Past Projects at the IBM T.J. Watson Research Center


The plaNET project was among the first projects to design and implement Gigabit networking technology, including one of the first high speed packet switch, the plaNET switch, and a comprehensive framework for call admission and congestion control. The project was primarily carried out as part of the AURORA Gigabit testbed, where I first had the opportunity to collaborate with Profs Dave Farber and Jonathan Smith. One of the outcomes of this work was actually the development of the concept of equivalent or effective bandwidth, that has since then been used in numerous systems and products as a base for call admission.

Integrated Switch Router (ISR)

The ISR project focused on the design and implementation of a QoS capable router and investigated the possibility of combining switching (layer 2) and routing (layer 3) forwarding approaches to achieve this goal. The project involved about a dozen people who designed and implemented a complete system including deep adapters supporting layer 3 forwarding and layer 2 cut-through for flows with QoS requirements, sophisticated scheduling and buffer management capabilities using the CHARM chip, and a full implementation of the RSVP protocol that was "enhanced" to also support the establishment of layer 2 cut-through circuits in a fashion similar to what is proposed today for the MPLS IETF standard.

QoS Extensions to the OSPF Protocol

This work was aimed at extending the OSPF protocol to support the ability to compute paths capable of satisfying specific QoS requirements, e.g., bandwidth or delay guarantees.  There were two main thrusts to this work. The first was to design and implement the necessary protocol extensions to the OSPF protocol, so that QoS capable paths could be computed. The second was to gain a better understanding of the cost vs performance trade-offs that QoS routing involves, i.e., what factors affect the complexity of QoS routing and how do they translate into greater network performance? Some of the findings from this work were presented at Sigcomm'98 in a paper entitled "Quality of Service Routing: A Performance Perspective." Additional experimental results on the implementation of QoS extensions to OSPF on the GateD platform are described in a report entitled "Implementation and Performance Measurements of QoS Routing Extensions to OSPF" . Up-to-date information on this work including the release of code based on the gated platform and implementing the QoS extensions described in an experimental RFC (RFC 2676) entitled "QoS Routing Mechanisms and OSPF Extensions," can be found on the QoS-OSPF page.