Bringing DSL to the remote cabinet

Occam Networks last week unveiled a line of broadbandloop carriers designed to ease the rollout of DSL to remote terminals.

The BLCs combine the functions of a DSL access multiplexer (DSLAM), a media gateway and a digital-loop carrier (DLC) in one box. They support plain old telephone service and asymmetric DSL (ADSL) on each port and can be integrated with voice softswitches via media gateway functions.

Occam's two initial BLCs are the BLC-1100, which has a one-rack-unit profile, and the BLC-2200, which has a five-rack unit profile. The BLC-1100 supports ADSL, while the BLC-2200 can support ADSL, single-pair high-bit-rate DSL or Gigabit Ethernet.

Although the BLCs are designed to fit into remote cabinets, Occam says they can also be deployed in central offices. But most telecom providers service between 20% and 40% of their subscriber base from remote terminals, says Claudia Bacco, an analyst with research firm TeleChoice.

"Right now there's a market the service providers can't address with DSL and that's the [digital-loop carrier] market," Bacco says.

To serve DSL to these subscribers, providers had to install a DSLAM and cabinet near each remote terminal and cross-connect the DLC and DSLAM, or rely on proprietary line card technology in the DLCs. The line card technology has not been popular with providers, Bacco says, because it often doesn't work well with other DSL equipment the providers might have installed.

Two small incumbent local exchange carriers are putting the BLCs through their paces.

Rural Telephone, in Lenora, Kan., has two BLC-1100s in service - one in a remote terminal and the other in a central office. Shane Broyles, the service provider's research and development coordinator, says the company has been serving its DLC clients through ISDN-based DSL, using ISDN line cards.

"But we figured the day was coming when 128K bit/sec wasn't going to work for people," he says.

The BLC-1100 is slated for general availability in the third quarter, while the BLC-2200 will be available in the first quarter of 2002. Pricing has not been finalized on the BLCs, but Occam expects per-port pricing to be between $450 and $500.

» posted by ITworld staff

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