This protocol is used in the third selection from the ims. It is based on the term media gateway controller mgc and is used between the media gateway and media gateway controller in a. Media gateways that support multipoint conferences might allow three or more terminations per context. All softil products and solutions overcome complex interoperability issues between disparate networks, protocols and devices. Note that other groups may also distribute working documents as internet. A media gateway controller mgc controls one or more media. The well known tcp port for megaco traffic is 2944. The latest call control protocol, megaco, adds to the voip standard problem while seeking to reduce the number of protocols in use. A media gateway controller mgc controls one or more media gateways mg. This manual describes the megaco application, as a component of the. An apparatus and a method for megaco protocol conversion is provided. Megaco protocol plays an important role in the migration to the new releases or from monolithic platform to a network with distributed components. The protocol responds to the requirements documented in rfc 2805.
The megaco application is a framework for building applications on top of the megaco h. Mgcp was the original protocol, which evolved into megaco. In all these call scenarios emphasis is given on the megaco protocol messages rather than the remaining entities. Megaco is a signaling protocol that enables switching of voice, fax and multimedia calls between the pstn and ip networks. The media gateway control protocol mgcp emerged from a group now called the. Us77569b2 apparatus and method for converting megaco. Both protocols are designed for implementation in ip phones that are lower cost than sip or h. Media gateways that offer only pointtopoint connectivity might allow at most two terminations per context. The bestknown media gateway control protocols are currently media gateway control protocol mgcp and megaco h. This controller is called a media gateway controller mgc or call agent ca. The call flow diagrams abstract the protocol messages exchanged between the. Another implementation of the media gateway control protocol architecture is the h. Internetdrafts are working documents of the internet engineering task force ietf, its areas, and its working groups. Megaco instructs media gateways mg to connect streams coming from outside a packet network on to a packet stream such as rtp.
Call agents are external control devicesin a voice system that have complete control of the. Us20060109862a1 apparatus and method for converting. Megaco and sip internetworking columbia university. The megaco working group has identified a large number of corrections. A type of gateway that provides a user to network interface uni such as isdn.
Subsequent annexes were sequentially numbered in the series, e. In such environments, signaling logic is located on media gateway controllers mgcs also known as call agents or softswitches and media logic is located on media gateways mgs. It is based on the term media gateway controller mgc and is used between the media gateway and media gateway controller in a voip network. The media gateway control protocol architecture and its methodologies and programming interfaces are described in rfc 2805 mgcp is a masterslave protocol in which media gateways mgs are controlled by a call control agent or softswitch. The bestknown media gateway control protocols are currently media gateway control protocol mgcp and megacoh. Sip2 session initiation protocol is a peertopeer protocol and is used for establishing multimedia.
Introduction this document describes the megaco protocol for controlling media gate ways from external call control elements called media gateway controll ers. After this the user is free to participate in any further calls. This performs the same functionsas media gateway control protocol,but its a newer protocolthat uses different commands and processes. Internet draft megaco protocol april 16, 1999 consensus on several major issues. Databases store connection information between the objects. Rfc3525 gateway control protocol version 1 megaco version 2 iana megaco assignments. A new protocol has been standardized by the ietf megaco working group working together with itut study group 16, which has been published as both a standardstrack rfc and itut recommendation h. Public packages must be given serial numbers in the range 0x0001 to 0x7fff. The implementation of h248 megaco in seagull conforms to h248 standards, ascii form asn. Megaco this chapter is an overview of the media gateway control protocol megaco version 1 rfc3525, also known as h. The protocol defines a means of communication between a media gateway, which converts data from the format required for a circuitswitched network to that. Multimedia protocol stack media transport quality of service measurement reservation link network signaling physical transport rtsp rsvp h. Megaco is indicated in sctp by a payload protocol id of 7. The serial number will be used to identify the package in the binarycoded version of the megaco h.
Megaco basics introduction communications protocols. Ietf which calls the protocol megaco itu which calls the protocol h. The mgc may underspecify a parameter by providing a loose specification. The megaco media gateway control protocol, rfc 3015 also published as itut recommendation h. Us20060109862a1 apparatus and method for converting megaco. The megaco application is a framework for building applications on top of the megacoh. Session setup, termination, changes aarbitrary services built on top of sip, e.
Media gateway control protocol mgcp, also known as h. Mgcp, described as informational rfc 2705, has been widely deployed. Though ip telephony may well be the springboard for the kinds of new, enhanced voice and data services that carriers crave, deployment has been slowed by lack of or too many. Media gateway controllers use mgcp megaco to control the way media gateways set up multimedia transmissions. The call flow diagrams abstract the protocol messages exchanged between the mg and the mgc. Pdf in this paper, we describe the opnet implementation of megacoh. Mgcp and megaco gateways between ip telephony and pstn. The present invention relates to an apparatus and a method for converting megaco protocol. Citeseerx document details isaac councill, lee giles, pradeep teregowda. Note due to the nature of h248 one scenario contains several h248 transactions with multiple transactionids, seagull supports only client scenarios. The binary encoding is based on basic encoding rules ber description of the protocol and text encoding is based on augmented backusnaur form abnf description. The general base architecture and programming interface was originally described in rfc 2805 and the current specific megaco definition is itut. With the network protocol it can control each specific port on a media gateway.
The megaco group worked on the evolution of the mgcp protocol till the revision 3 of this protocol, which was released on 1 st feb 1999, but abandoned the effort due to some shortcomings of the protocol and more acceptance of another competing protocol mdcp by itut. The semantics of the protocol has jointly been defined by two standardization bodies. Mgcf to release a tdm termination at the tmgw towards the pstn and free all. This document is an internetdraft and is in full conformance with all provisions of section 10 of rfc2026. Ip multimedia concepts and services, second edition book. The maps megaco conformance is designed with sample test cases, which equips the tool to act as mgc testing the functionality of the media gateway for megaco protocol valid and invalid behavior. Megaco is listed in the worlds largest and most authoritative dictionary database of abbreviations and. Looking for online definition of megaco or what megaco stands for. Megaco basics introduction free download as powerpoint presentation. There are a lot of possible scenarios for usage of megaco protocol.
High level description of the protocol this section describes the model and main concepts upon which the megaco protocol is built. Maps megaco protocol emulatormegaco protocol emulation. Megaco protocol version 1 with corrections status of this. In case of dispute, the reference shall be the printing on etsi printers of the pdf version kept on a specific network drive. Use of megaco visavis mgcp to build a gateway solution. For instance, the properties of a media flow on the mg can be set by the mgc by including the appropriate descriptor in a command.
A syntactic element of the protocol that groups related properties. Electra elite ipk megaco station hardware, installation. The mgc is free to not employ digit maps, and to request an event notification. Mastermgc issues commands to send and receive media from addresses, generate tones, and to modify configuration. Media gateway controllers use mgcpmegaco to control the way media gateways set up multimedia transmissions. Several call flow scenarios between the mgc and mgs were simulated to verify the implementation. Maps receives registration requests from mg dut third party gateway and initiates the call flow. Xplico xplico is a network forensic analysis tool nfat. Ip multimedia concepts and services, second edition. This packetcable specification is a cooperative effort undertaken.