Hardware & Devices

7-Apr-08 2:37

IIRC silent PC review found the raptors noise on par with an average 7200rpm drive. It was still louder than the quieter models though.

You know, every time I tried to win a bar-bet about being able to count to 1000 using my fingers I always get punched out when I reach 4....
-- El Corazon

DSL question

David Crow4-Apr-08 4:01

David Crow

4-Apr-08 4:01

When I signed up for DSL, I opted for the 1.5M package. After all the dust settled, I checked the speed using several sites. All of them reported the speed to be around 1.3M. I know the basic reason why it wasn't the full 1.5M, but I wanted to ask just to be sure, and to see if any more could be gotten out of it. The three big factors they gave were: 1) distance from the DSLAM/CO, 2) noise in the line, 3) equipment. At this point, we know that it's possible to get a 1.3M connection speed to my house. Note that I am not concerned with the difference between 1.3M and 1.5M.

For price reasons, I recently switched to the 768K package. When I again checked the speed, it was roughly 680K. Herein lies the question: why are they not providing a full 768K connection when it has already been proven that a 1.3M connection is possible? If I were to call them and ask, I can only assume they'd give me the same three reasons as above.

- DC

"Love people and use things, not love things and use people." - Unknown

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

code-frog4-Apr-08 5:02

4-Apr-08 5:02

Other answers may differ... a lot!

But my experience has been that these are environmental factors in most cases. If you do some google on the ping command you can add some optional switches that show packet loss and some other information. Line overhead is another.

But when you say you signed up for 1.5 megabit that tells me that the best download rate you could hope for in perfect conditions is ~150Kbps sustained. Now when you report you are only getting 1.3 megabit in perfect conditions you will average ~130Kbps sustained. So in affect we are talking roughly a ~20Kbps differential and in my experience that is nothing to worry about.

Now if you want to understand what factors influence your speed they are right in what they told you.

* Distance.
* Line quality.
* Hops.
* Splices. How many times is that signal being filtered and optimized along the way.
* Moisture. Heavy rainfall or humidity will affect speed if water is getting to copper anywhere.
* Unplug everything at home (phone, fax, other PCs, etc...) then test again.

For 20Kbps you could spend a lot of time and even more money to understand what is going on. Also speedtests are *NOT* extremely accurate and I'd be willing to suggest that your "test results" will vary hugely just based upon different times of day.

Ideally you'd want to test on a freshly formatted machine with it being the only thing on the local network. You'd want the server testing against to be the only server on the web at the time you test. You'd want the weather all over the world to be perfect and so on... and so on...

For a variance of ~20Kbps I'd not worry. That sounds pretty good to me. I know that broadbandreports.com and dslreports.com have some really good information on this topic and you should be able to learn more than you ever wanted if you visit those sites.

Rex

David Crow4-Apr-08 5:09

David Crow

4-Apr-08 5:09

code-frog wrote:
So in affect we are talking roughly a ~20Kbps differential and in my experience that is nothing to worry about.

I was never worried about it. A 1.3M connection was perfectly fine, and not at all related to my concern.

"Love people and use things, not love things and use people." - Unknown

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

code-frog4-Apr-08 5:35

4-Apr-08 5:35

No and I understand that. For you the exercise is probably more educational than anything else. If it is then have at it. My take was to say that I often see real people in the real world throw hundreds if not thousands at something like this just to get that ~20Kbps.

Now if you are just wanting to understand why (and I took that as your meaning) I think that BBR is the way to go. They have tons and tons and tons and tons of good material on it. Surprising... if you can find it... Microsoft has even better literature (IMO) than what you find at places like BBR.

I just did about 10 minutes of searching and am not feeling really satisfied by anything I found. If I were you another place with good information is at Fluke Networks. Look up LinkRunner Pro and then register at their site. They have some really good white papers that talk more about this subject and I've enjoyed what I have read so far.

http://www.flukenetworks.com/fnet/en-us/[^]

The KB there is pretty darned good.

Dan Neely4-Apr-08 6:46

4-Apr-08 6:46

Wild guess, but noise spikes in the line resulting packets failing a checksum and needing resent?

You know, every time I tried to win a bar-bet about being able to count to 1000 using my fingers I always get punched out when I reach 4....
-- El Corazon

code-frog4-Apr-08 7:46

4-Apr-08 7:46

How is he going to measure that short of some expensive tools that can test for that type of thing? Is there an easy way to check that?

Dan Neely4-Apr-08 8:04

4-Apr-08 8:04

Unless the modem has a debug mode that shows it probably not.

You know, every time I tried to win a bar-bet about being able to count to 1000 using my fingers I always get punched out when I reach 4....
-- El Corazon

Pete O'Hanlon7-Apr-08 11:02

Pete O'Hanlon

7-Apr-08 11:02

Rex - come back to the lounge. We miss you - honestly.

Deja View - the feeling that you've seen this post before.

My blog | My articles

Mike Dimmick10-Apr-08 10:11

Mike Dimmick

10-Apr-08 10:11

Here in the UK the quoted line speed is the ATM transit speed - we use PPP over ATM (PPPoA). There's overhead on top of that to actually support a DSL link. So my quoted speed of 8168kbps reported by the router is actually about 7.5Mbps usable speed. Maybe your provider is doing the same.

(I live about 100m from my telephone exchange.)

DoEvents: Generating unexpected recursion since 1991

David Crow10-Apr-08 15:39

David Crow

10-Apr-08 15:39

Mike Dimmick wrote:
Maybe your provider is doing the same.

Like I've already indicated, I know the reason why there's a difference between advertised and actual speed. That's not my question.

"Love people and use things, not love things and use people." - Unknown

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

code-frog10-Apr-08 15:45

10-Apr-08 15:45

DavidCrow wrote:
Herein lies the question: why are they not providing a full 768K connection when it has already been proven that a 1.3M connection is possible?

I it's due to the line configuration. See if ADSL has built in overhead. I think it actually does. There may be an automatic percentage in loss simply because of the asymmetric nature of the lines. I'm not sure of this either but perhaps they run the lower speed off other equipment.

Optionally you may have spyware or malware that is using bandwidth you just cannot see. If it's rootkitting on a machine you will never know. You'll see a bandwidth hit. Have you tried doing packet capture to see? Put another device between your router and the DSL modem and make sure that device has two NICs and can do packet capture. You might be surprised but what you find.

#realJSOP11-Apr-08 3:06

#realJSOP

11-Apr-08 3:06

It's not "noise", it's not "distance from the DSLAM". The plain and simple truth is that it's FRAUD.

The say "up to" 1.5M down, but truth in fact, you'll NEVER see 1.5M down because there is a speed overhead that they force YOU to soak up. They only say "up to" because that's what they have your connection throttled to. The same goes for cable ISPs, so don't assume that switching to another provider is going to solve the underlying problem.

The long and short of it is that we're being ripped off.

code-frog15-Apr-08 3:30

15-Apr-08 3:30

The one that gets me angry is hard drive size. Yeah sure it says 750 gigs but once it's in and running actual size is more like 700 and generally a lot less. That's the rip-off!

Dan Neely15-Apr-08 4:33