The 100Mbps Ethernet bandwaggon gets under way in earnest this month when four companies, including a Hewlett-Packard co-AT&T Microelectronics team, present their ideas to the IEEE 802.3 committee. The team weighed in last week with the claim that it had developed a 100Mbps signalling system that will work over a voice grade unshielded twisted-pair cabling system. Brice Clark, strategic planning manager at Hewlett-Packard’s Sacramento networking division explained: we are saying that any technology that currently supports 10Base-T will support this [100 Mbps] – the same cable, the same connectors. Such a promise is vital to AT&T if it is to keep selling its popular Premises Distribution System structure cabling system. The announcement was welcomed by Grand Junction Networks Ltd, which proposed Fast Ethernet last month and is one of the other companies presenting ideas to the IEEE on November 9. It sounds like an unequivocally good thing… a tremendous service to the industry, said Grand Junction’s vice-president of marketing Jack Moses – assuming, he added that Hewlett-Packard and AT&T are planning to implement the Ethernet MAC specifications exactly. His support would be lost if the pair were to tinker with the Media Access Control, MAC, layer other than to multiply its speed by 10.

Grand Junction

Grand Junction’s welcome for what could be seen as a competing technology is explained by the fact that the Union City, California start-up has yet to nail its colours to any particular signalling system mast. We have some thoughts on signalling and will present them to the IEEE in due course, said Moses, but added that the company was only intending to outline generalities at the forthcoming meeting. By contrast, the last company to present to the meeting – Lan Media Corp, specialises in signalling. Ron Crane, who heads the small Santa Clara start-up, is one of the one of the original Ethernet team at Xerox Corp, and says it is more than feasible that Hewlett-Packard and AT&T have come up with a way of getting 100Mbps over voice grade. He refuses to be drawn on whether two majors apparently muscling in on his territory poses a serious threat to Lan Media, whose staff number ‘a handful’. It seems unlikely that the various parties will thrash out any form of compromise before the meeting on November 9 and therefore the IEEE will be faced with three conflicting proposals, Nonetheless there is feeling of compromise in the air. Our goals are extremely congruent with Grand Junction says Hewlett-Packard’s Clark. AT&T and Hewlett-Packard have been working together for the past nine months to a year on the 100Mbps signalling problem, and much of the work was done in the Hewlett-Packard labs in Bristol, Avon, Clark says. Which only leaves the question of why, if AT&T and Hewlett had the technology under development, didn’t they present it to the standards body working on the CDDI FDDI-over-copper standard. Clark claims that the – so far undescribed – signalling technology is fundamentally unsuitable for FDDI-type protocols, but will work quite happily with a speeded-up Ethernet. That sounds dubious says David Palmer-Stevens, European marketing manager with Cabletron Systems Inc, and firmly ensconced in the CDDI camp. Palmer-Stevens says that the signalling and MAC layers are completely independent and points out that as far as the lowest layer of the network is concerned, a bit is just a bit. Palmer-Stevens’s view is that the pair have decided they don’t want to use the MLT-3 encoding used by CDDI, and have decided instead to use their own technology to influence a standard that is still malleable. But, he warns, the window is getting very narrow – at InterOp this year, people were showing Asynchronous Transfer Mode.