Ethernet over phone lines catches on
- By Susan M. Menke
- Oct 22, 2004
All computers have Ethernet interfaces, 'so end-to-end Ethernet makes tremendous sense,' the EFM Alliance's Craig Easley says.
'Optical fiber is the future, but it's not everywhere' like copper telephone wiring, the president of the Ethernet in the First Mile Alliance told an audience of 100 small-agency CIOs last week in Washington.
The new IEEE 802.3ah standard for Ethernet in the first mile (EFM), ratified in July, will make it possible to extend TCP/IP far beyond local networks by attaching special modems to existing phone wiring.
'Ethernet is ubiquitous for LANs,' said Craig Easley, the metropolitan-area Ethernet director at Extreme Networks Inc. of Santa Clara, Calif. 'It just took a little work to extend it to WANs' with existing copper phone pairs or optical fiber.
The EFM WANs built so far are serving a few military bases, metropolitan areas, campuses and remote offices, but Easley said the technology could grow to fill in the last-mile gap between offices and homes and the telecommunications carriers' underused fiber core.
'There's a huge excess capacity' of core bandwidth amounting to terabits per second, he said, because of industry's fiber overexpansion before the economic recession.
Easley predicted EFM will become 'the next wave of broadband.' All computers have Ethernet interfaces, he said, 'so end-to-end Ethernet makes tremendous sense.' It eliminates the TCP/IP protocol translations and encapsulations' necessary for packet transport over frame relay, asynchronous transfer mode or Synchronous Optical Network. And, he said, 'It squeezes out complexity. It's all one technology from end to end.'
In a demonstration arranged by Brett Bobley, CIO of the National Endowment for the Humanities and co-chairman of the Small Agency CIO Council, Allied Telecom Group of Washington showed off EFM streaming live street traffic from a video camera at 13th and L Streets in the District.
Using Bobley's agency's EFM connection in the Old Post Office Building on Pennsylvania Avenue, Allied Telecom president Ken Williams controlled the camera tilt and zoom remotely. The EFM connection also fed a Web browser and a Cisco Systems Inc. voice over IP phone. To demonstrate that phone wiring has built-in redundancy, Williams snipped out one, two and then three of the four copper pairs without losing the video, Web connection or dial tone. When the EFM link was cut down to one pair, the streaming video became choppy but continued showing traffic clearly.
Williams recommended EFM not only for videoconferencing and surveillance but also for remote backup for disaster recovery.
Agencies in metropolitan areas with plentiful existing copper wiring can install EFM for data networking only. It does not interfere with existing phone systems or require changing users' Ethernet ports. But if the agencies choose to adopt VOIP as well, they have to install new Ethernet ports to prioritize different kinds of voice and data traffic. Multiple copper pairs can be aggregated into a so-called fat pipe to provide 2 Mbps to 40 Mbps of EFM bandwidth over distances up to a mile or so. Point-to-point EFM requires connecting the copper pairs at each end to a modem device, such as the MetaLight series from Actelis Networks Inc. of Fremont, Calif.