Altering ADSL line parameters with an Apple Mac

'Not sure if this is the best forum for this, but here goes.

I've been successfully using the ADSL utility 'DMT' on my Windows XP machine for some years now. The router I'm using is the Netgear DG834UK, the wired version, v.4. Within the gui of DMT, I'm able to alter the target SNR of my line so that the line runs stably. My line is around 3km in length and is frequently subject to large amounts of interference which, if left around the normal target SNR of 6dB, would bring my line down and endlessly cause resyncs. Being able to tweak the SNR to place it more like 12 - 14dB has worked fine over some years now, giving me a slower but at least far more stable connection.

Recently, I've been contemplating a change from my Windows machine to an Apple Mac machine. However, one of the basic truths is that (as far as I'm aware) there's no Mac version of DMT available from the mhilfe website. So, certainly any graphical means of changing my line's target SNR (and re-changing it on the eventual occasions when the line gets a huge whack of interference and resyncs back to the default 6dB) will be out of the question.

That said, I guess I can telnet into the DG834 instead and somehow alter the target SNR that way. I gather that telnetting on the Mac is quite straightforward to do in Mac OSX (Snow Leopard). However, I'm not at all sure if, once telnetted into the DG834 router, there'll be any command available with which to set the higher target SNR and thus cause the router to renegotiate the line. Does anyone know if there is? If so, do you happen to know the actual command? If this is possible, I can then from time to time just log into the router via the browser in the usual way, to check the down and up sync speeds, to see that all is well (or not, as the case may be).

Not sure how this lot applies if you are using a MAC, you can always ask on the MAC (Apple Issues) forum

This link shows you how to do it on the Broadcom chipped DG834GT.

There is a link to the forum as well.

Is your router Broadcom chipped?
You should be able to see what chip is in use with DMT, it's in the coloured information box on the bottom left of the web page once your connected with DMT, look for a set of numbers plus some letters after System Type, for example 96348GW-10

The number 6348 indicates the Broadcom chip in use.


EDIT > remember any changes are made at your own risk

Edited by Apprentice (Wed 21-Jul-10 15:25:41)

Another option would be to request your ISP to raise your Target SNR then you wouldn't need to tweak...

Yes, Apprentice, I've wondered whether to do that. But I somehow doubt that such a thing has ever crossed a Mac user's mind before. Nevertheless, I might give it a try. In my experience, Mac users simply don't think like us PC users.

Badger, I wouldn't want to keep troubling my ISP for that. With the SNR set by me at around 12 - 14dB, my line currently remains stable for (let's say) a couple of months, then invariably gets zapped by a level of interference that takes it over the threshold, and the line resyncs to some stupidly-high speed and thereafter keeps going down until such time that I fiorce the SNR up again. t'd be a right pain to have to get my ISP to intervene every time; they'd get totally fed up with me. I think they'd have to ask BT Wholesale, in turn, to effect the change anyway. It'd all take quite a bit of time, and what would I do in the meantime, anyway? At present, I can use DMT and get back to square one all within about 5 mins.

Re my DG834, yes, it's the 6348 Broadcom chip, as the no. is 96348W3.

Edited by deleted (Wed 21-Jul-10 17:44:40)

If you ask your ISP to raise your target SNR it will save you the problem of tweaking...

AIUI, you tweak your SNRM to ~12db, but eventually a resync occurs and it drops back to (at a guess) 6db, which is too low for your line to be stable. (edit- I know the feeling )

If your target is raised to 12db by your ISP it will stay at that value even after a resync. My line is OK with a 9db margin, and stays there regardless of occasional resyncs.

Edited by billford (Wed 21-Jul-10 17:49:47)

The instructions in the link given by Apprentice should work ok. Basically telnet to the router and issue the command

adslctl configure --snr x

where x = 50 for -3dB, 100 for no change, 150 for +3dB (relative to the default SNR margin).

To telnet the DG834v4, you first need to enable telnet access in the router by entering the following URL into a browser: http://192.168.0.1/setup.cgi?todo=debug

Telnet the router (telnet 192.160.0.1) (No idea how you do that in a Mac) and you should get the # prompt.

The command to tweak the SNR is: adslctl configure --snr n where 'n' is a percentage of the DSLAM target SNR.

Eg: adslctl configure --snr 50 would set a target SNR of 3 dB - assuming the DSLAM's target was set at 6 dB.

As others have pointed out, the DG834 will revert to the DSLAM setting when a re-sync occurs.

Another option would be to install the appropriate DGteam firmware which, I think, allows you to adjust the target SNR through the web gui and retains the setting through a re-sync.

John.

Billford,

Thanks for that. Are you sure about that? I certainly didn't realise that that was possible. Looks like I might have to give that some thought, then. I've often mentioned the matter to my ISP but they've never suggested that they themselves tailor it for me. Normally, they're very helpful.

Trouble is, I can't be too precise as to the figure for them to use, as the threshold is gradually changing with time, as more residents in my precinct get online (and therefore crosstalk in particular increases). I'm fairly sure the interference is caused by some semi-industrial place halfway to the exchange, so what's happening is that my line endures a median level of fairly constant electrical interference, then every so often gets a really high transient level that causes the line to drop out and the router resync. Sometimes 12dB seems adequate but on other occasions it takes 14dB to find a happy medium between stability and sync speed. When I first started out on ADSL Max some years back, my line would happily sync at around 4.4M bps but now it'll only be stable at 3.7M bps.

In reply to a post by meditator:

Badger, I wouldn't want to keep troubling my ISP for that.

Hi m3diator.
You don't need to keep 'troubling' your ISP - they can 'pin' you TSNR.

I remember you saying your are on good terms with your ISP 'engineers' so this will be easy for you to get put in place

I'm no expert but I think with the correct firmware you can also 'save' the TSNR tweak so that it remains between router reboots. This would mean you wouldn't need to keep tweaking things.

John,

It's not clear which figure you enter if you want to increase, rather than decrease, the SNR. The link on the KItz website gives some idea about the figure to insert but it doesn't consider anything above 9dB. Clearly, if my DG834 responds, I'll have to initially experiment with some figures.

I too have been wondering about DGTeam but it was my understanding that DGTeam was only Windows-compatible. Certainly, there seems to be nothing at the DGTeam website to indicate any relevance of the DGTeam software to Apple machines.