IP telephony is a modern way of voice communication in teleinformatic networks, using voice transmission mechanism in the so-called packet type (as is the case with data transmission) and using the same network that is used for data transmission.
Traditional telephony, based on the commutation of the connection uses a separate, dedicated telephone network.
The company, which consists of a distributed branch network and has a wide network that guarantees high quality transmission, will be able to reduce the cost of its telephone bills relatively modestly. Voice service is in this case (also in a long distance relationship) wholly implemented as a Voice-over-IP service. This means that all in-house business calls are free (cost of telecommunication), and communication with the outside world within a given telephone area is a cost of local call.
Savings not directly related to connection charges are also the unification and simplification of ICT infrastructure. In a company that only uses IP telephony, structured cabling for the needs of phones is unnecessary. In the case of a company introducing a new building, for example, this may mean additional, significant savings.
Another issue is the use of subscriber voicemail systems. Traditional panel manufacturers are paying briskly for every gigabyte of disk space used to store voice messages. An analog IP-based system uses the storage space of standard servers, and therefore is significantly cheaper to expand.
It is possible to implement IP telephony from two standards:
This standard provides for server implementations for IP telephony services along with dedicated terminals – IP telephones. It is very important here the speed of installation and the ease of reconfiguring IP telephony compared to traditional telephones. IP phones all configurations including IP address, phone number, keystrokes etc. – download from server. They can be prepared and tested in one place, and the physical installation should be left to the less qualified person working in a remote unit. Thanks to that, for example, installing a company with hundreds of phones across the country can take up to a week, with the involvement of 2-3 engineers who would not even have to leave the Head Office. Telephones sent to local offices were then wired with local power, and the connection consisted of transferring the network cable from the computer to the phone and connecting the computer to a second socket on the phone with a separate cable.
A cheaper solution using existing telephone infrastructure is also possible. Assuming that each branch has a local PABX, it is possible to equip each PBX with a Voice-Over-IP module. After making the appropriate configuration, it will be possible to connect to any number in each branch as with an ordinary extension. This solution avoids the cost of buying IP phones.