What is IP-telephony?the Term IP-telephony appeared relatively recently. In literal sense it means “ telephony with transfer through IP - the " protocol;. As the IP protocol (Internet Protocol) is used for work of the Internet, IP-telephony is often connected with the Internet. At the same time IP-telephony can work through any networks on the basis of IP - the protocol. Further I suggest to apply a standard abbreviation of VoIP to designation of IP-telephony (Voice over IP - a voice over IP) which describes an essence of the phenomenon more precisely and eliminates discrepancies when comparing usual telephony and its IP - option.
Usual telecommunication is carried out on a chain “ subscriber - Automatic telephone exchange - subscriber “. Each of subscribers dials to automatic telephone exchange where the special switchboard, having got a number from the telephone set, connects it to other subscriber.
VoIP represents a bit different scheme of work. The subscriber calls on automatic telephone exchange where his speech is numbered and in the coded digital form is transported, for example, to other city by means of IP - the protocol on the Internet. In the city - the addressee there is the return process: the speech signal is decoded and on a usual telephone network is transferred to the subscriber - the recipient. It turns out that subscribers pay only for calls by the city (more true, on the cities), plus not really large sum for the Internet - a traffic. For example, calls to Brazil can manage in the traditional way in 75,66 rub/min., and by means of VoIP - in total in 11,40.
The cost of the trunk call which is carried out in the standard way, and traffic cost for commission of such call on the Internet differ many times. Low cost of service gives rise to popularity which, in turn, leads to bigger profitability of rendering of services of an international telecommunication by means of VoIP. Advantage of trunk calls became the main VoIP engine in masses.
Despite low cost of VoIP, there is a number of problems. When the IP protocol was developed, it was decided that at an overload of channels of transfer routers will just destroy packages which cannot be transferred. It was reflected in VoIP so that if a voice stream simply not “ passes “ from - for congestion of the channel, packages are destroyed and the part of voice information is lost. It causes “ pokhryukivaniye “ and pauses when using VoIP.
VoIP - subscribers can communicate not only among themselves, but also to call subscribers of a usual telephone network and to receive from them calls. For the solution of this task so-called VoIP - locks are used. These are special devices which are capable to be connected to a network of traditional telephony, but at the same time to be also subscribers of VoIP - networks. As installation and service of locks cost money, in most cases their use is paid.
At the accounting of all factors, somehow: reliability, quality and simplicity of payment, you easily can come to a conclusion that “ it`s not worth the trouble “. Especially, when it is necessary to call a little and not often. Use of VoIP is especially effective when it is required to call in large volumes, considering at the same time that the interlocutor on that party will be ready to be reconciled with more poor quality of communication.
One more reason for the growing popularity of VoIP - convenience . It is simple to some people whose number increases to call more conveniently from the computer, than to use stationary phone. There are no doubts that sooner or later VoIP completely will force out wire telephony. A question only in economic feasibility and a technological level of users.
The third reason is covered in the corporate market. The matter is that VoIP can replace traditional telephony, for example, at the level of the enterprise. This technology can quite become alternative office pass - automatic telephone exchange as imeetryad advantages: does not demand separate conducting for phones (uses the existing network), does not demand pass - automatic telephone exchange (to enough start special service on one of servers), allows to enter enciphering of talk, it is easily integrated both with the VoIP networks, and with networks of traditional telephony.
Besides it is possible to carry to pluses of VoIP mobility (communication is everywhere where it is possible to be connected to the Internet), improvement of quality of fax (as both fax protocols, and VoIP - digital technologies), global roaming etc.
As you already understood , VoIP represents rather perspective technology which introduction is already well under way. The low cost of the provided services, without noticeable deterioration in their quality is of special interest for us, for simple consumers. By estimates of a number of expert firms, this technology will develop further, getting rid of the minuses and becoming more and more attractive in respect of cost.
Well and finally - practical advice. If you want to save money, then just compare tariffs of the organizations providing communication services and choose for yourself compromise option by criterion “ price / quality “. In it there is nothing difficult: 2 - 3 experiments with calls to other city and you will find what was looked for.
I wish you good luck in your searches and all good!