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The 4 x 8-way Switch

The 4 x 8-way switch module consists of 4 RCube switches with all their links brought to the front panel for connecting to other switch modules or network interface cards using coaxial cables. The block digram of the switch module is shown in figure 6. A T8 microcontroller is used to configure and monitor the RCube switches. IEEE 1355 DS-Links are used to to control the module. Alternatively RS232 can be used. Two connections are provided, which allows a daisy-chain or a star topology to be used for the control of several such modules.

 
Figure 6: Block diagram of the 4 x 8-way switch  

The module is built in 19'' mechanics. A prototype of this module has been manufactured and tests have been carried out using a 66 MHz clock for the RCubes. Using the HS-Link evaluation board presented above as a data source, a continuous data stream has been transmitted bidirectionally through the four RCubes. The measured per link bidirectional throughput of 62 Mbyte/s corresponds to the expected value for the Bullit devices on the evaluation board running at 64 MHz.

A total of four of these modules will be built for the full 64-node testbed. They are required for the terminal stage switches in multistage networks and can also be used to construct grid and hypercube topologies.

The Network Description Language (NDL) has been extended to incorporate the RCube device. The low level software package, originally developed for use in configuring and monitoring the Macrame DS-Link network uses these extensions to allow for the control of heterogeneous networks of HS and DS-Links.



Stefan Haas
Tue Mar 31 11:54:08 MET DST 1998