ADSL attenuation different for up and down

I have got 30dB attenuation upstream, and 58-60dB attenuation downstream - is this normal? It would look to me that there is 1000 times (30 dB) less signal coming to me from the exchange than from me TO the exchange. The BT engineer's eyes didn't pop out at this point though.

--
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For the really paranoid who want to destroy data there's nothing like taking the lid off the disk drive and rearranging the sectors with a hammer.

On Mon, 07 Jun 2004 09:59:30 +0100, "Peter Hucker"
<(E-Mail Removed)> wrote:

>I have got 30dB attenuation upstream, and 58-60dB attenuation downstream - is this normal?

Yes.
--
John Naismith

On Mon, 07 Jun 2004 09:59:30 +0100, Peter Hucker <(E-Mail Removed)>
wrote:

> I have got 30dB attenuation upstream, and 58-60dB attenuation downstream
> - is this normal? It would look to me that there is 1000 times (30 dB)
> less signal coming to me from the exchange than from me TO the
> exchange. The BT engineer's eyes didn't pop out at this point though.
>

Hi,

It is perfectly normal to have different figures for upstream and
downstream line loss. In fact I would expect it.

--
Regards,

| Dave Tomlinson Broadband Solutions For
| Technical Support for Home & Business
| PlusNet Technologies Ltd. @ http://www.plus.net
+ ----- My Referrals - It pays to recommend PlusNet -----

"Peter Hucker" <(E-Mail Removed)> wrote in message
newspr87u9gvdaiowgp@blue...
> I have got 30dB attenuation upstream, and 58-60dB attenuation downstream -
is this normal? It would look to me that there is 1000 times (30 dB) less
signal coming to me from the exchange than from me TO the exchange. The BT
engineer's eyes didn't pop out at this point though.
>
> --
> 11 parrots http://www.petersparrots.com
> 93 silly video clips http://www.insanevideoclips.com
> 1259 digital photos http://www.petersphotos.com
>
> For the really paranoid who want to destroy data there's nothing like
taking the lid off the disk drive and rearranging the sectors with a hammer.

Downstream carriers are higher frequency than the upstream - I'd say the
attenuation difference was normal based on the frequency response of the
pair alone.

Colin

On Mon, 07 Jun 2004 10:25:28 +0100, PlusNet Support Team <(E-Mail Removed)> wrote:

> On Mon, 07 Jun 2004 09:59:30 +0100, Peter Hucker <(E-Mail Removed)>
> wrote:
>
>> I have got 30dB attenuation upstream, and 58-60dB attenuation downstream
>> - is this normal? It would look to me that there is 1000 times (30 dB)
>> less signal coming to me from the exchange than from me TO the
>> exchange. The BT engineer's eyes didn't pop out at this point though.
>>
>
> Hi,
>
> It is perfectly normal to have different figures for upstream and
> downstream line loss. In fact I would expect it.

!! support from my own ISP in here :-) Now that's service.

Can you (or someone) explain how there can be such a marked difference? I'f I'm sending 256kbps with only 30dB loss to the exchange, can't the exchange slow down a bit and cut it's loss too?


--
11 parrots http://www.petersparrots.com
93 silly video clips http://www.insanevideoclips.com
1259 digital photos http://www.petersphotos.com

A "Frisbeterian" believes that when you die, your soul goes up on the roof and you can't get it back down.

On Mon, 7 Jun 2004 12:46:07 +0100, Colin <(E-Mail Removed)> wrote:

>
> "Peter Hucker" <(E-Mail Removed)> wrote in message
> newspr87u9gvdaiowgp@blue...
>> I have got 30dB attenuation upstream, and 58-60dB attenuation downstream -
> is this normal? It would look to me that there is 1000 times (30 dB) less
> signal coming to me from the exchange than from me TO the exchange. The BT
> engineer's eyes didn't pop out at this point though.
>>
>> --
>> 11 parrots http://www.petersparrots.com
>> 93 silly video clips http://www.insanevideoclips.com
>> 1259 digital photos http://www.petersphotos.com
>>
>> For the really paranoid who want to destroy data there's nothing like
> taking the lid off the disk drive and rearranging the sectors with a hammer.
>
> Downstream carriers are higher frequency than the upstream - I'd say the
> attenuation difference was normal based on the frequency response of the
> pair alone.

Pity they aren't adjustable. I'd prefer a 256kbps downstream if it stayed on!



--
11 parrots http://www.petersparrots.com
93 silly video clips http://www.insanevideoclips.com
1259 digital photos http://www.petersphotos.com

I like to pick up hitchhikers. When they get in the car I say:
"Put on your seat belt. I want to try something. I saw it once in a cartoon, but I think I can do it." -- Steve Wright

Peter Hucker wrote:
> On Mon, 07 Jun 2004 10:25:28 +0100, PlusNet Support Team
> <(E-Mail Removed)> wrote:
>
>> On Mon, 07 Jun 2004 09:59:30 +0100, Peter Hucker <(E-Mail Removed)>
>> wrote:
>>
>>> I have got 30dB attenuation upstream, and 58-60dB attenuation
>>> downstream - is this normal? It would look to me that there is
>>> 1000 times (30 dB) less signal coming to me from the exchange than
>>> from me TO the exchange. The BT engineer's eyes didn't pop out at
>>> this point though.
>>>
>>
>> Hi,
>>
>> It is perfectly normal to have different figures for upstream and
>> downstream line loss. In fact I would expect it.
>
> !! support from my own ISP in here :-) Now that's service.
>
> Can you (or someone) explain how there can be such a marked
> difference? I'f I'm sending 256kbps with only 30dB loss to the
> exchange, can't the exchange slow down a bit and cut it's loss too?

What the hell is this doing in here? It's totally off topic!

Steve

On Mon, 07 Jun 2004 12:59:34 +0100, Peter Hucker <(E-Mail Removed)>
wrote:

> On Mon, 07 Jun 2004 10:25:28 +0100, PlusNet Support Team
> <(E-Mail Removed)> wrote:
>
>> On Mon, 07 Jun 2004 09:59:30 +0100, Peter Hucker <(E-Mail Removed)>
>> wrote:
>>
>>> I have got 30dB attenuation upstream, and 58-60dB attenuation
>>> downstream
>>> - is this normal? It would look to me that there is 1000 times (30 dB)
>>> less signal coming to me from the exchange than from me TO the
>>> exchange. The BT engineer's eyes didn't pop out at this point though.
>>>
>>
>> Hi,
>>
>> It is perfectly normal to have different figures for upstream and
>> downstream line loss. In fact I would expect it.
>
> !! support from my own ISP in here :-) Now that's service.
>
> Can you (or someone) explain how there can be such a marked difference?
> I'f I'm sending 256kbps with only 30dB loss to the exchange, can't the
> exchange slow down a bit and cut it's loss too?
>
>

The main factor is the frequency range that each part of the signal uses.
Essentially the frequency range is divided into 3 parts for voice,
downstream and upstream and each is affected by conditions differently.
The chart on this page

http://www.ieee-occs.org/presentatio...ite/sld006.htm

shows roughly how it divides up.


--
Regards,

| Dave Tomlinson Broadband Solutions For
| Technical Support for Home & Business
| PlusNet Technologies Ltd. @ http://www.plus.net
+ ----- My Referrals - It pays to recommend PlusNet -----

"Peter Hucker" <(E-Mail Removed)> wrote in message
newspr873lkouaiowgp@blue...
> I'f I'm sending 256kbps with only 30dB loss to the exchange, can't the
exchange slow down a bit and cut it's loss too?

You mean could BT deploy RADSL downstream, as well as upstream?

Yes, they could but BT have actively chosen not to do this.

Several reasons, including the fact that it has been done in many other
countries (i.e. North America) - only for the telco's their to get many
complaints about "my neighbours can download faster than I can and we are on
the same (rated) speed service"

It also means that BT can't guarantee the QoS on their network then and sell
related products

Regards
Sunil

In article <opr873swkhaiowgp@blue>, Peter Hucker <(E-Mail Removed)>
writes
>On Mon, 7 Jun 2004 12:46:07 +0100, Colin <(E-Mail Removed)> wrote:
>> Downstream carriers are higher frequency than the upstream - I'd say the
>> attenuation difference was normal based on the frequency response of the
>> pair alone.
>
>Pity they aren't adjustable. I'd prefer a 256kbps downstream if it stayed on!
>
>
>
aren't there reasons why the crosstalk is much less of a killer this way
round?
--
robert w hall