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Note: This section is out of date and no longer maintained.
It is retained for the value of any residual information contained in it.

technical hurdles

Otherwise known as the No DSL? page. The Telcordia website has (had) a section about Sapphyre loop qualification problems what's the problem with ADSL deployment .. The number one most likely culprit if you cannot currently get DSL, is a DLC, (sometimes known as an SLC). Click DLC to read what this is, the explanation of the DLC issue will appear below this section. Other problems include old copper circuits, wire too thin, load coils, bridge taps, DLCs (SLCs), bad connectors, mains hum leakage. These can all potentially ruin the chance that a local loop can provide DSL service, or rule out some of the faster speeds available.
Our experience with the Can I get DSL function show that currently, in the US, something like 50% of people cannot current get DSL, either because they are too far from the CO, or their CO is not DSL enabled yet, or they are behind some telephone architecture that is not DSL compatible yet.
If you cannot initially get DSL, all is not completely lost. You may find out there is an alternative phone company CO (wire center) that you can receive phone service from, nearer your house or business premise. This is more likely in highly built-up areas with many competing communication companies.
In the case of a DLC getting in your way, your Telco could also have plans to retro-fit it with new cards that allow DSL, in fact, up-rating DLCs is the solution of choice for most telcos. For an interesting document on the pros and cons of ADSL vs Fibre vs DLCs, check out Extending ADSL services to remote DLC locations tutorial. If simple distance is the problem, you might be able to get IDSL, or RADSL, which stretch a little further than standard ADSL.
Bridge taps could be removed in your area, or with rollout experience, some DSL CLECs may extend the maximum foot limit they currently will entertain.

bridge taps

A bridge tap is a technique for telephone installs that taps you into a line that runs past your house, rather than terminating at your house. The line doesn't go to anyone elses premise, it just ends, maybe a mile up the road. This is useful should people move out, demolish a house or whatever, the phone company can move the tap up or down to service whomever it wishes. Unfortunately, you have a mile of unterminated phone line running up the road ready to pick up any interference, like a huge TV antenna. Because it isn't terminated, signals bounce up and down the line and can reinforce or cancel the signals your equipment is trying to send to your ISP. This can and does play havoc with 56k modems. Telcos will not pay much attention to customer complaints about bridge taps since they do not guarantee data beyond 2400 baud, however, a DSL line is supposed to be a new clean install, and so you should not get any bridge tap surprises.. but if your provider mentions this, now you know what they are talking about.

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