D079 University College London Peter T. Kirstein Department of Computer Science Gower St London UK WC1E 6BT +44 171 380 7286 +44 171 387 1397 p.kirstein@cs.ucl.ac.uk Jon Crowcroft Department of Computer Science Gower St London UK WC1E 6BT +44 171 380 7296 +44 171 387 1397 jon@cs.ucl.ac.uk Supporting Internet Multicast Multimedia. http://www.cs.ucl.ac.uk/staff/jon/arpa/arpa.html The purpose of the proposed research project is to develop novel mechanisms for supporting and utilising Internet multicast: Mechanisms for supporting multicast routing protocols such as core placement strategies for CBT and PIM, Quality of Service path selection in multicast tree formation, and unicast support for reverse path calculation; Mechanisms for utilising multicast capability in applications such as feedback control in a multicast environment, management of applications in a multicast group, and reliable multicast transport; Mechanisms for integrating resource management with multicast forwarding, such as interface between forwarding engine and caching issues. Demonstration that the above mechanisms are effective with multimedia applications The work is progressing by specification, implementation and measurement, as well as by simulation using the Berkeley "ns" simulator. We collaborate strongly with specific CAIRN groups both in the specifications and parts of the implementations; we make the implementations and simulator modules freely available to collaborators.

We implemented low-level traffic version of Scaleable Reliable Multicast tool -used in the Network Text Editor (NTE); [M. Handley et al: Network Text Editor, To be presented in SIGCOM ?97].

We have developed B-MART - a bulk transfer multicast protocol, being proposed for pre-loading web mirror sites, and VRML world databases. We have made both an implementation and simulations. [Vicisano et al: One-to-Many Reliable Bulk-Data Transfer in the Mbone, Third International Workshop on High Performance Protocol Architectures HIPPARCH '97 Uppsala, Sweden, June 12-13, 1997]

We completed the Session Directory, and Invitation protocols without the incorporation of security, together with releases of implementations. [M. Handley: Session Invitation Protocol, Internet Drafts draft-ietf-mmusic-sap-sec-01.txt ; M. Handley: Session Directory Announcement Protocol, draft-ietf-mmusic-sap-sec-02.txt] We completed a second draft of the Session Directory Security Addendum, which included mechanisms for using both symmetric and public key encryption for authenticating and making private announcements. We released an early implementation with symmetric encryption. [P Kirstein et al.: Specification of Security in SAP Using Public Key Algorithms, Internet Drafts draft-ietf-mmusic-sap-sec-01.txt.]

We have released a first version of a filtering and transcoding gateway. This includes audio mixing, video switching, transcoding of audio (with redundancy against loss). The current version does not include stream synchronisation, but does allow support for lower bandwidth links (hence the functionality provided); this makes it suitable for providing access to ISDN and mobile users. [ P. Kirstein et R. Bennett: Recent Activities in the MERCI Conferencing Project, Proc. JENC 8, Edinburgh, May 12-16, 1997]

We have brought into service the direct ATM link between UCL and CAIRN with the CAIRN routing software. This allows both much closer Audio and Video Personal collaboration, and direct experimental collaboration with the other DARPA researchers on complementary activities.

RP/Core placement

QoS Multicast forwarding implementation

Add stream synchronisation, configurability, conference bus, integration with SDR, security to the filtering/transcoding gateway.

Add stream synchronisation, ability to playback WB and NTE data from Multimedia Server. Add RSTP support to server.

Complete standard and implementation of privacy enhancements to Session Announcements and Invitations.

Experiment over CAIRN with our multimedia tools over the enhanced transport systems. The specifications are transitioned initially via the mechanisms of the CAIRN multimedia meetings, and other direct collaborations. Wider and more formal transition is via the Internet Research Group and the Internet Engineering Task Force - together with broad promotion using the WWW pages and the availability of all the software produced for down-line loading when it is in an appropriate form. 1 JUL 1997 F49620-96-1-0037 Air Force Office of Scientific Research (AFOSR) Mechanisms for Supporting and Utilising Multicast Multimedia 15 JAN 1996 14 JUL 1998 9677,821 Option1119,026 97 Option1119,026 98 Option293,753 $287,281 $289,951 $-2,670 $181,904 30 JUN 1997 We note that it is currently planned to remove the T1 lines in CAIRN before the end of 1997; it would be disastrous for our activity if this included the ATM line between UCL and DARPA. Ideally we would prefer if this link could be doubled in capacity to a sustained T1.