Ethernet speeds up to launch ATM challenge

A challenge to ATM has appeared on the horizon in the shape of a rearguard action from an older technology, Ethernet.

The latest incarnation of Ethernet will ship this autumn. Gigabit (Gbit) Ethernet will be 10 times faster than 100 Megabit (Mbit) Ethernet, the current fastest version of the networking standard.

Small networking player Plaintree has made a surprising claim that it will be the first company to ship Gbit Ethernet hardware, in June.

3Com is not promising Gbit technology until October. Bay will only say that it will ship its products sometime in the second half of the year.

But Plaintree's hardware will not actually run Gbit Ethernet. It will simply be ready to accept plug-in Gbit ports which the company expects to ship in October.

Marina Smith, senior analyst at research company Datapro, said: 'Plaintree hasn't got the profile of the others, so it's got to make more noise.

It's put a lot into into this, but if it is the first to ship, it'll only be by a few weeks.'

Plaintree claims that 90% of LANs already use standard and 100Mbit Ethernet, and that the Gbit version will allow Ethernet to reach out onto the backbone.

That would eliminate protocol changes at the interface between the LAN and the backbone. It would also be at the expense of ATM, which is most used on the backbone.

Jeff Pinkham, director at Plaintree UK, said: 'Until now the accepted way to connect two buildings has been to use ATM. But ATM is complex and costly, and it doesn't bring anything to the party.'

Datapro's Smith said the advantages of using the Ethernet 'we know and love' to cover an entire network are evenly balanced by the superior technical qualities of the admittedly 'complex' ATM.

'People get religious about which way to go. Certainly, if you're planning to put in video conferencing you'll need to go with ATM, but apart from that there are good arguments for either choice,' she said.

A standard for Gbit Ethernet has not yet been ratified. Smith warned that the eventual true data capacity of Gbit Ethernet will depend on what is ratified, and could lie anywhere between 0.5Gbit and 1.5Gbit for a full duplex channel.