英语翻译H.323 and SIP were developed taking in mind terminals co

英语翻译
H.323 and SIP were developed taking in mind terminals connected directly to IP networks.Both of them consider
connections between IP terminals or between IP terminals and traditional SCN terminals by means of Gateways.The
goal of MEGACO architecture is,in addition,to establish connections between SCN terminals through IP-based
networks.The main idea comes from operators,especially incomers:What about to deploy IP-based core
infrastructure for new investments in the network while providing the same telephone service?.
MEGACO solves this problem mainly by splitting Gateways in three different entities:
q Media Gateway Controller (MGC),which provides the H.323 or SIP signalling and performs mapping
between SCN signalling protocols and IP-based signalling protocols.
q Media Gateway (MC),which provides media mapping and transcoding functions.It terminates SCN (PCM
signal typically) and packet media signals and performs address translation,echo cancellation,playing
announcements,receiving/sending DTMF digits,etc.
q Signalling Gateway (SG),which provides signalling mediation between IP and SCN domains.
In a common scenario,these three elements are intended to be physically separated,providing advantages like,
concentration of many MG in a few MGC controlled by a SG.Figure 1 shows MEGACO architecture.

H.323和SIP是发达国家采取到终端直接连接至IP网络.双方都认为连接的IP终端之间或终端的IP和传统scn终端通过网关.目标megaco体系,另外,为了建立联系scn终端通过IP网络.主要的构想是来自经营者,特别是incomers:什么部署以IP为基础的核心设施,用于新投资的网络,同时提供同样的电话服务?.megaco解决这个问题主要是由分裂门子在三个不同的实体:q媒体网关控制器(mgc) 其中规定的h.323或sip信令和履行之间的映射scn信令协议和基于IP信令协议.q媒体网关(MC)的,提供媒体映射和代码转换功能.终止scn(pcm信号典型)和包媒体信号和执行地址翻译,回波抵消,播放短片,接收/发送的DTMFdigits等问信令网关(SG)的,其中规定信令调停IP和scn域.在一种常见的情况是,这三个要素的本意是分隔开,提供好处想,浓度多毫克数mgc控制的sg.图1显示megaco建筑.