no longer a device, but software. With the help of softphones, you can use a connection via the SIP protocol - an opportunity that regular telephones do not have.

This is a modern communication protocol that allows you to exchange voice messages between two or more remote participants. Its use is completely free, you only need an Internet connection. You can learn more about its capabilities and configuration in one of the previous business recipes.

All incoming calls from landlines, mobile numbers and from other SIP accounts become free. Internal communication for employees will also cost nothing (except for the Starter version of the product).

Softphones are designed for PC and mobile devices. For computers and laptops there is an integrated Virtual PBX. For tablets and smartphones you can find many applications for any platform.

It would seem that this is the ideal option: you can receive and make calls, and even for free! In addition, it is not necessary to be at the workplace. Unfortunately, softphones often do not provide sufficient communication quality, especially for mobile devices.

The program uses the resources of the hardware on which it is installed. Meanwhile, the processor does not have the task of giving the application maximum priority. Thus, the more running programs, the higher the likelihood that there will not be enough resources and the quality of communication will deteriorate.

The PC versions have other drawbacks. Requires a headset connection, if you remove it you may not be able to hear it incoming call, and dialing a number with the mouse on the screen is not at all the most elegant solution.

So, a softphone is not the most convenient tool for processing calls. It helps save on communication costs and provides greater mobility compared to regular phones, but possible problems with communications impose restrictions on its use.

Hardware SIP phones

Based on external features, this device cannot be distinguished from a regular phone. SIP devices are produced by many renowned manufacturers and have different functionality. However, even the simplest SIP phones combine the advantages of regular phones and softphones and are devoid of the disadvantages inherent in the latter. At the same time, they have many additional capabilities.

The economical SIP communication protocol becomes not only profitable, but also of high quality. Codecs are built into the SIP phone that transmit the voices of the interlocutors without distortion or freezes. Echo cancellers and noise suppressors also contribute to this. Communication is no less reliable than using conventional lines and devices.

A SIP phone displays more complete information than a regular phone. For example, at the end of a conversation, a message about the balance is displayed; during internal calls, the first and last name of the interlocutor is shown. In addition, an additional light indication (BLF - Busy Lamp Field) helps to monitor the lines (free/busy) of other subscribers, as well as intercept calls intended for them (for example, if a colleague is not there).

When using SIP phones, no additional work is required to create and update the number database. All company devices will automatically use latest version list of employees, which is loaded from Personal account. The larger the organization, the more resources are saved.

Thus, the use of SIP phones makes communication much easier, more convenient and more profitable. This is the most modern and reliable device for handling calls.

In ours you can choose a SIP phone - from landlines and wireless devices to conference equipment.

Was the recipe useful for you? Express your opinion in the comments!

Write about what else you want to know, and we will talk about it in one of the next issues.

Many IP phone owners prefer this equipment over traditional telephony. That's it a large number of reasons. Below we will discuss the positive features of operating this type of equipment.

➡ More easy installation and customization compared to traditionally designed PBXs. The device uses a large computing power thanks to the integrated processor. It also uses a standard user interface based on the Android OS. Any computer user has the ability to quickly install and configure their phone.

➡ Ease of control. The configuration interface can always be adjusted via the Internet. VOIP phone systems have a configuration interface based on an Internet connection. Other devices that also have Internet access can remotely maintain and configure the phone system. IN standard phones there is no such possibility.

➡ Reduced additional costs. Users can save significantly on international and long-distance calls by using telephone service VOIP. If a telephone system is installed in offices or branches of a company, this will allow you to talk almost free of charge, since a local network is used for conversations.

➡ No need for special telephone wiring. IP phones must be connected to a standard computer network interface. It can be shared by a nearby computer. This means that the user is freed from the hassle of installing and maintaining a wired network for telephone systems. The flexibility to add extensions/new users also increases. If you are located in a new office, where there is no telephone wiring, you can save a lot by just installing a computer network.

➡ There is no binding to a specific supplier. Phones use open standards, the most popular of which is SIP. This means that you can additionally use any telephones or hardware COIP gateways.

➡ Ease of use. Standard phones do not have the ability to use advanced functions, such as conferences. When using IP phones, things are completely different as all functions can be accessed using the pleasant and intuitive Android interface.

➡ A large number of functions in standard packages. Since the phone is software-based, it can be enhanced with a number of new features. As a result, most modern equipment models have a rich set of functions, including voicemail, answering machine, call queue support and so on.

➡ Improved control through better reporting. The software stores information about outgoing and incoming calls, and this data can be sent to specially dedicated servers. Thus, if IP phones are installed in office or administrative buildings, it will be more convenient for managers to monitor the activities of their employees.

➡ More detailed information about the system status in real time. Selected users are able to evaluate the system status in real time using any available web browser.

➡ Possibility of easier implementation of roaming services. Using the SIP protocol, calls can be redirected to anywhere in the world.

A number of additional positive aspects.

The main advantage of IP phones over a traditional softphone is that they are independent hardware capable of operating completely autonomously, rather than being downloaded as software on a computer. This means that even if this moment The computer is not in use, does not work or does not boot, you can still use VoIP communication. For more comfortable use of the device, you can additionally purchase a special headset. In business, you cannot rely on the reliability of a softphone as a whole. It was originally created only for home users or for extremely small businesses.

It is also important to mention such a factor as safety. When making a call, maximum confidentiality of conversations is ensured. Practice shows that hackers are more comfortable hacking a program, thereby stealing voice traffic for themselves, and IP phones use modern security protocols, which are almost impossible to bypass. At least no one has succeeded yet.

Compared with software systems, presented in the form of IP telephony emulators, hardware systems do not require confirmation of login using a login and password. As a result, the opportunity to steal information disappears, since after transmission, links to sent or received data are automatically deleted, and the process itself is protected by advanced protocols.

Long gone are the days when IP telephony was considered an unattainable dream for business. Previously, large operators with multimillion-dollar capital could afford this technology for organizing communications in an enterprise. Today this is an ordinary technology that can be connected by all companies without exception, including representatives of small and medium-sized businesses.

The connection is made using the SIP protocol, ensuring fast data transfer and security. Each call center offering operator services uses the latest developments to improve the quality of services and reduce overall communication costs.

Advantages of Internet telephony

Usage new technology justified by minimal costs and additional benefits, which are the main reason to switch to the new standard.

• Scaling. When using a classic PBX, there is a limitation on the number of numbers and communication points. When using an IP system, scaling up is possible by using new ports, which will not be a costly solution for the business.
• The versatility of technology. Connection can be made different ways, and the work can be done as personal computers, and on laptops.
• Saving. Using several operators will allow you to serve a large number of clients, generating additional income. When ordering several tariffs, the operator will provide favorable discounts.

With proper system design and equipment selection, there will be no distortion or metallic sounds during communication. It is also important to maintain the system so that telephone sales can be carried out at any time.

Comparison of classic telephony and IP systems

When using IP telephony, packets are compressed and transmitted over global network at high speed, ensuring no interference or problems. This is also a cheaper option with obvious advantages:

• Classic telephone lines have excess capacity, while in modern telephony all packets are compressed.
• Everyone has an Internet connection, which reduces overall telephony design and installation costs.
• When making calls over a local network, there is no need to use an external PBX station.

The quality of communication is much better thanks to the constant use of new technologies and capabilities. Autoresponders, forwarding and the use of multiple numbers are created without any problems.