They Have upgraded me to 4Megs

J

JAS

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Apr 12, 2004
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131
There is a possible negative aspect to upgrading to a higher speed. Higher sync speeds require less line attenuation and better noise margins, so if you are quite far from your exchange you may start experiencing connection problems.
 
K

KinsZA

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May 23, 2005
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1,094
u lose 5 snr per megabit btw.

Pity this is only going to go live on 1 september, I mean I see my syncing at 4mbit and my 1 mbit speeds.

Email'd isps, they say that cannot and/or will not limit.
 
D

dabouncer

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Jan 2, 2006
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Still 1mb speeds. Sounds like Telkom needs to increase the "allowed" speed on the lines, this i recon will happen around 1 September. Im still pretty chuffed that ill be able to try out a 4mb line next month. Yay for me and Yay for Telkom. :)
 
R

rasputyn

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Apr 4, 2004
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Ok, someone please explain this to me, my exchange is about 2km from my place by road, but obviously I don't know the actual distance on the wire from here to the exchange. My modem is telling me this

ADSL Link
Connection Speed: Down:640 kbps Up:384 kbps
Line Attenuation: Down:30 db Up:8.5 db
Noise Margin: Down:27 db Up:12 db
Click to expand...

Now, this is something I don't know much about, in terms of attenuation, what is better, a high number such as 30db or a low number like 8.5db??

An for noise margin, what is better, high or low??

I'm guessting low is better on both on both counts??
 
bwana

bwana

MyBroadband
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rasputyn said:
Ok, someone please explain this to me, my exchange is about 2km from my place by road, but obviously I don't know the actual distance on the wire from here to the exchange. My modem is telling me this



Now, this is something I don't know much about, in terms of attenuation, what is better, a high number such as 30db or a low number like 8.5db??

An for noise margin, what is better, high or low??

I'm guessting low is better on both on both counts??
Click to expand...
Good question - wish I could answer it without guessing so I wont.

Have you tested what your line should be capable of? http://212.23.23.177/calc.htm - I take it you're on a 512 at the moment?
 
R

rasputyn

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Thanks bwana, was trying to find that link!

Edit: A crude estimate of what your line is capable of is 3525kbps (kilo bits per second). I'd still like to know how it works, anybody, please?

Edit2: Ok, I think I figured it out, I played with that calculator, and the higher the attenuation and margin you put in, the faster your speed becomes.
 
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G

Gambit

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rasputyn said:
Ok, someone please explain this to me, my exchange is about 2km from my place by road, but obviously I don't know the actual distance on the wire from here to the exchange. My modem is telling me this



Now, this is something I don't know much about, in terms of attenuation, what is better, a high number such as 30db or a low number like 8.5db??

An for noise margin, what is better, high or low??

I'm guessting low is better on both on both counts??
Click to expand...

You want the line attenuation to be as low as possible and signal to noise ratio to be as high as possible.
 
D

Daveogg

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Nov 11, 2003
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Low attenuation high noise margin is what you want.

Think you in a room and everyone is talking at once. The general volume of noise is your attenuation. If someone is now shouting, how much louder he is than the rest is the noise margin. If the noise margin is high then you should be able to hear him clearly.
 
Y

Yuu

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Apr 3, 2006
Messages
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That calc on that site aint doing it right for me :(

bwana v.16 said:
Have you tested what your line should be capable of? http://212.23.23.177/calc.htm - I take it you're on a 512 at the moment?
Click to expand...

Oh great Bwana please assist me in getting this calc to work as i enter 1024 and attenuation=45 & SNR=5 i get exactly what i put in = 1024 or if i put 3000 i get 3000 ??

I have been for awhile on 1mb and am less than 1.5km away however i must check this to be absolutely sure and getting disconnected frequently so maybe there is a way to reduce attenuation [i know not completely but a little helps]?

Thanks for your time & assistance and btw i was pushed with the upgrade after 2pm yesterday and atm on 2336kbps line speed but offcourse no ISP speed upgrade yet.

again thanks and look forward to any help.

Yuu
 
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