Voice Over IP and VOIP Protocols For Internet Telephony

H.225: Call Signaling and RAS in H.323 VOIP Architecture

NetworkDictionary — Tue, 30 Jan 2007 11:09:55 +0800

H.225.0, a key protocol in the H.323 VOIP architecture defined by ITU-T, is a standard to cover narrow-band visual telephone services defined in H.200/AV.120-Series Recommendations.

H.235: Security for H.323 based systems and communications

NetworkDictionary — Tue, 30 Jan 2007 11:09:59 +0800

H.235 is the security recommendation for the H.3xx series systems. In particular, H.235 provides security procedures for H.323, H.225.0, H.245 and H.460 based systems.

H.245: Control Protocol for Multimedia Communication

NetworkDictionary — Tue, 30 Jan 2007 11:10:02 +0800

H.245, a control signaling protocol in the H.323 multimedia communication architecture, is for of the exchange of end-to-end H.245 messages between communicating H.323 endpoints/terminals.

H.323: Packet-based multimedia communications (VoIP) architecture

NetworkDictionary — Tue, 30 Jan 2007 11:10:04 +0800

H.323, a protocol suite defined by ITU-T, is for voice transmission over internet (Voice over IP or VOIP). In addition to voice applications, H.323 provides mechanisms for video communication and data collaboration, in combination with the ITU-T T.120 series standards. H.323 is one o the major VOIP standards, just as Megaco and SIP.

Megaco / H.248: Media Gateway Control protocol

NetworkDictionary — Tue, 30 Jan 2007 11:10:13 +0800

Megaco/H.248, the Media Gateway Control Protocol, is for control of elements in a physically decomposed multimedia gateway, which enables separation of call control from media conversion.

MGCP: Media Gateway Control Protocol

NetworkDictionary — Tue, 30 Jan 2007 11:10:26 +0800

Media Gateway Control Protocol (MGCP) is a VOIP protocol used between elements of a decomposed multimedia gateway which consists of a Call Agent, which contains the call control "intelligence", and a media gateway which contains the media functions, e.g., conversion from TDM voice to Voice over IP.

NCS: Network-Based Call Signaling Protocol

NetworkDictionary — Tue, 30 Jan 2007 11:10:28 +0800

Network-based Call Signaling, based on the Media Gateway Control Protocol (MGCP), is the VOIP signaling protocol adobted by the CableLab as a standard for PacketCable embbed clients, which is a network element that provides

SAP: Session Announcement Protocol

NetworkDictionary — Tue, 30 Jan 2007 11:10:30 +0800

Session Announcement Protocol (SAP) is an announcement protocol that is used to assist the advertisement of multicast multimedia conferences and other multicast sessions, and to communicate the relevant session setup information to prospective participants.

SCCP: Skinny Client Control Protocol

NetworkDictionary — Tue, 30 Jan 2007 11:10:33 +0800

Signaling Connection Control Part (SCCP), a routing protocol in SS7 protocol suite in layer 4, provides end-to-end routing for TCAP messages to their proper database.

SDP: Session Description Protocol

NetworkDictionary — Tue, 30 Jan 2007 11:10:35 +0800

The Session Description Protocol (SDP) describes multimedia sessions for the purpose of session announcement, session invitation and other forms of multimedia session initiation.

SIP: Session Initiation Protocol

NetworkDictionary — Tue, 30 Jan 2007 11:10:38 +0800

SIP (Session Initiation Protocol) is an application-layer control protocol that can establish, modify, and terminate multimedia sessions such as Internet telephony calls (VOIP).

T.120: Multipoint Data Conferencing Protocol Suite

NetworkDictionary — Tue, 30 Jan 2007 11:10:40 +0800

The ITU T.120 standard is made up of a suite of communication and application protocols, which are designed for multipoint Data Conferencing and real time communication including multilayer protocols which considerably enhance multimedia, MCU and codec control capabilities.

RTCP: RTP Control Protocol

NetworkDictionary — Tue, 30 Jan 2007 11:10:42 +0800

The Real Time Transport Control Protocol (RTP control protocol or RTCP) is based on the periodic transmission of control packets to all participants in the session, using the same distribution mechanism as the data packets.

RTP: Real Time Transport Protocol

NetworkDictionary — Tue, 30 Jan 2007 11:10:44 +0800

The Real-Time Transport protocol (RTP) provides end-to-end delivery services for data with real-time characteristics, such as interactive audio and video or simulation data, over multicast or unicast network services.

G.7xx: Audio (Voice) Compression Protocols (G.711, G.721, G.722, G.723, G.726, G.727. G.728, G.729)

NetworkDictionary — Tue, 30 Jan 2007 11:10:47 +0800

G.7xx, including G.711, G.721, G.722, G.726, G.727, G.728, G.729, is an suite of ITU-T standards for audio compression and de-commpression. It is primarily used in telephony. In telephony, there are 2 main algorithms defined in the standard.

H.261: Video Coding and Decoding (CODEC)

NetworkDictionary — Tue, 30 Jan 2007 11:10:49 +0800

H.261 is video coding standard by the ITU. It was designed for data rates which are multiples of 64Kbit/s, and is sometimes called p x 64Kbit/s (p is in the range 1-30).

H.263: Video Coding and Decoding (CODEC)rk

NetworkDictionary — Tue, 30 Jan 2007 11:10:52 +0800

The H.263, by the International Telecommunications Union (ITU), supports video compression (coding) for video-conferencing and video-telephony applications.

H.264/MPEG-4: Video CODEC For High Quality Video Streaming

NetworkDictionary — Tue, 30 Jan 2007 11:10:57 +0800

The H.264 and the MPEG-4 Part 10, also named Advanced Video Coding (AVC), is jointly developed by ITU and ISO. H.264/MPEG-4 supports video compression (coding) for video-conferencing and video-telephony applications.

COPS: Common Open Policy Service

NetworkDictionary — Tue, 30 Jan 2007 11:10:59 +0800

The Common Open Policy Service (COPS) protocol is a simple query and response protocol that can be used to exchange policy information between a policy server (Policy Decision Point or PDP) and its clients (Policy Enforcement Points or PEPs).

RTSP: Real Time Streaming Protocol

NetworkDictionary — Tue, 30 Jan 2007 11:11:02 +0800

The Real-Time Streaming Protocol (RTSP) establishes and controls either a single or several time-synchronized streams of continuous media such as audio and video. RTSP does not typically deliver the continuous streams itself, although interleaving of the continuous media stream with the control stream is possible.

SCTP: Stream Control Transmission Protocol

NetworkDictionary — Tue, 30 Jan 2007 11:11:04 +0800

Stream Control Transmission Protocol (SCTP) is designed to transport PSTN signalling messages over IP networks, but is capable of broader applications.

SIGTRAN: Signaling Transport Protocol Stack

NetworkDictionary — Tue, 30 Jan 2007 11:11:07 +0800

Signaling Transport (SIGTRAN) refers to a protocol stack for the transport of Switched Circuit Network (SCN) signaling protocols (such as SS7/C7 an Q.931) over an IP network.

TRIP: Telephony Routing Over IP

NetworkDictionary — Tue, 30 Jan 2007 11:11:10 +0800

Telephony Routing over IP (TRIP) is a policy driven inter-administrative domain protocol for advertising the reachability of telephony destinations between location servers, and for advertising attributes of the routes to those destinations.