I have read that the speeds you can obtain with a DSL connection vary depending on how far you are from the CO (central office). For instance, if customer A is 12,000 ft from the CO and customer B is 2,000 ft from the CO, customer B would get a higher bandwidth than customer A. Is this true? If so, is degradation the cause?
Tek-Tips is the largest IT community on the Internet today!
Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!
-
Congratulations Mike Lewis on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!
DSL and distance from the CO
- Thread starter mondy
- Start date
When the line is provisioned your contracted line speeds are set. If they promised you xxx upload / xxxx download, you should receive it no matter the distance from the CO.
If your distance is far, you may not be able to sign for the highest bandwidth offered by the ISP.
Someone closer to the CO will receive their contracted bandwidth, and hopefully no less. The same applies for a customer farther away from the CO.
If your distance is far, you may not be able to sign for the highest bandwidth offered by the ISP.
Someone closer to the CO will receive their contracted bandwidth, and hopefully no less. The same applies for a customer farther away from the CO.
- Thread starter
- #3
distance from the co matters for speed because of energy. DSL is 4000 Khz and above allowing digital data to flow fast. the downsize is the farther from the dslam ( a multiplexer located in the co that generates your dsl piple]. therefore if you live close = fast speed farther out = slower speeds.
so watch out for isp's providing service when you KNOW how far you really are from the co.
so watch out for isp's providing service when you KNOW how far you really are from the co.
- Thread starter
- #5
It does make sense. If they contract with you for an upload of xxx and a download of xxx, they have already checked your distance from the CO and feel confident that they can provide that level of service.
If you contract for 1.5 down, and receive 900 kbs, they have to resolve the issue for you.
If you contract for 1.5 down and are 200 feet from the CO, you will get 1.5 down. The line is provisioned for a certain upload and download bandwidth. I have seen cable systems were their offers are vague as to the speed, but your DSL ISP should be quite definite as to the speed you are contracting for.
If you contract for 1.5 down, and receive 900 kbs, they have to resolve the issue for you.
If you contract for 1.5 down and are 200 feet from the CO, you will get 1.5 down. The line is provisioned for a certain upload and download bandwidth. I have seen cable systems were their offers are vague as to the speed, but your DSL ISP should be quite definite as to the speed you are contracting for.
Where I live, SBC offers two basic levels of service: 768/128 and 1.5/512 ADSL connections. Before a customer signs up, they are specifically told that speeds may vary depending on the distance from the CO. Obviously, the further away, the smaller the maximum bandwidth. However, just because you're closer, doesn't necessarily mean you're going to get better speeds. First of all, they'll cap you. Secondly, they don't offer service outside the tested ranges.
I don't currently subscribe to SBC, but when I did a while back, I was almost 16,000ft away from the nearest CO (18,000 being the maximum). Any distance within this range should receive 768/128 no problem, assuming other factors like your house's wiring or interference from other devices aren't at play. The business class service (1.5/512) was only available to locations less than 12,000ft away.
If you're not getting the speeds you signed up for, most DSL providers have a provision in their contracts to allow you to cancel early without penalty. However, I think it would be incorrect to say that the company "has to" resolve it for you. They can try, but in the end, it could just mean a cancellation in your contract.
~cdogg
[tab]"The secret to creativity is knowing how to hide your sources"
[tab][tab]- A. Einstein
I don't currently subscribe to SBC, but when I did a while back, I was almost 16,000ft away from the nearest CO (18,000 being the maximum). Any distance within this range should receive 768/128 no problem, assuming other factors like your house's wiring or interference from other devices aren't at play. The business class service (1.5/512) was only available to locations less than 12,000ft away.
If you're not getting the speeds you signed up for, most DSL providers have a provision in their contracts to allow you to cancel early without penalty. However, I think it would be incorrect to say that the company "has to" resolve it for you. They can try, but in the end, it could just mean a cancellation in your contract.
~cdogg
[tab]"The secret to creativity is knowing how to hide your sources"
[tab][tab]- A. Einstein
- Thread starter
- #8
So.....
If my DSL provider tells me that I WILL get 768/128 for $$$
or I WILL get 1.5/128 for $$$, then they have already tested the lines and are certain that I can reach that amount of bandwidth?
and...
If my DSL provider simply tells me that my bandwidth will range from 384-1.5 and I will pay $$$ no matter where I fall into that range - they have NOT tested my lines and will not guarantee a consistent 768 or 1 meg connection?
Verizon does not specify what my speed will be. According to their website it will range between 384 and 1.5 Which DSL providers specify the bandwidth a customer will achieve?
If my DSL provider tells me that I WILL get 768/128 for $$$
or I WILL get 1.5/128 for $$$, then they have already tested the lines and are certain that I can reach that amount of bandwidth?
and...
If my DSL provider simply tells me that my bandwidth will range from 384-1.5 and I will pay $$$ no matter where I fall into that range - they have NOT tested my lines and will not guarantee a consistent 768 or 1 meg connection?
Verizon does not specify what my speed will be. According to their website it will range between 384 and 1.5 Which DSL providers specify the bandwidth a customer will achieve?
Also remember that companies like Earthlink and Verizon are usually leasing the lines from SBC, since SBC physically owns a vast portion of the telephone lines and operations in the Eastern US. If your ISP is leasing, then that might explain why you are given a range instead of a guarantee. They are simply providing an estimate instead of a tested result.
Nevertheless, this should always be part of the conversation when speaking to a sales rep before agreeing to any contracts.
~cdogg
[tab]"The secret to creativity is knowing how to hide your sources"
[tab][tab]- A. Einstein
Nevertheless, this should always be part of the conversation when speaking to a sales rep before agreeing to any contracts.
~cdogg
[tab]"The secret to creativity is knowing how to hide your sources"
[tab][tab]- A. Einstein
- Thread starter
- #11
It all depends on the ISP. Now that you've pointed out it's Verizon, distance probably does matter. With a company like SBC, it doesn't because they'll cap the speed to ensure you're not getting speeds higher than your plan. I'm not sure about companies like Verizon or Earthlink, though I am sure it's stated within their contract or policy.
The point is to find out from them directly. Not every ISP operates the same way. In technical terms, being closer does allow for higher speeds. But due to "capping", you may never see it.
~cdogg
[tab]"The secret to creativity is knowing how to hide your sources"
[tab][tab]- A. Einstein
The point is to find out from them directly. Not every ISP operates the same way. In technical terms, being closer does allow for higher speeds. But due to "capping", you may never see it.
~cdogg
[tab]"The secret to creativity is knowing how to hide your sources"
[tab][tab]- A. Einstein
mondy,
The clear answer is that the line is provisioned at a set speed. This is what you contract for. It is easier for the DSL modem to synch reliably the closer to the CO, but the DSLAM will be set to the provisioned speed no matter what your distance. If your distance exceeds what reliably can be done, the ISP will not provide you a contract for those speeds.
Your distance is only relevant to what the ISP can offer you in terms of a bandwidth plan. A guy much closer to the CO would be in a better position than one farther away to obtain higher bandwidths, but the provisioning of the DSLAM will restrict him to just what his contract says.
The clear answer is that the line is provisioned at a set speed. This is what you contract for. It is easier for the DSL modem to synch reliably the closer to the CO, but the DSLAM will be set to the provisioned speed no matter what your distance. If your distance exceeds what reliably can be done, the ISP will not provide you a contract for those speeds.
Your distance is only relevant to what the ISP can offer you in terms of a bandwidth plan. A guy much closer to the CO would be in a better position than one farther away to obtain higher bandwidths, but the provisioning of the DSLAM will restrict him to just what his contract says.
- Thread starter
- #14
OK. I got it. I think I was puzzled because I never knew that DSL providers were able to provision the bandwidth like you can with cable modem service. I thought that was an advantage for cable. Have DSL providers always been able to provision the bandwidth or is this a recent development?
Provisioning the line has always been a prerequisite to receiving service from a DSL ISP. Your line is basically given an ID number back at the CO, which can then be used to establish a connection through the ISP's server. During the initial phase, testing is done by the ISP through a series of diagnostic tests. Normally, one or more tests will report an error if there's a possibility that your connection will have problems.
Back to the bandwidth debate for sec...
The important thing to realize is that most contracts from the ISP rarely state a guarantee for any particular speed. It is not uncommon for many people to receive 60-70% of the rated speed, not in violation of the contract. I have verified this with several ISP's (AOL, SBC, Roadrunner). The same goes for Cable ISP's. With cable, the more people connected to one node hampers the connection at peak times throughout the day. This is why both DSL and Cable ISP's rarely state a guarantee.
Back to the bandwidth debate for sec...
The important thing to realize is that most contracts from the ISP rarely state a guarantee for any particular speed. It is not uncommon for many people to receive 60-70% of the rated speed, not in violation of the contract. I have verified this with several ISP's (AOL, SBC, Roadrunner). The same goes for Cable ISP's. With cable, the more people connected to one node hampers the connection at peak times throughout the day. This is why both DSL and Cable ISP's rarely state a guarantee.
It has not been my experience that DSL providers will not gaurantee the contracted speed. Cable cannot offer anything other than a range, but for ADSL you should be offered firmly a contracted speed without any reservation after qualifying your line.
If not, choose a different ISP.
If not, choose a different ISP.
- Thread starter
- #17
I know that most cable ISPs use a tiered structure. They offer say 3 pkgs... 384, 768, 1.5+ etc. Each with a different price. They tell you that this is a "maximum bandwidth". They don't mention that you will most likely get about 70-80% of that unless you specifically ask or have a slow speed issue.
A friend of mine told me of his story with Earthlink DSL on SBC lines. He was getting 1.7 Mbps for about 2 weeks and then it dropped down to the 500 kbps range. He called and they said that is normal for your block. He tried to cancel and they would not release him of his contract without paying the penalty. Ouch! He did say later that the speed went up to around 800 kbps after a couple weeks.
A friend of mine told me of his story with Earthlink DSL on SBC lines. He was getting 1.7 Mbps for about 2 weeks and then it dropped down to the 500 kbps range. He called and they said that is normal for your block. He tried to cancel and they would not release him of his contract without paying the penalty. Ouch! He did say later that the speed went up to around 800 kbps after a couple weeks.
- Status
Similar threads
- Locked
- Question
- Locked
- Question
