Eric C. Cooper

Designing a practical ATM LAN

The adaptor cards and driver software for workstations and local asynchronous transfer mode (ATM) switches and switch control software used in an ATM local area network (LAN) system are discussed. It is shown that the ATM hardware and software components together provide services that are essential for ATM to be considered a realistic alternative to current shared-media LANs. These services include: completely transparent support for the TCP/IP protocol suite, an application programming interface for full access to the underlying ATM capabilities, support for AAL5, AAL3/4, and the null AAL, both connection-oriented and connectionless service, dynamic connection establishment or switched virtual circuits, resource reservation of guaranteed bandwidth and quality of service, full-bandwidth multicast and broadcast, virtual path and channel routing among multiple switches, automatic configuration and failure recovery, dynamic address assignment and internetwork address resolution, and network management via the simple network management protocol (SNMP).<<ETX>>

Protocol implementation on the Nectar Communication Processor

We have built a high-speed local-area network called Nectar that uses programmable communication processors as host interfaces. In contrast to most protocol engines, our communication processors have a flexible runtime system that supports multiple transport protocols as well as application-specific activities. In particular, we have implemented the TCP/IP protocol suite and Nectar-specific communication protocols on the communication processor. The Nectar network currently has 25 hosts and has been in use for over a year. The flexibility of our communication processor design does not compromise its performance. The latency of a remote procedure call between application tasks executing on two Nectar hosts is less than 500 μsec. The same tasks can obtain a throughput of 28 Mbit/sec using either TCP/IP or Nectar-specific transport protocols. This throughput is limited by the VME bus that connects a host and its communication processor. Application tasks executing on two communication processors can obtain 90 Mbit/sec of the possible 100 Mbit/sec physical bandwidth using Nectar-specific transport protocols.

Host interface design for ATM LANs

ATM (asynchronous transfer mode) is an international telecommunications standard designed for broadband integrated services; it is also well-suited for use within local-area networks. ATM LANs can provide the networking support needed for multimedia communication at rates of 100 Mbits/sec and higher. The authors first analyze the protocol processing required to handle ATM communication. Based on this analysis, they then discuss the architectural issues in the design of host interfaces for ATM local-area networks. In particular, they conclude that a simple host interface, which leaves most of the ATM protocol processing to be done by the host computer, supports good performance for data communication (around 100 Mbits/sec). However, to support real-time video and audio communication, the ATM interface should include an embedded processor.<<ETX>>

Network-based multicomputers: an emerging parallel architecture

No abstract available

Programming language support for multicast communication in distributed systems

A spectrum of abstractions for multicast communications is introduced in increasing order of both desirability and semantic level: functional mapping, iterators, and streams. Examples of distributed algorithms from the literature are used to illustrate the expressive power of each mechanism. Streams, in particular, provide first-class status for multicast communication in progress and can be implemented efficiently in typical multicast communication architectures. Related work and the criteria for multicast support are discussed. The layers of a typical distributed system that are relevant to language support for multicast communication are discussed.<<ETX>>

Programming language support for replication in fault-tolerant distributed systems

Replication is the primary means of achieving high availability in fault-tolerant distributed systems. Multicast or group communication is a useful tool for expressing replicated algorithms and constructing highly available systems. But programming language support for replication and group communication is uncommon.This position paper discusses three language constructs---functional mapping, iterators, and streams---that can be used for replicated communication at the programming language level. These mechanisms are evaluated using a set of essential and desirable properties.