Rhythms NetConnections is pouncing on new technology that raises digital subscriber line from a replacement technology for T-1 circuits to a replacement for fractional T-3 services.
Based on DSL inverse multiplexing (IMUX) hardware and software from Copper Mountain, Rhythms this fall will introduce access services that range up to 12M bit/sec, the equivalent of eight T-1 circuits.
Rhythms' announcement follows news this week that Northpoint Communications will use the same Copper Mountain IMUX gear to support high-bandwidth services before year-end.
The price of an inverse multiplexed service will be less than the cost of an equivalent number of individual DSL circuits, according to Jim Greenberg, Rhythms chief network officer. For example, a 384K bit/sec symmetric DSL (SDSL) line costs $150 per month, but two inverse multiplexed lines delivering 768K bit/sec would cost less than $300. Exact prices have not been set, he says.
Like regular DSL, the bandwidth the customer can get depends on how long the wire is between the customer and the carrier network. The longer the distance, the lower the bandwidth.
Copper Mountain's IMUX equipment logically bonds together individual DSL lines into a single larger pipe. The Copper Mountain devices support two flavors of DSL: SDSL and ISDN-based DSL (IDSL).
By bonding up to eight SDSL lines, Copper Mountain equipment can deliver what appears to be a single 12M bit/sec pipe, bandwidth otherwise available only by installing a full 45M bit/sec T-3 circuit and using just part of it or by inverse multiplexing more expensive T-1 lines.
A free software upgrade enables Copper Mountain's Copper Edge DSL concentrator to meld up to eight customer lines as they enter a service provider network. Copper Mountain plans to introduce two pieces of customer premise equipment that also support inverse multiplexing, but that equipment bonds only two lines.
However, next year Copper Mountain and its partners plan to build compatible customer devices that bond more than two lines, Copper Mountain says. The company would not say which partners.
The Copper Mountain SDSL box is called CopperRocket 202 Symmetric DSL IMUX DSU and bonds two lines at up to 1.5M bit/sec each. It costs $995.
Copper Mountain IDSL gear is the CopperRocket 212 IDSL IMUX and costs $895.
IDSL is the only DSL technology that can be supported by remote carrier access stations known as digital loop carriers (DLC). Inverse multiplexing IDSL enables customers served by DLCs to get more than the 144K bit/sec maximum bandwidth of a single IDSL line.
RELATED LINKS
