In order for the devices (telephones, switchboards etc.) used for making calls over the internet to communicate with each other properly, they must use the same protocol. The reference standard in this field is the SIP (Session Initiation Protocol) protocol. This manages the communication between two parties, and its capacity grows in proportion to the number of people that make use of the service. The protocol is widely used in the business world and it also allows the transfer of audio and video files. SIP has therefore overtaken the much slower H323. This protocol can be used with various systems, making it accessible to everyone. ATAs, and personal computers, which are very similar to VoIP telephones, convert electrical signals into IP data.
Their main functions are:
This type of protocol can be used for client servers, it can be extended, and it does not depend on the transport sector. It can support media identification, call notification, session transference, and invocation of services. Usually it is combined with the IETF protocol for complete multimedia capability. In reality, the scheme reproduces an endpoint, and when it is used as a server it listens to requests and performs them if possible.
This type of protocol allows you to completely satisfy any kind of communication need through the use of the internet, because it conveniently permits the transfer of audio and video, as well as making calls. When the system receives an incoming call it is able to identify whether the user is listed among the contacts, otherwise it identifies the call number. In the course of a conversation, it invites people who are online to a session and therefore also enables videoconferences to be held. At the end, the session can be terminated or a new connection can be made. This system is recommended for those who use telephone services through the computer on a professional basis, to guarantee them a complete service, and to satisfy every professional requirement.