Why is the upload capacity slow ?

I don't understand why most ADSL packages offer the same UPLOAD speed,
and varying DOWNLOAD speeds. Is there some sort of technical contraint
that explains the fact 256k download is the norm ?

Cheers

--
Darren

<(E-Mail Removed)> wrote in message
news:dc0129$6q6$(E-Mail Removed)...
>I don't understand why most ADSL packages offer the same UPLOAD speed,
> and varying DOWNLOAD speeds. Is there some sort of technical contraint
> that explains the fact 256k download is the norm ?

This is a question that's been puzzling me as well. You'd expect that upload
speed would increase in the same proportion as the download speed:

512K Down / 256K Up
1M D / 512K U
2M D / 1M U

Evidently each doubling of the download speed doesn't involve allocating
exactly twice as much bandwidth[*] to the ADSL signal, partitioned as 66%
down and 33% up.
[*] In the true electronic engineering sense of the word "bandwidth" - ie
not the broadband meaning of "total quantity of data downloaded in a given
time".

On Sun, 24 Jul 2005 13:45:02 +0100,it is alleged that "Martin
Underwood" <(E-Mail Removed)> spake thusly in uk.telecom.broadband:

><(E-Mail Removed)> wrote in message
>news:dc0129$6q6$(E-Mail Removed)...
>>I don't understand why most ADSL packages offer the same UPLOAD speed,
>> and varying DOWNLOAD speeds. Is there some sort of technical contraint
>> that explains the fact 256k download is the norm ?
>
>This is a question that's been puzzling me as well. You'd expect that upload
>speed would increase in the same proportion as the download speed:
>
>512K Down / 256K Up
>1M D / 512K U
>2M D / 1M U
>
>Evidently each doubling of the download speed doesn't involve allocating
>exactly twice as much bandwidth[*] to the ADSL signal, partitioned as 66%
>down and 33% up.
>
>[*] In the true electronic engineering sense of the word "bandwidth" - ie
>not the broadband meaning of "total quantity of data downloaded in a given
>time".

Cynicism mode: On
Because they want you to pay through the nose for expensive SDSL or
equivalent business service to get high upload speeds.

--
This .signature has been hijacked by the Shellfish Liberation Army.
Please remain clam.

On Sun, 24 Jul 2005 14:15:10 +0000 (UTC),
(E-Mail Removed)lid wrote:

>I wouldn't be surprised ! How can you tell if your exchange is SDSL
>capable ? (Or whatever the correct terminology is)

http://www.samknows.com/broadband/

--
Cheers,

Guy

** Stress - the condition brought about by having to
** resist the temptation to beat the living daylights
** out of someone who richly deserves it.

Chip <(E-Mail Removed)> wrote:

> Cynicism mode: On
> Because they want you to pay through the nose for expensive SDSL or
> equivalent business service to get high upload speeds.

I wouldn't be surprised ! How can you tell if your exchange is SDSL
capable ? (Or whatever the correct terminology is)

--
Darren

(E-Mail Removed)lid wrote:
>How can you tell if your exchange is SDSL
> capable ?

http://www.samknows.com/broadband/checker2.php

In message <42e38e97$0$2775$(E-Mail Removed)>, Martin
Underwood <(E-Mail Removed)> writes
><(E-Mail Removed)> wrote in message
>news:dc0129$6q6$(E-Mail Removed)...
>>I don't understand why most ADSL packages offer the same UPLOAD speed,
>> and varying DOWNLOAD speeds. Is there some sort of technical contraint
>> that explains the fact 256k download is the norm ?
>
>This is a question that's been puzzling me as well. You'd expect that upload
>speed would increase in the same proportion as the download speed:
>
>512K Down / 256K Up
>1M D / 512K U
>2M D / 1M U
>
>Evidently each doubling of the download speed doesn't involve allocating
>exactly twice as much bandwidth[*] to the ADSL signal, partitioned as 66%
>down and 33% up.
>
>[*] In the true electronic engineering sense of the word "bandwidth" - ie
>not the broadband meaning of "total quantity of data downloaded in a given
>time".
>
>
>
>
Simple really. The pair of wires linking you to the exchange carries
signals in both directions. The available frequency spectrum is (in
general terms) split into three chunks
Low < 4Khz used for Voice
Med roughly 60-600Khz Upstream
600 - The limit of your line Downstream

As the frequency limit of your line increases all the additional
frequency spectrum is all allocated to the Downstream segment.

For excruciating detail beyond this Google ADSL Frequency spectrum
--
Peter R Cook

On Sun, 24 Jul 2005 15:24:31 +0100, Davew
<daviey.walker*spam*virgin.net> wrote:

>(E-Mail Removed) wrote:
>>How can you tell if your exchange is SDSL
>> capable ?
>
>http://www.samknows.com/broadband/checker2.php


Seems I have a wide choice in my area!

BT Wholesale ADSL
BT Wholesale SDSL
ntl:home cable
Bulldog LLU ADSL and SDSL
Easynet LLU ADSL and SDSL
HomeChoice LLU ADSL/TV




--
www.senaction.com

<(E-Mail Removed)> wrote in message
news:dc0129$6q6$(E-Mail Removed)...
> I don't understand why most ADSL packages offer the same UPLOAD speed,
> and varying DOWNLOAD speeds. Is there some sort of technical contraint
> that explains the fact 256k download is the norm ?

this seems to be based on the ADSL "standard" in use.

If / when 8M ADSL (based on ADSL 2+) gets rolled out, the upstream best case
is 832 Kb/s
>
> Cheers
>
> --
> Darren
--
Regards

Stephen Hope - return address needs fewer xxs

(E-Mail Removed)lid wrote:
> I don't understand why most ADSL packages offer the same UPLOAD speed,
> and varying DOWNLOAD speeds. Is there some sort of technical contraint
> that explains the fact 256k download is the norm ?

Because BT chose to make it so.
There is essentially no other reason.