13-10-2010, 04:29 PM
[attachment=5908]
ABSTRACT
This article needs attention from an expert on the subject. See the talk page for details. WikiProject Law or the Law Portal may be able to help recruit an expert. (November 2008)
Voice over Internet Protocol (VoIP, Voice over IP) is a general term for a family of methodologies, communication protocols, and transmission technologies for delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. Other terms frequently encountered and synonymous with VoIP are IP telephony, Internet telephony, voice over broadband (VoBB), broadband telephony, and broadband phone.
Internet telephony refers to communications services — voice, facsimile, and/or voice-messaging applications — that are transported via the Internet, rather than the public switched telephone network (PSTN). The basic steps involved in originating an Internet telephone call are conversion of the analog voice signal to digital format and compression/translation of the signal into Internet protocol (IP) packets for transmission over the Internet; the process is reversed at the receiving end.[1]
VoIP systems employ session control protocols to control the set-up and tear-down of calls as well as audio codecs which encode speech allowing transmission over an IP network as digital audio via an audio stream. Codec use is varied between different implementations of VoIP (and often a range of codecs are used); some implementations rely on narrowband and compressed speech, while others support high fidelity stereo codecs.
Protocols
Voice over IP has been implemented in various ways using both proprietary and open protocols and standards. Examples of technologies used to implement Voice over IP include:
• H.323
• IP Multimedia Subsystem (IMS)
• Media Gateway Control Protocol (MGCP)
• Session Initiation Protocol (SIP)
• Real-time Transport Protocol (RTP)
• Session Description Protocol (SDP)
The H.323 protocol was the one of the first VoIP protocols that found wide-spread implementation for long-distance traffic, as well as local area network services. However, since the development of newer, less complex protocols, such as MGCP and SIP, H.323 deployments are increasingly limited to carrying existing long-haul network traffic. In particular, the Session Initiation Protocol (SIP) has gained widespread VoIP market penetration.
A notable proprietary implementation is the Skype protocol, which is in-part based on the principles of peer-to-peer networking.
Voice over Internet Protocol
ABSTRACT
This article needs attention from an expert on the subject. See the talk page for details. WikiProject Law or the Law Portal may be able to help recruit an expert. (November 2008)
Voice over Internet Protocol (VoIP, Voice over IP) is a general term for a family of methodologies, communication protocols, and transmission technologies for delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. Other terms frequently encountered and synonymous with VoIP are IP telephony, Internet telephony, voice over broadband (VoBB), broadband telephony, and broadband phone.
Internet telephony refers to communications services — voice, facsimile, and/or voice-messaging applications — that are transported via the Internet, rather than the public switched telephone network (PSTN). The basic steps involved in originating an Internet telephone call are conversion of the analog voice signal to digital format and compression/translation of the signal into Internet protocol (IP) packets for transmission over the Internet; the process is reversed at the receiving end.[1]
VoIP systems employ session control protocols to control the set-up and tear-down of calls as well as audio codecs which encode speech allowing transmission over an IP network as digital audio via an audio stream. Codec use is varied between different implementations of VoIP (and often a range of codecs are used); some implementations rely on narrowband and compressed speech, while others support high fidelity stereo codecs.
Protocols
Voice over IP has been implemented in various ways using both proprietary and open protocols and standards. Examples of technologies used to implement Voice over IP include:
• H.323
• IP Multimedia Subsystem (IMS)
• Media Gateway Control Protocol (MGCP)
• Session Initiation Protocol (SIP)
• Real-time Transport Protocol (RTP)
• Session Description Protocol (SDP)
The H.323 protocol was the one of the first VoIP protocols that found wide-spread implementation for long-distance traffic, as well as local area network services. However, since the development of newer, less complex protocols, such as MGCP and SIP, H.323 deployments are increasingly limited to carrying existing long-haul network traffic. In particular, the Session Initiation Protocol (SIP) has gained widespread VoIP market penetration.
A notable proprietary implementation is the Skype protocol, which is in-part based on the principles of peer-to-peer networking.
