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| What is SDSL |
| SDSL (ISDN digital subscriber line) is the longest ranging of the new DSL access technologies used to provide high speed, always on, network services over existing copper wire. |
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| What are the key benefits to SDSL |
| SDSL has several deployment advantages over other DSL technologies such as ADSL and SDSL, and is better suited as a high quality, low cost, alternative to analog dial services: |
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| What does it take to order SDSL? |
| You need to be within 25,000 feet range of a key phone company installation in Ames, Ankeny or the Des Moines metropolitan area |
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| What are the factors when ordering SDSL? |
| Beyond the distance factor you of course need to have knowledge of how the phone company wiring comes up to your building. Also you may request a site survey at modest or even no cost in certain circumstances and do ask us about this option. |
| SDSL |
SDSL uses proven loop technology (based on existing ISDN circuits) and can operate up to 18,000 feet, or longer with repeaters. This means service providers can offer a DSL service to all customers, irrespective of their distance from the central office. Other DSL technologies cannot operate through repeaters and very quickly lose their speed advantages over long distances.
SDSL can even operate through a digital loop carrier (DLC) based circuit, unlike other DSL technologies. It is estimated that up to 50% of customers are served through DLCs today in some locations.
SDSL operates at significantly higher speeds than analog modems, and provides an always-on network connection.
SDSL offers a fully symmetric service.
No loop qualification is required, significantly reducing the deployment cost of service.
Although based on the ISDN transceiver technology, SDSL does not operate over the ISDN voice switch; it is terminated at the DLAM (digital subscriber line access multiplexer). This offloads the voice network of the high-utilization data calls and ensures the service provider can make more efficient use of the existing networks.
SDSL uses ISDN-based copper circuits, existing 2B1Q signaling, but does not used the D-channel signaling for circuit establishment and monitoring. Unlike ISDN, SDSL has no call set-up sequence and will be positioned by the service providers as a flat rate service, rather than usage based. |
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