Offering ATM-Based Leased Line Services over DSL

When carriers use TDM networks for n x 64 kbps leased line service, they invest in expensive multiplexing and termination equipment at the central office and customer premises, respectively. They also waste bandwidth that is reserved for each customer.

The proliferation of ATM transport and backbone networks and the growing deployment of high speed ADSL for Internet access offer carriers the opportunity to leverage their ATM infrastructure to deliver integrated, leased line services. With so many ATM-based DSLAMs out in the field, carriers can sell additional services over the lower speed DSL loops.

To provide the ATM leased line service, the carrier installs RAD's LA-110 or LA-140 DSL integrated access device (IAD) at the customer premises. These are cheaper than TDM devices, and can be connected to the DSLAM over ADSL, SHDSL, SDSL or E1. The IADs integrate voice and data through a G.703/G.704, X.21, V.35 or V.36 user interface. They convert the traffic into ATM packets using AAL1 for circuit emulation (AAL1-CES) and send them over xDSL on an ATM PVC with ATM Quality of Service (e.g., CBR). Enterprises requiring more bandwidth at headquarters can build a network combining lower speed DSL at branch offices and direct ATM service at the main office.

Next generation cellular networks also require ATM network capabilities. RAD's IADs can transport cellular traffic over the DSL network to the ATM backbone. Carriers with deployed DSL networks will be able to increase revenues by selling transport services to cellular operators.