Kitz Forum
Broadband Related => ADSL Issues => Topic started by: silversurfer44 on June 08, 2009, 02:20:38 PM
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Please forgive me if this is in the wrong section. I have been trying to download the DMT application from the website, however when I go to the site all I get is a blank page. No errors or page not found. Can anyone else reach the page please?
Thank You.
This is the site I've been using http://dmt.mhilfe.de/
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Same for me, I'm afraid.... :(
However, if you go to this page on Kitz http://www.kitz.co.uk/routers/DMTv7.htm , and go down to the section which explains that the page/product is German, you will see the link "translate the page"..............click on that and it takes you to http://translate.google.com/translate?hl=en&sl=de&u=http://dmt.mhilfe.de/&sa=X&oi=translate&resnum=4&ct=result&prev=/search%3Fq%3Ddsl%2Bmodem%2Btool%26hl%3Den%26lr%3D%26rlz%3D1B2GGGL_enGB177
Once there, look at the FAQ list on the left, scroll down through that and you will find a downlood link for the tool.
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Give this link a try:-
http://translate.google.com/translate?hl=en&sl=de&u=http://dmt.mhilfe.de/
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Many thanks. I looked at that very page but gave up before looking down the links. A Very senior moment. ;)
Thank you again.
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:thumbs:
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Seems to work OK for me.
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>:( Well I installed V7 which will connect to my Thompson O2 router, however the firmware is not supported.
As I run a linux OS I also tried the Unix version but had many difficulties in compiling that I gave up. So I thought I would try the Windows way using the vbox emulator alas as stated above the firmware is not supported. Back to routerstats-lite. Thumbs up a bit premature. Thank you any way.
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Hi Silversurfer,
Have you remembered to tick the box allowing untested software ?
Kind regards,
Walter
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I'm not sure which box you're meaning there Walter. I have on near the top on the dmt interface that says 'get Versions info' I guess that could be the one. I cleared the tick and lo & bold it works. The only thing is I have to delete the config file and start again everytime I start the app. No real problem. Now I have to learn how to interpret it all now. Happy days. With all the information from around this wonderful site I will get there.
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>> Now I have to learn how to interpret it all
It can take a while, unfortunately DMTtool is read only with the TG585v7 but it can still give out some pretty useful info.
Theres a page on the main site which explains DMT modulation (http://www.kitz.co.uk/adsl/adsl_technology.htm) which should hopefully explain some of the info that DMT tool gives.
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Well time is what I have a lot of at the moment. ;D I have read the page you refer to Kitz (a number of times) and I'm still getting my head round it.
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>> and I'm still getting my head round it
a bit of light bed-time reading eh?
DMTZzzzzzzzzzzzzzzzzzzz
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Hi Silversurfer,
Have you remembered to tick the box allowing untested software ?
Kind regards,
Walter
:thumbs:
After some searching I found the box you mentioned.
It sort of does the job. The middle graph is not plotting but I think the main details I wanted are showing.
Yes Kitz I have had some Zzz's, you are supposed to make it sing you know. ;D
First screenshot attached.
[attachment deleted by admin]
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I cant really see anything obvious from that and all seems to look ok.
The bit-loading graph is actually looking quite normalish for a 50dB line
Theres a few bins that perhaps could load more bits... but theres nothing specific across the frequencies that shows real problems.
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Thank you Kitz for looking over the snapshot, as you may have noticed that was taken just after rebooting the modem. I have now included one after an overnight run. Quite a difference I think.
One query I have is :-
According to the display I have an ADSL2+ connection, yet the package I have been given by O2 is a 12meg connection, according to the information on the page you directed me to 12meg belongs on an ADSL1&2
Quote 'ADSL(1&2) has a maximum available 223 downstream subchannels. 223 x 56kbps = 12Mbps.' ???
I am not over bothered about this it just confuses me a little.
The next thing is that when I signed up with O2, after great difficulties with my former isp (who shall remain nameless), BTW informed my new isp that I could expect a 7meg connection. I know this was optimistic, and acknowledged by the O2 team, however, they were a little disappointed by the 4.5 meg connection and sent me an email on the matter, that was a nice touch.
Finally if someone will be so kind as to cast a knowledgeable eye over the screenshot I will be ever so grateful.
Thank you.
Maybe I should start a new thread for this as I think it may run a bit?
[attachment deleted by admin]
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There's nothing particularly unusual in that graph. You have a highish attenuation, and it's inevitable that some bitswapping will take place to maintain the integrity of the connection.
Although your package is described as 'up to 12 Mbps' it will still be ADSL2+ but capped to 12 Mbps by the ISP.
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Thank you again Eric. I understand more now. I was a bit concerned about the gaps that appeared in less than 24 hours.
Ha well I'll just have to move house. :lol:
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>> Ha well I'll just have to move house.
Unfortunately that's sometimes the only way to get a better internet connection. :)
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>> According to the display I have an ADSL2+ connection, yet the package I have been given by O2 is a 12meg connection
adsl2+ is rate adaptive and your line will sync as high as it can up to 24Mb. The longer the line then the more the sync speed will reduce and its only the shortest lines that are able to sync at the full 24Mb.
Its possible to have a long line syncing at 2Mb that could be on adsl2+, since this is the specification of the technology used and the limitation of the line length.
>> 'ADSL(1&2) has a maximum available 223 downstream subchannels. 223 x 56kbps = 12Mbps.' Huh?
>> I am not over bothered about this it just confuses me a little.
adsl1 and adsl2 has sufficient channels for a line to theoretically sync downstream at up to 12 Mb. However overheads needed for such things as Error Correction and limitations of ATM packet sizes mean that there is a physical limitation of 8Mb set on the line at the dslam.
Theres something called S=1/2 mode which makes the Error Correction more efficient and switching to S=1/2 mode on adsl1 will allow a higher sync. S=1/2 mode combines 2 RS codewords into one making Error correction more efficient with regards to overheads.
Both the router and the dslam have to be able to cope with s=1/2 mode though for this to work... and its the reason why some interleaved lines will sync higher than the 7616 often quoted. However the 8128 is then a restriction set on the dslam which is why it wont sync higher than this for adsl1.
adsl 2 & adsl2+ already make use of s=1/2mode so no point fiddling with that any further if you are already using adsl2 or 2+
Just found this (http://www.iol.unh.edu/services/testing/dsl/training/ADSL_Tutorial.pdf) which explains S=1/2 mode a bit more.
Although in that article it says by using this it yeild up to a maximum 16Mbps for adsl2. Therefore Im not 100% certain why adsl2 is still set at 12Mb.. its very likely they are talking about the ideal world situation and no problems with crosstalk and no neighbouring lines to contend with.
Because of crosstalk certain channels cant be used for downstream.. so when that article refers to 16Mb it could mean total speed.. because adsl2 allows 12Mb downstream and 3.5Mb upstream on the channel allocation. Add those together and also add in the bands that cant be used (the stop bands and for POTs) then you are looking at 16Mb.
In the UK (and other countries) certain bands just simply cant be used for downstream and masks are applied to ensure that they arent used... or else anyone with a strong downstream signal at those frequencies would simply drown out any neighbouring upstream signals and vice versa.
I believe a very simplified way to look at this is
adsl(1) allows up to 8Mb downstream sync
adsl 2 uses S=1/2 mode to increase the downstream sync to 12Mb
adsl 2+ doubles the available frequencies allowing a maximum downstream sync of up to 24Mb
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Strangely enough I am beginning to understand quite a lot of what you are saying about adsl in general. I am also understanding what I am looking at in the graphs. Do I get a degree at the end of this please? :no:
Just one more question and that is is it a good idea to reboot these modems every couple of days or so? I know I don't have to worry about IP Profiles, but, am I likely to upset the dslam or something by doing this? The reason I ask is whilst the sync rate stays the same the throughput does degrade over time.
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>> is it a good idea to reboot these modems every couple of days or so?
I normally recommend you leave the modem/router to settle at its own level, only rebooting if you have a low or bad sync for some reason.
There may be times after a bad noise incident where the router can mark certain channels as unusable, which in turn can cause bit swapping perhaps not to be as efficient as it could be.. and in these cases it does no harm to do a resync or power-cycle.
The main thing is not to do it too often particularly if you are on a BTw based product or it may trick the DLM into thinking you have a more serious problem. Resyncing every few days though should be fine.
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Thank you for the advice yet again. I am now on a LLU based product which is why I said that I'm not worried with ip profiles now. I understand about not re-syncing for the sake of it and not too often, I was thinking a couple or three days in between. I asked the question as I noticed in the graph that quite a few more gaps had appeared, however I will let it run and see what happens. :fingers:
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I normally recommend you leave the modem/router to settle at its own level, only rebooting if you have a low or bad sync for some reason.
I have learnt from this :)
Leave you router as it is and "let it do its thing" !
Yes with LLU there are no LLU profiles to worry about.