| dsl download upload question Im new to the telco industry so please bear with me. In dsl are the tip and ring sides of the twisted pair, considered download and upload. We have a customer that we send out 1.5 meg down, and 512kbps up. We just took a look at her readings from the c.o. and noticed the upload is only at 320, and everytime we reset her connection thats as high as it will train at. Would that indicate that one half of the pair is bad or does upload and download transmit one way on one side and transmit the other way on the other wire. Thanks Kevin |
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 PashuneCaps stifle innovationPremium
join:2006-04-14
Gautier, MS
 ·CableOne
| From what I understand both upload and download frequencies are equally transmitted on both the wires. In other words the modem would still attempt to possibly sync even if you cut one of the wires.
A low upload sync might point to a bad filter somewhere, line interference, bad modem and/or a bad pair. There are a ton of variables involved unfortunately.
I don't work in the telco business though.. this is just based on my research alone.
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CableOne 50/2 |
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 Hayward K A R - 1 2 0 CPremium
join:2000-07-13
Key West, FL
kudos:1
2 edits | reply to hemoon4
And actually if any noise issues etc UL being the lower frequency fairs best.
If DL is the 1.5 is the speed its meant to be then sounds like a provisioning error.
And no Tip and Ring have nothing to do with it all the same RF sub-carrier riding on DC POTS line or alone (dry)... but again the DL the higher frequency and bigger bandwidth most prone to error... very rare UL is the only issue.
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 tschmidtPremium,MVM
join:2000-11-12
Milford, NH
kudos:8
 ·G4 Communications
·Fairpoint Commun..
 ·Hollis Hosting
| reply to hemoon4
DSL spectrum |
DSL uses higher frequencies to send data to customer (downstream) and lower frequencies to send data to the Internet (upstream). The extremely low frequencies are not used by DSL so the line is able to continue to support ordinary phone service (POTS).
It may be that the line has become unbalanced. The best way to determine line condition is to run a mechanized loop test (MLT) to generate a report on the condition of the physical circuit.
If all looks good with the MLT there may be a problem with high frequency noise, perhaps a problem with some of the equipment at the customer site or a old style carbon protector that has become noisy. Assuming this is a self-install customer make sure they are using inline filters at all non-DSL devices and that they have installed the filters in the correct direction.
Because upstream uses lower frequencies it is usually not a problem, but there is a tremendous variation in the field.
Good luck troubleshooting.
/tom
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tschmidtPremium,MVM
join:2000-11-12
Milford, NH
kudos:8 Reviews:
·G4 Communications
·Fairpoint Commun..
·Hollis Hosting
| reply to hemoon4
Since you work for an ISP may want to learn more about the telephone network and DSL.
Telephony basics:
»www.cisco.com/networkers/nw99_pres/401.pdf
»www.hermonlabs.com/Products/inne···view.pdf
Nice DSL overview from Allied Telesis
»www.alliedtelesis.com/media/pdf/dsl_wp.pdf
/tom |
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