IP Telephony (VoIP)

IP Telephony or Voice over IP is the technology that enables the transmission of auditory fragments over the Internet using the Internet Protocol. While data and information has been until now the most prevalent application in information systems, the transfer of voice over the same infrastructure has generated great expectations for the savings that it represents.

Traditional telephony technology is called Circuit-Switching and involves the opening of a permanent digital end-to-end channels to establish communication. This mechanism results in high resource consumption, because a conversation is not carried simultaneously by both parties. To decrease unused resources voice can now be transmitted over Internet based on a technology called Packet Switched.

Nowadays, there are two protocols for transmitting voice over IP, both define how such devices can communicate with each other, and includes specifications for audio codecs. An audio codec converts an analogical audio signal to a digitized one and vice versa. H.323 is the standard established by the International Telecommunication Union (ITU) which comprises an highly complex and extensive protocol, which also include voice over IP, provides specifications for video-conferencing and real-time applications, including other variants. Session Initiation Protocol (SIP) was developed by the IETF (Internet Engineering Task Force) specifically for IP telephony, which in turn takes advantage of other existing protocols to handle part of the conversion process, which is not applied in H.323 and that defines its own base protocols.

IP telephony Software

The potential savings of resources, to reuse existing data infrastructure - the Internet itself - and transmit voice over it, has produced a number of applications and products designed to take advantage of this technology. In the form of specialized equipment to act as PBX (Private Branch Exchange) or switches, software to be installed in a retrieval system, or in applications such as" Messenger "for personal use on PC, using Voice over IP is broad. Some developments based on Voice over IP are Asterisk which is a free software VoIP PBX, Skype is an application style "Messenger" PC that uses Voice over IP and Vonage which it a telephony service provider based solely on Voice over IP.



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VoIP suggestions

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