The following papers address topics related to my research on communication systems and protocols for high-speed networks:
A communication subsystem consists of protocol tasks and operating system mechanisms that support the configuration and execution of protocol stacks composed of protocol tasks. To parallelize a communication subsystem effectively, careful consideration must be given to the threading architecture. The threading architecture binds processing elements with the protocol tasks and the messages associated with protocol stacks in a communication subsystem. This paper makes two contributions to the study and application of threading architectures. First, it reports performance results from empirical comparisons of two protocol stacks (based on the connectionless and connection-oriented transport protocols UDP and TCP) using different threading architectures on a 20 CPU multi-processor platform. The results demonstrate how and why different threading architectures affect performance. Second, the paper provides guidelines based on these results that indicate when and how to apply appropriate threading architectures.
This paper describes research on new methods and architectures that enable the synergistic combination of IP and ATM technologies. We have designed a highly scalable gigabit IP router based on an ATM core and a set of tightly coupled general-purpose processors. This aItPm (pronounced ``IP on ATM'' or, if you prefer, ``IP-ATTEM'') architecture provides flexibility in congestion control, routing, resource management, and packet scheduling.
The aItPm architecture is designed to allow experimentation with, and fine tuning of, the protocols and algorithms that are expected to form the core of the next generation IP in the context of a gigabit environment. The underlying multi-CPU embedded system will ensure that there are enough CPU and memory cycles to perform all IP packet processing at gigabit rates. We believe that the aItPm architecture will not only lead to a scalable high-performance gigabit IP router technology, but will also demonstrate that IP and ATM technologies can be mutually supportive.
Message-based process architectures are widely regarded as an effective method for structuring parallel protocol processing on shared memory multi-processor platforms. A message-based process architecture binds one or more processing elements with data messages and control messages received from applications and network interfaces. In this architecture, parallelism is achieved by simultaneously escorting multiple messages on separate processing elements through a stack of protocol tasks. This paper reports performance results from empirical comparisons of a connection-oriented TCP/IP protocol stack implemented using two different parallel message-based process architectures. These performance experiments measure the throughput, context switching, and synchronization exhibited by the two process architectures on a shared memory multi-processor platform. The experimental results demonstrate the extent to which the selection of a parallel process architecture affects protocol stack performance.
Providing end-to-end gigabit communication support for bandwidth-intensive distributed applications requires high-performance transport systems. This paper describes and classifies transport system mechanisms that integrate operating system resources (such as CPU(s), virtual memory, and network adapters) together with communication protocols (such as TCP/IP and XTP) to support applications running on local and wide area networks. A taxonomy is presented that compares and evaluates four widely available transport systems in terms of their support for protocol processing. The systems covered in this paper include System V UNIX STREAMS, the BSD UNIX networking subsystem, the x-kernel, and the Conduit framework from the Choices operating system. This paper is intended to help researchers navigate through the transport system design space by describing alternative mechanisms for developing transport systems.
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Last modified 11:34:41 CDT 28 September 2006