Full duplex Ethernet – operating in each direction at 10Mbps to give an aggregate 20Mbps – took a step forward this week when Cabletron Systems Inc, Compaq Computer Corp, IBM Corp, Kalpana Inc, National Semiconductor Corp, AT&T Co’s NCR Corp unit, Seeq Technology Inc and Texas Instruments Inc got together at NetWorld in Dallas to announce a consortium to develop interoperable products incorporating the Full Duplex Switched Ethernet access method. The consortium’s standard implements an auto-detect capability, eliminating the need for manual assignment and enabling full duplex adaptors and modules to interoperate on a standard Ethernet network. To accommodate existing products the proposal includes a backward compatibility feature. Kalpana, Sunnyvale pioneer of Ethernet switching, announced that it has successfully completed interoperability testing of its Full Duplex EtherSwitch products with IBM Corp’s EtherStreamer MC 32 Adaptor and Compaq Computer Corp’s NetFlex family of 32-bit Ethernet adaptors. Tests of switch-to-server connections between the Kalpana EtherSwitch and an IBM PS/2 Model 95 server or a Compaq ProLiant server demonstrated that full-duplex transmission more than doubles point-to-point Ethernet performance, the company claims – it says that at tests in Sunnyvale, throughput of the EtherSwitch-to-server links increased to 16.2Mbps from 8Mbps when full-duplex was enabled. In the test, half the participating stations were specified in a read operation and the other half in a write operation, which enabled the stations to take full advantage of the EtherSwitch-to-server connection’s bidirectional data path – an ideal situation. For the typical end user, the performance benefit of full duplex will be most visible in the increased speed of write-related operations to the server, Kalpana says. Full-duplex Ethernet technology has been proposed to the IEEE 802.3 committee and has received widespread support within the networking industry. Texas Instruments is taking the NetWorld platform to discuss the performance benefits of its new TMS380C24 chip, described as the first commercially available Ethernet communications processor to support full-duplex networking. National Semiconductor has already demonstrated its technology for full duplex Ethernet at InterOp West in San Francisco in August. And Interphase Inc of Dallas committed to develop full duplex systems for SBus servers, such as Sun Micro systems Inc’s Sparcserver.
