Copper Mountain aims for efficient ATM-based DSL nets

DSL equipment maker Copper Mountain Networks has unveiled a concentrator designed to increase the efficiency of ATM-based DSL...

DSL equipment maker Copper Mountain Networks has unveiled a concentrator designed to increase the efficiency of ATM-based DSL networks.

Called the VantEdge 3000 Broadband Services Concentrator, the IP-based box provides functions such as policy-based class of service, subscriber aggregation and traffic shaping for ATM DSL nets. Copper Mountain said the box should be generally available by April 2002.

"This allows us to get into the ILEC marketplace and into the international carriers which have deployed ATM," said Bryan Long, vice-president of marketing at Copper Mountain. "We had to be realistic. We knew we weren't going to go in and sell these guys new IP-based DSLAMs when they'd already invested in ATM."

Currently DSL providers with ATM networks use ATM switches to aggregate subscriber traffic from their DSLAMs at Layer 2, Long says. Subscriber management systems from firms like Redback Networks provide Layer 3 aggregation.

This method becomes very inefficient as the DSL network scales, Long says, because aggregating the traffic flows at Layer 2 means a virtual circuit must be kept open for each subscriber all the way back to a service provider's point of presence in a metro area.

By aggregating DSL traffic onto a VantEdge 3000 at each central office, service providers eliminate the need to maintain virtual circuits between the central offices and their point of presence. Layer 2 virtual circuits will still handle quality of service between the subscriber and central office, but between the central office and the point of presence, quality of service would be handled at Layer 3 through class of service.

The VantEdge should also allow service providers to reduce the number of subscriber management systems they require, Long says, because the subscriber management boxes won't have to provide any Layer 3 aggregation. They can be used solely for subscriber management.

Since the VantEdge is IP-based, it's a good fit for carriers who anticipate moving to an IP-based network down the road, Long adds.

The VantEdge is designed for central office deployment. The 20-slot box is 24.5 inches high, 23 inches wide and 12 inches deep and can support up to 912 ports of asymmetric DSL or G. SHDSL per chassis. WAN interface options include T-1, DS-3, OC-3, OC-12 and Fast or Gigabit Ethernet.

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