Goals| Partners: |
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| Contact Persons: | Ferdinand Hommes, Ralph Niederberger |
GoalsThe installation, configuration and management of the ATM components and net structure are necessary preconditions for the successful support of applications in the Gigabit Testbed. Survey of the net and its components, attendant measurements and also special performance experiments will help to analyse the behaviour of the net and the applied protocols, to recognize strength and weakness of the ATM Gigabit technique and to judge the future development.
Installation and
ConfigurationIn August 1997 a 622 Mbps SDH/ATM connection between GMD and FZJ was installed by o.tel.o . One year later in August 1998 it was upgraded for tests to 2.4 Gbps. It has been one of the first ATM connections in Europe using this bandwidth . From the beginning the connection has been supervised by the HP-Openview management tool in GMD. The connection has been stable without unpredicted interruptions. The following figure describes the current configuration of the Gigabit Testbed West.
The workstations in the Testbed communicate by Classical IP and/or LAN Emulation. Joint Classical IP or LAN Emulation nets are defined for different purposes to connect the different sites and partners in applications. Permanent Virtual Circuits are configured for a native ATM Video Conference System from Siemens and also for the connection of 8 IBM SP2 nodes with the CRAY T3E.
StatusDelay and performance tests have been executed. The results of the delay tests are in accordance with the theoretically calculated values. The performance tests showed that multiprocessor workstations are able to take full advantage of the available bandwidth. Further experiments showed that numerous parameters, as for example buffer size, message size, transport protocol, traffic shaping, traffic contracts, component interoperability, influence heavily the performance results.
SGI/CRAY and IBM currently do not support ATM interfaces with transmission speed higher than 155 Mbps for the CRAY/T3E and the IBM/SP2. Therefore in the meantime other alternatives have been setup.
Using some sort of preprocessors connected to the mainframes with HiPPI technology and communicating via ATM 622 Mbps interfaces seems to be a practical solution particularly since CRAY also favourises this technique for their systems with Gigaring technology. The following figure describes the configuration that has been implemented and is currently tested.
Publications
