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The Tenet Group

University of California, Berkeley
and International Computer Science Institute

Recent and Current Research

May 1995

1. Introduction

The Tenet Group was formed in September of 1989 at the University of California at Berkeleyand at the International Computer Science Institute (ICSI, also in Berkeley) to perform research in high-speed computer networking. The focus of the group is on the design and development of real-time communication services, and on network support for continuous-media applications.

In its real-time communication work, the group emphasizes mathematically prova ble (but not necessarily deterministic) performance guarantees, contractual relationships between client and service, general parameterized user-network interfaces with multiple traf?c and QOS (quality of service) bounds de?nable overcontinuous ranges, and large heterogeneous packet-switching networking environments. The Tenet solution to the guaranteed-performance problem was one of the very ?rst approaches based on admission control and rate control that were proposed and fully speci?ed. To our knowledge, it is the ?rst solution implemented and fully operational on a wide-area network.

The Tenet Group has participated in three major multi-institution research projects, twoofwhich have recently completed their mission: BLANCA, Sequoia 2000, and BAGNet. The BLANCA project was part of the Gigabit Testbed Initiative ,which was sponsored by the Corporation for National Research Initiative sand supported by the National Science Foundation and by the Advanced Research Projects Agency. The BLANCA project of?cially started in May 1990, and included AT&T Bell Laboratories, the universities of California, Illinois, and Wisconsin, Rutgers and Columbia University,and a fewresearch institutes, among which is ICSI. The goal of BLANCA was to design and build twowide-area ATM-based testbeds called Xunet 2 (at 45 Mbps) and Xunet 3 (at 622 Mbps), and demonstrate on them several applications requiring high-speed networking. Xunet 3West, which connected the U.C. Berkeleycampus to the Lawrence BerkeleyLaboratory,was based on HIPPI instead of ATM, due to the earlier availability of HIPPI equipment. Most applications were of the scienti?c visualization type and required the transmission of image sequences and/or video streams. The sequences or streams were to be browsed, stopped, and played forward or backward at speeds slower or faster than the nominal one by scientists at sites far from those where the sequences or streams are generated or stored. Wo rk is nowcontinuing on Xunet 2, and the port of the Tenet Suite 1 to it has almost been completed.

Sequoia 2000, the second major initiative inwhich the Tenet Group has participated, aimed at building high-speed storage and communication facilities for global-change scientists at remote locations, allowing these scientists to visualize and browse sequences of digitally represented satellite maps and other large sets of data to be used in earth science research. Project Sequoia 2000, the sequel to Project Athena, was aw arded in July 1991 by the Digital Equipment Corporation to the Unive rsity of California system; its network design and research activities took place at U.C. Berkeleyand U.C. San Diego. The Sequoia 2000 network (S2Knet), which is still in existence, connects at T3 speed (45 Mbps) the Berkeleycampus to the Davis, Santa Barbara, Los Angeles, and San Diego campuses, as well as to the Scripps Institution of OceanographyinSan Diego and the state'sDepartment of Water Resources near Sacramento.

The testbed for the third project, BAGNet (the Bay Area Gigabit Network), has only recently been installed. BAGNet connects ?fteen top computing research organizations located in the San Francisco Bay Area; the organizations have obtained support for ATM SONET services from CalREN (California Research and Education Network), a foundation established by Paci?c Bell. These services are to be used for a number of collaborative m ultimedia applications, the ?rst of which to be implemented will be a "teleseminars" facility.The infrastructure at both U.C. Berkeleyand ICSI has a local SynOptics ATM switch with 16 155-Mbps ?ber ports, providing ATM all the way to the workstations.