I attended the 70th Internet Engineering Task Force (IETF) meeting in Vancouver from 2nd-7th December 2007, funded by a GridNet2 award. This brief report summarises the outcomes of my trip, in accordance with GridNet2 requirements. GridNet2 is funding my continued activities as co-chair of the Audio/Video Transport (AVT) working group, and my work developing standards for real-time collaborative work applications and Network Address
Translator (NAT) traversal. This trip report focusses on activities in those working groups, and my related activities in the IETF, of interest to the UK e-science community. Opinions expressed herein are those of the author, and do not necessarily represent those of the IETF or its working groups.
The AVT working group develops standards for real-time audio/visual data transfer on IP networks. Those standards underpin modern voice over IP, 3G mobile telephony, and video conferencing systems, including the AccessGrid,
VRVS, and similar tools used by the e-science community. I co-chaired both AVT working group sessions at the 70th
IETF meeting. Discussion in the first session focussed on RTP payload formats for layered audio and for scalable, multi-view and 3-dimensional video, and on reporting multimedia quality metrics for performance monitoring and systems management. I was actively involved in these discussions, and in several side meetings in these areas, working to ensure industry proposals are coherent and aligned with the RTP architectural framework.
The second AVT session focussed on use of non-compound RTCP (a draft from Ericsson building on my previous work on multiplexed RTCP), and security of RTP sessions. The security work is gaining large interest, and should provide an infrastructureless mechanism for keying secure RTP sessions. I am again strongly involved, helping to integrate the security mechansisms (i.e Diffie-Helman key exchange) into the RTP framework.
I also chaired a birds-of-a-feather (BoF) session on Self Address Fixing Evolution. One of the key problems in deploying peer-to-peer systems in the current Internet is NAT traversal. This impact multimedia conferencing, telepresence, and VoIP systems – which is my main interest in this work – but also directly affects Grid Computing systems which must transfer files and data or execute jobs across organisational boundaries. The purpose of this
BoF was to explore the limitations of existing protocols in this area, and to gauge interest in possibly chartering future work in the IETF to resolve some of the issues raised. Discussion was lively, and provided a great deal of input to the area directors.
Finally, I continue to participate in the Transport Area Directorate of the IETF, advising the area directors on transport aspects of real-time media protocols.
Funding from GridNet2 continues to be essential for this work, and I believe the outcomes of this work will be of interest to the e-Science community, and will underpin future developments in Grid toolkits and collaborative work environments.