Long Distance ADSL ???

[ol' boy]

OK, it was always my understanding that an ADSL connection over a pair of copper (phone line) was at a terminal distance of 4K's from the exchange.

This has meant the headaches of VSAT, 3G and external antennas etc for those out of this 4k radius.

I just went to a friends country property and bugger me, Telstra came and installed a bog standard Thomson ADSL WiFi modem!
The property is 8k's from town
I checked his speed, was awesome, Ping time 44ms and download was 1.3Mg on their 1.5mg plan.

Apparently according to my friend, they went outside and put something in the line??? An amplifier perhaps?

Anyway, just wondered if anyone here had heard anything similar?
Is it just a Telstra option or would this perhaps let my friend shop around.

This will solve a problem for so many of my clients. And what is to say that 8k is the limit, it worked so well, who knows how far out you can go?

[tagg]

i am 7.2k from my exchange and i have ADSL fair enough i only get between 1.5 and 2m on a good day, according to my ISP it should not be working lol

Tagg

[urban_s0ulja]

It comes down to the quality of the lines more than distance.

[porkop]

I get ADSL2+ 15Mbit/s.....sorry couldnt resist!!

[marty 17]

As I cannot get Adsl and only live 4.45 km cable length from the exchange I would appreciate if Tagg could let me know his Isp and oceanboy let me know what they put outside at his friends house.

For urbans benefit the length of cable and conductor weight are the 2 most critical aspects of the cable for Adsl
Marty

[RHCP]

It comes down to the quality of the lines more than distance.

True - Attenuation is only relative to distance. Some countries use much thicker cables, and so can provide excellent quality ADSL at considerable distance.

I have read a couple posts of others (farmers/rural properties) getting decent speeds with long line distances.....some people replied saying they may have newer or thicker cables?

With ADSL2+ or ADSL2 Reach, you can expect to see 1Mb/s or so at 6km (or 80dB of attenuation). Also, some modems (chipsets) can handle long lines considerably better than others.....

Could they have installed a central line filter?

Cheers.

[tagg]

As I cannot get Adsl and only live 4.45 km cable length from the exchange I would appreciate if Tagg could let me know his Isp and oceanboy let me know what they put outside at his friends house.

For urbans benefit the length of cable and conductor weight are the 2 most critical aspects of the cable for Adsl
Marty

Mate i am with Iprimus and have a central splitter installed, now i had no end of hassle with them over the service when it dropped out for a week, it took nearly a month of bitching and phone calls to get it back, they have good coverage now so you maybe lucky they could be in your exchange.

Tagg

[ol' boy]

True - Attenuation is only relative to distance. Some countries use much thicker cables, and so can provide excellent quality ADSL at considerable distance.

I have read a couple posts of others (farmers/rural properties) getting decent speeds with long line distances.....some people replied saying they may have newer or thicker cables?

With ADSL2+ or ADSL2 Reach, you can expect to see 1Mb/s or so at 6km (or 80dB of attenuation). Also, some modems (chipsets) can handle long lines considerably better than others.....

Could they have installed a central line filter?

Cheers.

Wasn't a central filter in my friends case, he has a filter at each phone and each Foxtel box.

No idea what they put out side

[tarwin]

Another option in the bush and with a friend in town that has adsl, is to push the signal out via wifi. Line of site is essential it won't work for everyone but has for me for 6 years. 12.5 k from town I have 8000kbs without a problem. Even further is possible with the right equipment but great speeds can be achieved with off the shelf devices up to 15k or so.

[intelliGEORGE]

I live 250m (as the crow flies) from my exchange. I am still pissed I can't max my connection at 24Mb/s as the bastard line only allows me 20.

[mitaux8030]

ADSL is basically sending RF (radio signals) down copper twisted pair lines. And it has many similarities to radio too... attenuation, or how quickly the signal reduces in strength, isn't the only factor. Interference & noise is another big determining factor too. Things like crosstalk, impulse noise & external noise sources also cause problems. Even if an ADSL signal is strong, a nearby noise source can wipe it out.

There's not a lot you can do about attenuation, so long as all the cable joints are of decent quality, that is no high resistance joints. Sometimes you can hand-pick a 'pair' within the cable that offers slightly lower attenuation, but more often you'd be picking it for best noise.

In the suburbs, most telephone cables are underground and so are fairly well shielded from external noise sources until the copper cable reaches your house. It will be the configuration of your house cabling and noise sources within your home that will be the major determining factor of performance due to noise. Corroded terminal blocks, poor internal cabling runs (perhaps DIY extensions), noisy switchmode power supplies, plasma TVs etc. can all have a detrimental effect to ADSL performance.

In the remote areas where population density is far less, noise from external sources is much less of a problem, and line condition with respect to joint resistance, cable balance, crosstalk etc are more the limiting factors. So with good condition pairs, ADSL can travel further than normal, out in the boonies.

Another factor could be the modern day line concentrator. Its a bit like a mini telephone exchange located remote from the real telephone exchange. In days of old, the old line concentrators couldn't handle ADSL signals. The new day concentrators (which is really the wrong term for them) are more like mini exchange nodes, and have their own mini DSLAM installed within them etc.

Another thing not often appreciated by consumers is that ADSL modems ain't ADSL modems (with apologies to Castrol for their 'oils ain't oils' slogan). Some ADSL modem chipsets are more capable than others, just as some mobile phones work better with weak signals than others, just as a Rolls Royce is generally a better car than a Kia is.

As for central filters, unless the installation is particularly difficult, I usually go this way. If you install the central filter as close to the point-of-entry as you can, and split off the ADSL signal before it has the chance to be influenced by existing poor cabling runs/joins/etc. then you can run the ADSL signal in a brand new cable, running it as far away as practical from electrical wires or other potential sources of noise, then you have the best possible chance of avoiding interference to the ADSL signal. Having said that, in my own home the computer desk and ADSL modem is located next to the entertainment unit where one of the worst offenders for interference to an ADSL signal lives in said entertainment unit: a whopping big plasma TV. Sometimes its just unavoidable. I could install the ADSL modem at the central filter, and run ethernet cables to the PC outlets... that would be better, but my ADSL signal isn't that marginal to warrant the effort.

A combination of all the above goes a long way to explaining why sometimes you get much less than you expect given the circumstances, or why sometimes you get suprisingly more than you'd have thought. Despite the 'digital' nature of the broadband service being delivered, there's still very much an 'analogue' component that delivers it to your doorstep, and is thus influenced by all the usual analogue factors.