By: Zhen Guo
Advisor: Roberto Rojas-Cessa
Department of Electrical and Computer Engineering

Time: 2:00 PM, Wednesday, December 14th, 2005.
Place: Room 202, ECE Center, New Jersey Institute of Technology, Newark NJ. Directions

Abstract

With the rapid development of optical interconnection technology, high-performance switches are required to resolve contentions in a fast manner to satisfy the demand for high throughput and high-speed rates.  Combined input-crosspoint buffered (CICB) switches are an alternative to input-buffered (IB) packet switches to provide high-performance switching and to relax arbitration timing for packet switches with high-speed ports.

This dissertation studies a feedback-based arbitration model, where cell selection is based on the provided service to virtual output queues (VOQs). The feedback-based scheme is named round-robin with adaptable frame size (RRAF) arbitration. Here, it is proved that RRAF achieves 100% throughput under uniform admissible traffic through Lyapunov’s analysis.

Switches with crosspoint buffers are sensitive to the transmission delays, or round-trip times (RTTs). Therefore, the largest RTT value defines the crosspoint buffer size for ports with high-speed rates. However, buffers are expensive in a crossbar as the number of them is proportional to the number of crosspoints. To minimize implementation costs, this thesis investigates how to select the crosspoint buffer size under non-negligible round-trip times and under uniform traffic. With analysis of stability margin, the relationship between the crosspoint buffer size and round-trip time is derived.

Considering that CICB switches deliver higher performance than IB switches and require no speedup, this dissertation investigates the maximum throughput performance that these switches can achieve. It is proved that CICB switches, without speedup, achieve 100% throughput under traffic that follows the Strong Law of Large Numbers, through stability analysis of these switches by using a fluid model and a novel class of arbitration schemes.

In order to give a better insight of the feedback nature of arbitration schemes for CICB switches, a frame-based round-robin arbitration scheme with explicit feedback control (FRE) is introduced. It is shown that the concept of explicitly feedback in a continuous system can be engineered to be stable. This concept is transported to discrete systems, such as cell-based switches, and used to create arbitration schemes that deliver high performance under uniform and nonuniform traffic models.

In addition, this dissertation explores an alternative analysis technique based on control theory to study the stability of arbitration and matching schemes for packet switches, where a continuous system and a control model are used to emulate queuing systems.

Committee Members:
Roberto Rojas-Cessa, Advisor, Assistant Professor, ECE Dept., NJIT
Nirwan Ansari, Professor, ECE Dept., NJIT
Edwin Hou, Associate Professor, ECE Dept., NJIT
Jie Hu, Assistant Professor, ECE Dept., NJIT
Aleksandar Kolarov, Technical Leader, Cisco Systems