# ADSL speeds

## grant123

AT&T seems to be phasing out DSL service so I can't add more bandwidth.  DSL Extreme will sell me a maximum of 12Mb downstream and 1Mb upstream (bits, not bytes).  What should I expect as far as real world speeds?

BTW, DSL Extreme requires that I use their modem even though I already have a DSL modem I like.  Can their network really prevent me from using a different modem?

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## eccerr0r

Off topic but oh well.  Probably should be an OTW post.

I'm still stuck with DSL.  Anyway, rule of thumb, I just divide the Mbits/sec by 10, it's pretty close to what I see.  The real number of MBytes/sec is slightly higher than the Mbit/sec divided by 10.

And yes there are lots of different DSL codings out there.  I know my modem does not support the high speed 40MBit DSL, so I can expect to have to swap modems once they swap their DSLAM...

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## grant123

Thank you.  So cable internet is wiping out DSL?

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## Cus

I did some time at an ISP here in australia, an "Annex M" DSLAM will top out at 20Mbit/s down and 2mbit/s up, as noted, divide that by 10, and that's your KB/s speed.

The actual speed of the service is determined by your distance from the DSLAM (telephone exchange) and the quality of the phone line. An easy win, if possible, is to use the shortest phone line from the wall to the modem you can, long (2M / 6ft) extension leads will start to deteriorate speeds really quick. run a long ethernet to the modem if you need to move it, it deals with better with long runs than a phone cable.

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## eccerr0r

Yes, cable seems to be blowing away DSL in terms of speeds - there's only so much you can do with poorly shielded twisted pair versus a shielded RG59... I just can't get static IPs with cable...

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## NeddySeagoon

In the UK, ADSL+ (20Mbit/sec max) is being overtaken by Fibre to the Cabinet/curb.

The fibre is is the same duct an the phone line but only the last hop from the fibre to the home is over the phone line. VHDL.

The hardware is capable of 100Mbit/sec down 20Mbit/sec up but its being sold as 80/20 or 40/20 depending on what you want to pay.

Fibre to the premises is on trial in the UK.  That's 330Mbit/sec down and 30Mbit sec up. I can't get that yet though.

A 1G downlink is being rumoured too.

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## grant123

Nice tip on the phone cable length.  I'll check on that.

Are static IPs a problem with all cable ISPs?

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## NeddySeagoon

grant123,

If you are in the UK removing the ring wire applies to you.

You are allowed to do this as its connected on your side of the NTE5 faceplate.  

If you are not in the UK, you might not even have a ring wire. 

It got me a a 25% improvement in by ADSL speed from just over 3 Mbit/sec to just over 4Mbit/sec.

The ring signal is provided by the ADSL filers, so need not be distributed from the master socket.

When you do this, it will take 10 days  for the line speed improvement, which you can see almost instantly on your modem web pages, to translate into faster data rates. That's the time it takes for your BRAS profile to update.  If you don't want to wait, phone your ISP and ask them to reset your BRAS profile.  Then your line will undergo learning form new again.  

The BRAS profile is what stops your ISP accepting data into their network faster than they can actually deliver it to you.

If they did that, they would have to drop the excess packets and clog up the internet requesting them again.

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## grant123

Thanks NeddySeagoon.  So being in the US I may still need to remove the ring wire?  I'll take a photo of my phone jack's wiring and post a link here.

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## eccerr0r

There is no "ring" wire in the US, they are just twisted pairs as much as I can tell.  Ring is done in band (and I have had problems in the past where DSL would drop when someone calls POTS.  It seems to be fixed now).

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## Tony0945

 *grant123 wrote:*   

> Are static IPs a problem with all cable ISPs?

   No, WOW will give you a static IP if you ask and possibly pay a fee.  Maybe others will too.  I have an effectively static IP. I leave the cable modem on usually and the lease times are long so that my IP has not changed for two years.

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## eccerr0r

I have not been able to find a cable provider in my area that would offer a static IP and has reverse-DNS for a reasonable fee.

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## NeddySeagoon

grant123,

In the UK, the POTS is powered by 48v DC.  Exchanges used to have rooms full of lead acid batteries to keep the POTS going through power cuts. The voice signal is carried on top of that. It actually energised the handset microphone.  In days of old, the 48v C powered the phone too.  That still works if you have a hard wired phone.

The ring signal is approx 50v AC superimposed on the 48v DC.  Its split off in the customer premises by a capacitor that feeds the bell wire.

Yep, it really was a bell.

For completeness, the UK POTS is still backwards compatible ... right back to pulse dialling.

Sadly, 'tapping out' no longer works with the phasing out of mechanical exchanges.

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## grant123

Is it worth inspecting the wiring in the phone jack at my US location or don't bother?

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## NeddySeagoon

grant123,

Looking is free - but might be illegal.  

See what the web says for improving your ADSL speed in the US.

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## krinn

just copy the wires scheme, do tests, and re-use scheme to rebuild original wiring.

in france, we use to have 4 wires in old days, but 2 were only need to get tone and dsl sync, the 2 others were a backup line.

Today (here) when you ask to get phone, they come and wires only 2 now.

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## grant123

Here is the very old phone jack device at my location in the US.

https://ibin.co/39Rq5EJuXDGS.jpg

Can anything be done with this to increase DSL speeds?

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## ct85711

A lot of the time for DSL speeds in the US, is primarily limited by the distance from your ISP junction point to your place in that the longer the distance, the slower the speeds.  Quite frankly, if the speed available coming up to your house is slow, it doesn't matter what you do in your house as it will only have at best that speed coming up to your house.  This means, you need to have your ISP test the line and measure what is the most you can even get coming to your place to see if you can even get a better speed.

Now on your side, some other factors that will affect your speed is multiple things.  First off, how old is the wiring in your house?  The older the wiring, the more noise in the line and less strength.  Next, how many splitters (i.e. wall jacks included) do you have on your phone line; as that too reduces your signal strength and can cause more noise.  You know those filters the ISP gives you, those too cause you to loose signal strength and possibly cause some noise.  After all that, then you get into your modem from the ISP on what that can even handle.

Either way you go, unless you are willing to speed a lot of money to having the wiring redone; there is not much you can do about your internet speed with DSL.  I know I tried getting a better speed myself, the ISP been saying that I should be able to get 40-50M.  However, because my house is so old, the best I can get is 10M; I can barely get caller ID to work all the time because if the noise and signal strength loss I have.

Best bet either way, is either go with cable internet or get the fiber internet if it's available.

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## eccerr0r

My $%*#$$$*$$#@$ ISP (the $ symbols are numerous not solely because of self censorship) won't upgrade the DSLAMs so that I can get 40Mbit+... 

I do live on the outskirts of the DSLAM CO I think, over a mile or so, though I'm not sure if I could get a better bitrate with a better encoding scheme.  I'm stuck with the older G.DMT and have been stuck with it since changing from the even older CAP encoding standard.

I had a VDSL/ADSL2 modem that went flaky.  Now I'm using an older ADSL2 modem which is still supporting a higher standard than the DSLAM supports.

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## grant123

How can I figure out if my modem hardware is holding me back?

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## ct85711

grant, first off call your ISP and find out what the max speed you can even receive to your house.  Quite often they can run the test on their side and tell you what you can receive.

After that, you can start talking to them on upgrading your internet package to an higher speed, they will either replace your internet modem (or tell you what models you can use).  Depending how old your modem is, it is unlikely to be your limiting factor assuming it is relatively new (say within last 5 or so years).  You are not going to get more speed without paying for it.  It is pretty safe to assume, that you won't get a faster speed in the UK too without paying for it.

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## grant123

Lots of conflicting info here.

Also, AT&T wants everyone in my area to switch to cable but I cant get cable at my particular location.  They refuse to upgrade my DSL plan and just try to sell me cable.

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## NeddySeagoon

grant123,

Look at the line stats you can probably find on an admin page on your router.

It will tell things like line speed, signal to noise ratio.

Post your router make/model so I can get a copy of the manual.

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## ct85711

The part I think you are getting mixed up on is the US and UK (European) standards which works differently (can concept, but different method).  The main thing you need to remember is that there is no way you are going to get a faster speed for nothing; as the ISP controls the speed you can receive.

Note:  I am no way trying to say which standard is better, nor do I care.

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## NeddySeagoon

ct85711,

The ADSL physics is such that in the UK, ISPs sell an "Up To" speed.  Its the sort of speed you get on about 50 yards of phone wire.

They do not sell a fixed speed.

The speed drops off with (phone line) distance from the exchange but you still pay the same.

ADSL(2+) will work with a 3db S/N ratio.  If its higher than that, you can get some more speed.

Its its a lot higher like 12db, there is probably a problem.

However, the S/N is affected by things like season of the year and time of day, as well as all the things connected to the phone line. 

There are some very ugly graphs of ADSL not working very well.

I eventually rewired the house side of the master socket to fix it.

The images are created with rddtool by sampling the line data from the router every 5 sec.

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## eccerr0r

And in the US, most of them at least in the past have sold fixed rates in order to have room for upselling.

DSL however is being out-competed by cable, so they were likewise forced in some instances to switch over to "fast as possible" and give bandwidth limits.  Plus they won't have to worry about QoS questions like "my DSL is only 3Mbit but you said 20Mbit"...

Before they'd have to send out a technician to try to diagnose the line.  Now it's your fault...

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## grant123

 *NeddySeagoon wrote:*   

> Look at the line stats you can probably find on an admin page on your router.
> 
> It will tell things like line speed, signal to noise ratio.
> 
> Post your router make/model so I can get a copy of the manual.

 

The modem is a Westell 6100.

I will get the line stats tomorrow.

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## NeddySeagoon

grant123,

Eww ... the manual I found is dated July 2004.

That's probably ADSL at that age, not ADSL2+.  However if your ISP only provides ADSL, there is no point in you getting an ADSL2+ modem because it won't go any faster.

Cheap microfilters are a bandwidth killer.  They come in two mechanical constructions. A small box with a pigtail, or a single self contained 'doofer' that plugs into the phone socket.  The latter are a waste of money - there isn't enough room to put a decent filter in that space.  Those are just illustrations of what to look out for. You get what yo pay for.  Its worth paying the extra for 'Active Microfilters'

Its easy to test but to avoid outcry from other family members, you might want to wait until you are home alone.

On the router, bring up the line stats page and make a note of the Signal to Noise Ratio and down stream data rate.

Now go around the house and unplug all the microfilters from the telephone jacks, so only the router is left connected.

What happened to the Signal to Noise Ratio and down stream data rate now everything is disconnected?

The change is due to the microfilters not loading the DSL signal.  That gives you some idea of the best that you can achieve.

You may want to power cycle the router to force it in reconnect to the exchange.

Also, microfilters fail from time to time.  Sometimes its not easy to detect. The failure mode just reduces the ADSL bandwidth.

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## grant123

This page claims the Westell 6100 supports ADSL2+:

https://www.amazon.com/Westell-6100-ADSL2-Modem-Router/dp/B000QPPY0A

This looks to be the highest rated DSL filter on Amazon:

https://www.amazon.com/In-line-DSL-Filter-w-Splitter/dp/B003807GK6

Should that one be OK?

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## NeddySeagoon

grant123,

It appears that the Westell 6100 has changed over the years.  The one in your link certainly provides ADSL2+

Ordinary ADSL can deliver up to 8Mbit/sec.  ADSL2+ is up to about 20Mbit but the extra 12Mbit is carried on higher frequencies (shorter range) that the original ADSL signal.

In other words, ADSL2+ won't help unless you can max out ADSL.  Also, your ISP has to provide ADSL2+ at their end.

Don't be in a hurry to replace your microfilters.  Do the test first. 

The router alone does not need a filter.

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## grant123

That was a crazy week.  I will get those line stats this coming week.

Filters are so cheap I think it's worth trying a new one.  Should it be better to get one that plugs into both the phone and modem like this:

https://www.amazon.com/In-line-DSL-Filter-w-Splitter/dp/B003807GK6

or one that only plugs into the phone?  This is for an office and there's only one phone.

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## NeddySeagoon

grant123,

The modem does not need a splitter.  The phone line is wired directly to to modem.

The way ADSL over the phone line works is the line is split into a number of 4kHz channels.

Baseband, 0-4kHz carries phone voice.

Then the are a couple of unused channels, so the filter does not need to be perfect.

Next are the ADSL uplink channels.

Above the uplink channels are the downlink channels.  How many downlink channels you can receive depends on lots of things.

Line length, noise ... the higher frequencies vanish first.

Test with only the modem connected.  All non modem devices need to be filtered somehow.

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