The Yoid project aims to develop scalable host-based distribution protocols which are layered over reasonably constructed tree topologies. The trees are constructed by the participating hosts and may use either native IP multicast, unicast tunnels, or a combination of both. Unlike the MBone, which is constructed using both native multicast and tunnels, Yoid is purely a host-based routing infrastructure.
The Yoid design accepts the realities of the current Internet. It assumes that IP Multicast has limited deployment, especially in the wide area. It also assumes that the participating hosts may be behind fiirewalls and/or NATS and thus global IP addressing of all hosts may not be practical.
Yoid is composed of three major parts: addressing , transport protocols, and tree management. The Yoid Identification Protocol (YIDP) provides a foundation for host addressing within the context of agiven Yoid group. The Yoid Distribution Protocols (YDP) are a family of transport protocols including realtime, non-realtime, reliable, and non-reliable functionality. Finally, the Yoid Tree Management Protocol (YTMP) is responsible for tree construction and management.
In some sense, the Yoid ideas reflect the history and current state of Internet content distribution systems and multiparty conferencing infrastructures. Netnews, with it's NNTP protocol, is probably the most widely known and successful host -based content distribution system. Similarly, the MBone is widely recognized as provided a testbed for the development of the current generation of multiparty conferencing tools. The most active areas of content distribution systems today are focussed on WWW caching infrastructures, instant messaging, and the non-realtime distribution of audio and video content (e.g. Napster). So where does Yoid fit into this puzzle? It is envisioned that Yoid could provide the common "middleware" for all these types of host-based content distribution systems and multiparty conferencing tools.
To demonstrate the utility of Yoid, this project will provide a number of content distribution and multiparty conferencing tools ported to the Yoid middleware. Please check back regularly for status of the available of the Yoid software releases as well as ports of commonly used tools.
Yoid is currently funded by DARPA under contract number F30602-00-2-055.
Earlier research work on Yoid was funded by NTT Software Labs in Tokyo
as the Yallcast project.
Yoid Software (release 1.0)