These sites provide useful information about the standards employed in the IP telephony arena:

CableLabs
Cable Television Laboratories, Inc. (CableLabs®) is a membership organization consisting of cable television system operators serving cable subscribers in the U.S., Canada, Mexico, and South America. Its mission is to plan and to fund research and development projects; to transfer relevant technologies to member companies and industry suppliers; and to serve as a clearinghouse in providing technological information to its members..




DSL Forum
The DSL Forum was formed in late 1994 to help telephone companies and their suppliers realize the enormous market potential of DSL. Our assistance comes in two forms -- technical and marketing. The Forum's marketing programs attempt to uncomplicate DSL's inherent technical complexity and sprread the news. The Forum's public output therefore mixes the tutorial with the promotional.




European Telecommunications Standards Institute
The European Telecommunications Standards Institute is a non-profit organization whose mission is to produce the telecommunications standards that will be used for decades to come throughout Europe and beyond.



The Internet Engineering Task Force
The IETF is a large open international community of network designers, operators, vendors, and researchers concerned with the evolution of the Internet architecture and the smooth operation of the Internet. It is open to any interested individual.





International Telecommunication Union
The ITU, headquartered in Geneva, Switzerland is an international organization within which governments and the private sector coordinate global telecom networks and services.



The Object Management Group
The OMG was formed to create a component-based software marketplace by hastening the introduction of standardized object software. The organization's charter includes the establishment of industry guidelines and detailed object management specifications to provide a common framework for application development.