Glossary

The 3GPP, a body that comprises wireless infrastructure, handset, and service providers throughout the world, has defined the H.324M Protocol as the videoconferencing standard for circuit-switched 3G networks. H.324M is an umbrella protocol defined by the ITU to enable multimedia communication over mobile networks. This protocol defines multimedia communication algorithms ...

Abstract Syntax Notation One, a language used to describe the complex data structures independently from the underlying hardware. ASN.1 is a standard developed by the ITU-T and is described in X.680-X.694. ASN.1 is used in the H.323 and 3G-324M Recommendations in order to describe all the messages that are exchanged ...

BER (Basic Encoding Rules) is an encoding specification for ASN.1 definitions. It is defined in ITU-T X.690 standard. BER notation is based on TLV, where each element is encoded with its specific type, length of the value and the value itself. BER is not usually used in VoIP related protocols ...

BFCP is a protocol which allows control of a virtual conference floor in VoIP multimedia conferences. BFCP is specified in RFC 4582. A floor is a shared conference resource, which is available only to a single participant at a time. If the ability to present is considered such a resource, ...

Diameter is an extensible messaging protocol defined by RFC 3588, enabling Authentication, Authorization and Accounting within and across IP multimedia networks that rely on secure and reliable transports. The protocol evolved from the RADIUS protocol but is much more scalable and well defined, has fail-over capabilities, runs over secure TCP/SCTP ...

E.164 is an ITU-T standard that defines an international numbering plan. E.164 numbers include country codes, national destination codes and subscriber numbers. E.164 is one of the ways in which H.323 endpoints can use.

H.239 is an ITU-T recommendationfor role management and additional media channels for H.3xx-series terminals. Sets forth a way to have multiple video channels (e.g., one for conferencing, another for presentation) within a single session (call). H.239 is widely used by H.323 video conferencing systems to support dual video mechanisms, where ...

H.245 is an ITU-T standard that defines a control protocol for multimedia communication.H.245 passes its control information messages over a reliable channel between two entities that are engaged in a multimedia call (voice only or voice and video). H.245 messages are defined using ASN.1 and are encoded using PER.H.245 starts ...

H.281 is an ITU-T recommendation describing how a far end camera control system for H.320 terminals can be operated.H.281 has been adopted for the use of H.323 as well as part of the definition of H.323 Annex Q.

H.323 is an “umbrella” Recommendation by ITU-T , defining protocols that support multimedia communication sessions over packet networks. H.323 provides means for call signaling and control, media transport and control and bandwidth control for both peer-to-peer and multi-party sessions. H.323 was published in November 1996, focusing mainly on video conferencing ...

H.323 Annex Q defines how far end camera control is acheived in the H.323 standard.

H.324 is a circuit switched video telephony protocol specification defined by the ITU and adopted by the 3GPP for mobile video telephony. To learn more about it, see 3G-324M.  

Annex K is a call acceleration technique in 3G-324M. It is also known as MONA (Media Oriented Negotiation Acceleration).It is a set of 3 different techniques for call acceleration which are designed to reduce call setup times to below 1 second.Annex K is designed as a set of 3 classes, ...

IP Multimedia Subsystem (IMS) is a technology that defines how to set up advanced services for 3G cellular networks. IMS offers a flexible vehicle for quickly deploying new revenue-generating applications in the network. An IMS core network allows a service provider to deliver identical IP services to fixed and mobile ...

An entirely digital telephone network that allows both data and voice communications over the same line. ISDN replaces the old analog local loop and operates at significantly faster speeds than the traditional telephone service.

LTE, or Long Term Evolution, is the next generation cellular network, which is sometimes marketed as 4G. The main difference between LTE and previous cellular network architectures is the fact that it is an all-IP network, with not circuit switching capabilities. Voice calls and SMS services over an LTE network ...

Short for Multi-Protocol Label Switching, MPLS is an IETF initiative integrating Layer 2 network links information (such as bandwidth, latency, link utilization) into Layer 3 (IP) within an autonomous system (or ISP) in order to improve and simplify IP-packet exchange. MPLS gives network operators the flexibility to divert and route ...

MSRP stands for Message Session Relay Protocol and is defined by IETF in RFC4975 and RFC 4976. MSRP is open text-based protocol which allows transmission of the media content of various size in the instant messaging scenarios via established session. MSRP can be used for text and file/image transfer in ...

PER (Packed Encoding Rules) is an encoding specification for ASN.1 definitions. It is defined in ITU-T X.691 standard. PER is optimized for size, where ASN.1 messages gets encoded into a relatively small size when sent over the network. For example, a boolean field in PER will get encoded using a ...

Packet-Switched Streaming offers the basic building block for streaming services using IP over cellular networks. It is based on 3GPP and 3GPP2 specifications (TS 26.233, TS 26.234, and TS 26.244). At the heart of the PSS specification lies the RTSP protocol. Interoperability of PSS is being handled by the IMTC.

Q.931 is an ITU-T standard specification for basic call control. Q.931 is used in many networks such as ISDN. It is also part of the H.323 specification, where it is partially used. It is a message exchange protocol dealing with call setup procedures. Q.931 messages are encoded using a form ...

RCS (Rich Communication Suite) is an initiative of the GSM Alliance (GSMA). RCS aims to speed up and facilitate the adoption of applications and services that provide an interoperable, convergent, rich communication experience based on IMS. From the end-user’s perspective, RCS facilitates services such as instant messages, buddy lists and ...

RTCP stands for Real Time Transport Control Protocol and is used in conjuction with RTP. It is defined along with RTP in RFC 3550.The main purpose of RTCP is to gather and report statistical information about the media sent over RTP - information that can be used by the sender ...

Real Time Transport Protocol (RTP) is an IP protocol that supports real-time transmission of voice and video. It is widely used for IP telephony.RTP is defined in RFC 3550 which obsoletes an older version of this protocol in RFC 1889.RTCP is a companion protocol that is used to maintain QoS.RTP ...

RTSP stands for Real-Time Streaming Protocol.RTSP is an application-level protocol for controlling the delivery of real-time data, such as audio and video. The RTSP protocol is coupled with data transport protocols such as RTP; while real-time data is transported over RTP, the flow ofthe data is controlled by RTSP.As a ...

Stream Control Transmission Protocol (SCTP) is a transmission layer, such asTCP or UDP.SCTP is a connection-oriented protocol (such as TCP), that deals with datagrams (such as UDP) rather than byte streams (such as TCP).Unlike TCP, SCTP provides a number of functions thatare critical for telephony reliable signaling transport over a ...

SDP (Session Description Protocol -RFC 4566) is the protocol used to describe multimedia session announcement, multimedia session invitation, and other forms of multimedia session initiation. A multimedia session is defined, forthese purposes, as a set of media streams that exist for a duration of time.SDP packets usually include the following ...

SIMPLE stands for Session initiation protocol for Instant Messaging and Presence Leveraging Extensions. SIMPLE is defined by IETF and uses another IETF protocol, SIP as a core. SIMPLE is an open standard which allows development of interoperable Presence and Instant messaging applications. SIMPLE protocol functionality is based on the number ...

The Session Initiation Protocol (SIP) is a signaling protocol for initiating, managing and terminating voice and video sessions across packet networks. Borrowing from Internet protocols, such as HTTP and SMTP, SIP is text-encoded and highly extensible. SIP can be extended to accommodate features and services such as call control services, ...

The SIPconnect Technical Recommendation is an industry-wide, standards-based approach to direct IP peering between SIP-enabled IP PBXs and VoIP service provider networks.BenefitsThe implementation of the SIPconnect standard benefits many participants in the delivery of voice communications.For end users in the small business or large enterprise, SIPconnect eliminates, or greatly reduces, ...

The Session Traversal Utilities for NAT (STUN) protocol allows entities behind a Network Address Translators (NAT) to learnthe address bindings allocated by the NAT, to keep those bindings open, and communicate with other STUN-aware entities to validate connectivity and vitality. The STUN protocol was developed as a solution to some ...

T.120 is an ITU-T standard that was designed to create a self-sufficient set of data collaboration tools, which may be used either as standalone or in the content of a multipoint videoconference. T.120 protocol stack architecture While T.120 provides rather advanced features, it also comes with great complexity and found ...

TLV (Type Length Value) encoding is a general technique of encoding messages to a network representation. In TLV, each field is designated a type, which gets encoded. Then the lengh of the value is added and after that the value of the field itself. TLV is used in Q.931 encoding.

VCC is a technology for persistent calls handovers between different types of access networks. It has been adopted by the 3GPP to allow handing over mobile voice calls from circuit switched networks to packet switched ones. IMS is used for VCC implementations for the packet switched network side.

VoLTE is a GSMA specification also known as GSMA PRD IR.92.VoLTE started as an initiative by a group of companies known as One Voice.VoLTE focuses on specifying how voice, SMS and rudimentary supplementary services are signaled over LTE. The signaling selected by LTE is IMS.The test specificaiton document and interoperability ...

WNSRP (Windowed NSRP) is a call setup reduction technique used in 3G-324M. WNSRP speeds up the handling of H.245 messages in 3G-324M by using a windowing mechanism that can send several different messages concurrently. It ensures thatall messages are received and that they appear in the correct order. WNSRPworks in a way ...

XCAP stands for XML Configuration Access Protocol and it is defined by IETF in RFC4825. The purpose of XCAP is to allow manipulation of user-specific data via common HTTP mechanisms. One of important applications for XCAP is management of Presence and IM information in the SIP communication network, where it ...

XDM stands for XML Document Management and is an open standard defined by Open Mobile Alliance (OMA). Full specification can be found here. XDM is enabling interoperable Presence implementations (i.e. SIMPLE), and is used to access and manipulate various XML document stored across the network, all with established identity, authorization ...

The Extensible Messaging and Presence Protocol (XMPP) is an open standard for real-time communication. In a sense, XMPP is a way to route XML data between entities.XMPP is being standardized within the IETF. The core of the XMPP protocol is publised as RFC 3920.The core XMPP protocol offers the basic ...