VoIP Gateways Article

In use for more than 40 years throughout the Internet community, Request for Comment (RFC) documents enable developers, researchers and scholars to share information and define new standards and technologies. Now governed by the IETF, RFCs have been vital to development and deployment of VoIP technologies and solutions and remain an important part of the Internet telephony sector.

Beginning in 1995 with development of the H.323 protocol and Session Initiation Protocol (News - Alert) (SIP), two of the building blocks of VoIP, the RFC has been instrumental in the evolution and expansion of IP communications technologies. The two protocols, which handle the call signaling portion of a packetized voice call, have been continuously revised and refined thanks to RFCs and involvement from the greater VoIP community.

The H.248 and Media Gateway (News - Alert) Control Protocols (MGCP) have also been instrumental in VoIP’s evolution and are integral to the proper operation of VoIP gateways. Handling the device control portion of a VoIP call, the protocols have also been developed and refined over the years using RFCs, keeping pace with the evolution of gateways and IP phone systems.

Today, RFCs are prevalent in a number of protocols essential for VoIP calls, including Real-Time Protocol (RTP), which is used globally for transmitting audio and video packets among devices. RTP defines packet order in VoIP calls and also addresses quality issues like delay and jitter. The protocol has evolved to be known as Secure RTP, defined by RFC 3711, allowing for encryption and authentication between communicating devices.

And Web Real-Time Communication (WebRTC) is becoming increasingly prevalent in the VoIP world, enabling a host of communication and collaboration features. The technology is made up of a variety of communication protocols and APIs designed to enable real-time communications over P2P connections. It is currently being standardized by the IETF as well as the W3C (News - Alert), and a number of RFCs are being used in development.

RFCs have clearly been pivotal in defining and growing VoIP technologies along with a host of other Internet-related protocols and technologies. They will continue to be key collaboration tools for developers and academics as protocols and standards evolve.