MGCP is intended to improve upon the characteristics of H.323 by easily scaling to larger networks. This scaleability is evident from MGCP's protocol, which allows it to function in a distributed environment. MGCP's scaleability avoids the call-control limitations that result from the coupled interactions between H.225 layering and H.323 system control, which some critics say exist in the H.323 specification. Its intent is to define a true telephony gateway without provision for video. MGCPacts as a network element that provides solely for the conversion of audio signals carried on telephone circuits and data packets carried on packet networks.
Synchronized messaging enables coherent commands to the gateways under their control.
The basic constructs of MGCP are endpoints and the connections between them. These basic constructs differ from that of the H.323 model of virtual connections formed by IP packet data flows. Alternatively, the IETF has developed SIP as another Internet conferencing and telephony standard. In addition, SIP provides flexible addressing, including addressing modes that have similarities to e-mail and domain name servers, along with IP addressing. Evident within this sea of acronyms is that as VoIP evolves, QoS issues, as well as costs, will cease to be significant differentiators for VoIP products and services.