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#131268 - 05/13/03 12:39 AM Modem Speed?
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
Guys,
I've got a 56k Modem hooked up through my Phone line.
But when it comes to downloading stuff off the Net, the transfer rate is only 4-5kb/s and man is it SLOW!!.
Apart from getting an ASDL line(which costs mega-dollars,over here to install and access), how can I get faster downloads?.
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#131269 - 05/13/03 12:46 AM Re: Modem Speed?
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
Is that the "average" transfer rate reported by your software? If so, then part of that is the delay between packets coming through the net to your ISP.

At what speed are you actually connecting to your server?

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#131270 - 05/13/03 11:14 AM Re: Modem Speed?
ftl-eric Offline
Member

Registered: 01/16/02
Posts: 16
Loc: Schererville, IN
Trumpy,
When you say "4-5kb/s" do you mean kilobits (kb/s) or kilobytes (KB/s) per second? Windows typically reports downloads speeds in kilobytes.

The typically speed for a 56Kbps modem about 4.8 KB/sec.

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#131271 - 05/13/03 01:26 PM Re: Modem Speed?
Bjarney Offline
Moderator

Registered: 04/10/02
Posts: 2561
Loc: West-Southern Inner-Northeast ...
There’s not a lot in between dialup and cablemodem/ADSL. One is 2-way satellite, like Starband, but it’s expensive on the North American continent, and the latency will drive you mad… with the double 33,000-mile signal path to a geostationary bird.

ISDN/IDSL is a bit pricey, and limited to 64-144kb/sec but is consistently at that rate. Some less-populated communities in the western US have within-a-few-miles ”802.11” {radio} service, but it seems expensive, and only a little better than dialup speedwise.

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#131272 - 05/15/03 02:26 AM Re: Modem Speed?
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
Oh,
I was under the impression that a 56k modem had a transfer rate of 56KB/s.
Paul,
that's a really good question, I've seen something like 42.2KB/s(sound right?)mentioned on the screen when connecting.
ftl-eric,
Welcome to ECN, mate!,
Yeah, sorry about that, I meant Kilo-Bytes.
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#131273 - 06/07/03 04:30 AM Re: Modem Speed?
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
Paul,
Could you please tell me how ADSL differs from a standard Dial-Up connection?.
Why are these systems so expensive to get installed?.(and operate)
Do you need new wiring for these systems or are us people in NZ being led down the garden path?, so to speak.
Telecom in NZ is not exactly renowned for it's honesty being a Monopoly land-line company!.
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#131274 - 06/07/03 10:44 AM Re: Modem Speed?
ElectricAL Offline
Member

Registered: 10/10/01
Posts: 615
Loc: Minneapolis, MN USA
ADSL, asynchronous digital subscriber link.

I've been hooked up over two years now on ADSL.

Let's start with what you are looking at, these words on your screen, right now. You wish to reply to me so you use the mouse to push the "Post Reply" button. When your finger clicks the mouse button, a digital signal courses through the computer, is used to change the image on the screen, and is sent out through the phone line to the world wide web.

The digital signal from your mouse click stays digital from your computer through the phone line and on into the "cloud" of the internet on the ADSL connection. The modern dial up modems beginning with the transition to V.90 and later standards also do a direct digital transmission. The real difference is in the width of the band of frequencies allowed by the phone company for your specific line. Dial up is limited to a band of frequencies (bandwidth) that works well for carrying the human voice, and little else (that's why the music-on-hold always sound tinny). Dial up bandwidth can't be adjusted. So dial up simply can't get faster, now that we've used up all the mathematical compression and conversion tricks, with out a wider band of frequencies to send the signal into.

ADSL service provides a seperate band of frequencies above the frequencies used for voice. The higher band is used by the ADSL router for the digital information to go to and from the cloud of the internet and can be made wider or narrower, depending on how much you wish to pay for each month. As this band of frequencies doesn't interfer with the voice signal, both can be on the same single phone line. The voice line in your house is kept free of the whistle of the higher frequency digital "noise" with simple low-bandpass LC filters at each phone, or at the head of a wire that goes only to (a) phone(s). The computer ADSL router doesn't need a filter as it simply ignores the lower voice frequencies.

The phone wire that runs out the back of your computer, through the wall and down the road to the closest phone company office is metaphorically called "The Last Mile" and is where the greatest signal disruption occurs. The condition of your Last Mile is what determines whether the phone company can even supply ADSL to you, specifically, at all. The wire was manufactured and installed for low frequency voice signals. ADSL is higher frequency, and therefore, more susceptable to capacitive losses along the length of The Last Mile. Sopmetimes, the condition of The Last Mile restricts the speeds availabel to the slower ADSL rates. Sometimes, substituting a different line pair in the trunk will help. Sometimes, bits of hardware must be removed from your specific line. Sometimes, one must wait for the company to build an entirely new section of The Last Mile (if they ever will).
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#131275 - 06/07/03 12:09 PM Re: Modem Speed?
Bjarney Offline
Moderator

Registered: 04/10/02
Posts: 2561
Loc: West-Southern Inner-Northeast ...
AL — That's a very good description.

If I could add two comments..

An ADSL "voice grade" twisted pair (to the phone office) is supposed to have is up to 1.2MHz signal components. (!) That, and the one here is side by side with a pile of other voice [and T1] pairs.

Most important, though, is that ADSL is "packet switched" and not "circuit switched" like dial tone. That gives the appearance of being always connected. I’m very lucky to have a 15,105 ft pair and routinely get 1100kb/sec data rate. {It took the telco 7 months to get it working right.}




[This message has been edited by Bjarney (edited 06-07-2003).]

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#131276 - 06/08/03 06:35 AM Re: Modem Speed?
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
Well, I think Al has covered the ADSL/dial-up point very well there.

It really is that last connection (the "local loop") from your house to the CO that is the limiting factor these days. Many people living out in the sticks just don't have ADSL available to them. That "last mile" can also have a big effect on the speed at which you can connect on dial-up. A 56k modem is really pushing the limits of what can be crammed down a 3kHz wide telphone channel. I'm about 5 miles from my CO, and can generally connect between 42 and 44k, although it handshakes out at 38k on a bad day.

The difference between bits per second and bytes per second is also greater than the factor of 8 that you might think. On an asynchronous link you have not only the 8 bits for each byte, but also a start bit and a stop bit, so at full tilt 56 kilobits per sec could give you an absolute maximum transfer rate of 5.6 kilobytes per sec (before any compression is applied).

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#131277 - 06/08/03 07:20 PM Re: Modem Speed?
Scott35 Offline

Broom Pusher and
Member

Registered: 10/19/00
Posts: 2724
Loc: Anaheim, CA. USA
Can't wait until I can afford to go ADSL here at home! Plan to connect the ADSL Brouter to the LAN Switch and share with all Workstations!
But then I need to play Netgeek at home - + Firewall the whole thing!

At least, would be nice to have one W/S on a Dynamic IP ADSL connection, until the 5 Static IP addresses rate drops to something affordable.

Until then, I am still pushing data via Analog V90 MODEM connection - which top speed is 45,333 BPS, equaling upto a highest download speed of 6.5 KBPS (Kilo Bytes). That includes all the parity stuff and ack-ack (RTS/CTS and etc.).

Much nicer than my previously used V34 / 28.8 KBPS connection, which I used from 1996 upto 2001!

Scott35
_________________________
Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

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