Kitz Forum

Broadband Related => ADSL Issues => Topic started by: adam25185 on October 11, 2011, 08:44:06 PM

Title: DG834G Target SNR Using Telnet
Post by: adam25185 on October 11, 2011, 08:44:06 PM
I have recently upgraded my modem to a Netgear DG834G and purchsed new ADSL Microfilter ADSL Nation XF-1e. As a result my ADSL no longer disconnects frequently, however there are still problems: the connection will sometimes grind to a halt for 20-30 seconds (without actually disconnecting).

Firstly, by checking, I believe this is associated with times with poor SNR Margin. Is this reasonable?

I would therefore like to adjust the SNR Margin target. I realise this will lead to a slightly slower connection, but I would be willing to lose a couple of megabits in order to achieve stability reliably.

I'm looking at the following page:

http://www.kitz.co.uk/routers/dg834GT_targetsnr.htm

I've tried to connect to the router using telnet (command used "telnet 192.168.0.1") however I get the message "Could not open connection to host, on port 23: Connect Failed".

Clearly in the forum, there are some people with the DG834G managing to use this procedure:

http://forum.kitz.co.uk/index.php?topic=5195.msg118218#msg118218

Can anyone see where I'm going wrong?
Title: Re: DG834G Target SNR Using Telnet
Post by: burakkucat on October 11, 2011, 09:59:10 PM
What version of DG834G do you possess, Adam?

I used to use a DG834Gv5 and it was perfectly simple to access it via telnet once it had been put into debug mode.

http://192.168.0.1/setup.cgi?todo=debug
Title: Re: DG834G Target SNR Using Telnet
Post by: roseway on October 11, 2011, 10:33:27 PM
You can't tweak the noise margin on the DG834Gv5. You need a v4 for that. Another good option is to get an ex-Sky DG834GT (if they're still available).
Title: Re: DG834G Target SNR Using Telnet
Post by: adam25185 on October 11, 2011, 10:55:03 PM
I changed the SNR Margin so it's now 12db, nevertheless it seems that these slowdowns for a few minutes to just a few kbps persist. I really have no idea what can be causing it?  :(

Is there any merit to changing my ISP, I'm currently with Demon?
Title: Re: DG834G Target SNR Using Telnet
Post by: burakkucat on October 11, 2011, 11:51:48 PM
You can't tweak the noise margin on the DG834Gv5.

I trust you didn't think I was implying that, Eric?  :no:

I was attempting to get the "full picture" from Adam, so that those with greater knowledge of the tweaking process could then "take over". It did seem to me, from my reading, that there initially was a problem in establishing a telnet connection to the device. ;)
Title: Re: DG834G Target SNR Using Telnet
Post by: sevenlayermuddle on October 12, 2011, 12:26:26 AM
I changed the SNR Margin so it's now 12db, nevertheless it seems that these slowdowns for a few minutes to just a few kbps persist. I really have no idea what can be causing it?  :(

Is there any merit to changing my ISP, I'm currently with Demon?

If throughput stops completely for a few moments and then recovers, then it may be a deficiency of your router, wiring or line, as the slowdown might coincide with a drop in connection and/or a burst of errors.   But if it simply slows to a few kbps, which lasts for some time,  it is more likely to be traffic management, or simple congestion, within your ISP.  In that case,  tweaking the target noise margin won't help  in the slightest.

You could install routerstats and monitor your line to try and prove it one way or the other, but the fact you are with demon makes me deeply suspicious.   Demon have long-since had a traffic shaping policy, they have also recently adopted a tactic of 'prioritising' business traffic.  In other words those who pay more get better throughput.  But there's only so much bandwidth in the melting pot so, in order to create the bandwidth to 'prioritise' business users, it would appear that they must be wilfully impeding traffic from other subscribers.  I am also with demon, and it is not at all unusual for throughput to drop to modem speeds (say, 50kbps) at busy times of day.

Personally, I am unable to escape from demon as many websites (some of which I care about) still link to my old ----demon.co.uk website, despite the fact I changed it to a non-demon ---.com address many years ago.  Similarly, people still send mail to my ----.demon.co.uk address. despite having long since got my own ----.com.  If it were not for that, I'd have dropped them like a hot potato years ago.  That is, of course, just my opinion.  :)
Title: Re: DG834G Target SNR Using Telnet
Post by: roseway on October 12, 2011, 07:11:58 AM
I trust you didn't think I was implying that, Eric?  :no:

Sorry, I misunderstood your comment. :)
Title: Re: DG834G Target SNR Using Telnet
Post by: adam25185 on October 12, 2011, 08:37:19 AM

You could install routerstats and monitor your line to try and prove it one way or the other, but the fact you are with demon makes me deeply suspicious.   Demon have long-since had a traffic shaping policy, they have also recently adopted a tactic of 'prioritising' business traffic.  In other words those who pay more get better throughput.  But there's only so much bandwidth in the melting pot so, in order to create the bandwidth to 'prioritise' business users, it would appear that they must be wilfully impeding traffic from other subscribers.  I am also with demon, and it is not at all unusual for throughput to drop to modem speeds (say, 50kbps) at busy times of day.



I will leave routerstats running today. I'm not quite sure how to expand the scale of the SNR Margin graph to show the entire day's statistics.

It does seem however that the router just slows down to virtually nothing rather than actually disconnecting. I mainly use it in the evening, so I don't know whether it can be business traffic at this time?

I'm looking at http://www.kitz.co.uk/isp/caps.htm and I don't see any traffic management for Demon?

What is a good ISP? Are Sky Broadband any good?
Title: Re: DG834G Target SNR Using Telnet
Post by: sevenlayermuddle on October 12, 2011, 09:28:31 AM
Quote
I'm looking at http://www.kitz.co.uk/isp/caps.htm and I don't see any traffic management for Demon?

One way to (quite spectacularly) expose demon's traffic shaping used to be the TBB speed tester.  That allows you to choose different TCP ports for the test.  If the two different ports give widely different throughputs, them the only explanation would appear to be traffic shaping.  See kitz's post in a thread on the subject from some time ago (shame kitz's link no longer works).

http://forum.kitz.co.uk/index.php/topic,4449.msg104923.html#msg104923

That said, I have just tried the TBB speed tester and no longer see evidence of traffic shaping.  That may mean they no longer do it, or it may just mean they are getting cleverer, so that it doesn't show up in the speed tests.  It may also be different later in the day, try it yourself when throughput is slow... run it once with default settings, then again with the port 80 box ticked.

http://www.thinkbroadband.com/speedtest.html

Whatever the explanation, I see exactly the same symptoms you describe on my own demon connection, occasional slow downs to pathetic throughputs.   The upgrade to 'business 2+' (with prioritised traffic)  doesn't cost that much more than the basic package.  It also gets UK support (not Indian) so I'd have gone for it, but unfortunately I don't have adsl2, and the only demon product that offers prioritisation of DSL Max is about twice the price.






Title: Re: DG834G Target SNR Using Telnet
Post by: adam25185 on October 12, 2011, 10:18:17 AM

Whatever the explanation, I see exactly the same symptoms you describe on my own demon connection, occasional slow downs to pathetic throughputs.   The upgrade to 'business 2+' (with prioritised traffic)  doesn't cost that much more than the basic package.  It also gets UK support (not Indian) so I'd have gone for it, but unfortunately I don't have adsl2, and the only demon product that offers prioritisation of DSL Max is about twice the price.

I'm looking at the page:

http://www.demon.net/broadband/business-broadband/demon-business-broadband-2

So do you know if this would prevent all slowdowns or just 'during busy times'? Is there a way to tell for definite that I have ADSL2+? On my bill have have ADSL 2+ so I assume I do?
Title: Re: DG834G Target SNR Using Telnet
Post by: sevenlayermuddle on October 12, 2011, 10:35:12 AM

Whatever the explanation, I see exactly the same symptoms you describe on my own demon connection, occasional slow downs to pathetic throughputs.   The upgrade to 'business 2+' (with prioritised traffic)  doesn't cost that much more than the basic package.  It also gets UK support (not Indian) so I'd have gone for it, but unfortunately I don't have adsl2, and the only demon product that offers prioritisation of DSL Max is about twice the price.

I'm looking at the page:

http://www.demon.net/broadband/business-broadband/demon-business-broadband-2

So do you know if this would prevent all slowdowns or just 'during busy times'? Is there a way to tell for definite that I have ADSL2+? On my bill have have ADSL 2+ so I assume I do?

I wouldn't like to speculate the degree of improvement you'd see from a prioritised business account, it'd be a case of suck it & see.  But when I discussed it with a sales rep, he did encourage me to think I'd see improvements (until we realised it wasn't available to me).  Note also that they'll likely offer shorter contracts for a small increase in premium, if you don't like the idea of 24 month ties (I don't).

Meanwhile, I'd carry on with RS plots to investigate whether your problems may be local.  Unfortunately I'm not a great user of RS, not installed anywhere at the moment, so not the best person to advise on that aspect.  I seem to recall you can configure it to take a series of snapshots through the day, and save away the screen images a nominated folder, but I don't know the details.  There may be other ways too.
Title: Re: DG834G Target SNR Using Telnet
Post by: jeffbb on October 12, 2011, 10:44:46 AM
Hi
your router stats should show your current package +all other useful information for troubleshooting .
http://www.kitz.co.uk/adsl/frogstats.php can you post your stats ?

quote I will leave routerstats running today. I'm not quite sure how to expand the scale of the SNR Margin graph to show the entire day's statistics.

in the configuration you can set up the sampling rate and the number of samples per page.
see the on line help or you can use the help provided with RS
http://www.vwlowen.co.uk/internet/routerstatshelp/routerstatshelp.htm
select configuring graphs ,on the second Common settings page you will see the points per page when you increase this the time per page increases ,there is a relationship between "points per page "and the "sample every" options so a little experiment watching the displayed time will allow you to display any amount of data per page .
Regards Jeff
Title: Re: DG834G Target SNR Using Telnet
Post by: sevenlayermuddle on October 12, 2011, 10:50:45 AM
@Jeff, thanks for helping re RS.   :)


PS: re demon business... 
If thinking about taking a demon business account, read the T&C carefully as there many differences between 'consumers' and 'business' users, including the all-important indemnity clause.  But I'm not sure whether opening a 'business' account would necessarily make you a business user, in so far as the contractual terms seem to relate to the activities of the user, rather than the name of the package.   Nor have I ascertained whether they actually ask for any evidence that you are running a business.

I did find the sales rep quite friendly and helpful, so don't be afraid to just call and chat to them...
Title: Re: DG834G Target SNR Using Telnet
Post by: adam25185 on October 12, 2011, 01:03:33 PM
I'll set up Routerstats when I get home and post the graph tomorrow. I'm pretty sure it's not related to the SNR as I said, since I have increased the SNR margin manually, and I was at 12db SNR margin last night when it couple of minutes of slow connection.

When I say slow connection I mean the broadband speed drops to only 50-300kbits/sec. This usually lasts a couple of minutes as I say.
Title: Re: DG834G Target SNR Using Telnet
Post by: jeffbb on October 12, 2011, 05:04:32 PM
Hi
quote I'm pretty sure it's not related to the SNR as I said, since I have increased the SNR margin manually,
You would NOT expect SNR margin to affect throughput unless it was so low that you were generating lots of CRCs (errors needing retransmissions ).
Can you post your Router stats ?
Regards jeff
Title: Re: DG834G Target SNR Using Telnet
Post by: burakkucat on October 12, 2011, 05:23:56 PM
I trust you didn't think I was implying that, Eric?  :no:

Sorry, I misunderstood your comment. :)

b*cat smiles and makes a note to ensure that he tries to be as precise as possible in all his future postings. :)
Title: Re: DG834G Target SNR Using Telnet
Post by: adam25185 on October 12, 2011, 08:49:38 PM
I have attached the two graphs for SNR Margin and Sync Speed. This is with the whole modem reset and the SNR Margin target at default. As you can see, there are no problems. I will run a longer scan tomorrow.

Cheers for your help.

[attachment deleted by admin]
Title: Re: DG834G Target SNR Using Telnet
Post by: jeffbb on October 12, 2011, 11:23:50 PM
Hi
Have you kept a record of the router stats including errors ?
Now that RS is running when you get the slw down in throughput you should see that your Synch rate does not change now even if the snr drops this should have no affect unless it causes a resync or as I said before creates too many CRCs . Have you selected to Graph the "RX crc/es/lof

Regards Jeff
Title: Re: DG834G Target SNR Using Telnet
Post by: adam25185 on October 13, 2011, 11:50:36 AM
Have you kept a record of the router stats including errors ?

I don't know where to find this? Do you mean the log? The log has a lot of features from me adjusting things where I have disconnected it.


Now that RS is running when you get the slw down in throughput you should see that your Synch rate does not change now even if the snr drops this should have no affect unless it causes a resync or as I said before creates too many CRCs .

I can't see anything at all shift in the router stats upon slowdown. I will check carefully next time I experience one.

Have you selected to Graph the "RX crc/es/lof

Regards Jeff

Can't see where to do this? In RS?

I will upload full 24-hour stats graphs when I return home. As I explained, they basically don't show anything.
Title: Re: DG834G Target SNR Using Telnet
Post by: sevenlayermuddle on October 13, 2011, 01:27:38 PM

I can't see anything at all shift in the router stats upon slowdown. I will check carefully next time I experience one.


That's pretty much what I expected, I saw no reason to think it was your router, or wiring, or lack of margin, that was at fault.  But I also didn't want to feel responsible for persuading you to switch ISPs, or to pay more to your current ISP for a better package, without first eliminating other causes :)

You could also take a look through the tweaking/MTU/RWIN guidance at http://www.kitz.co.uk/adsl/MTU2.htm , but I frankly think you're just experiencing ISP congestion and/or traffic management.

If I were in your shoes, given the analysis you've already done, I'd probably decide that the time had come to migrate to another ISP (or to a 'better' demon package).  I can't promise with 100% certainty it would improve things much, but I'd be willing to take the chance.  But that's your choice...  and who knows, there might be some aspect of your home setup that we've all overlooked?

One more thing occurs, though....  talking of things we might be overlooking, I've been assuming the problems you are experiencing are on a wired connection.  If you are using Wi-Fi then let us know, as that's a whole other kettle of fish that can have problems of its own.

Title: Re: DG834G Target SNR Using Telnet
Post by: adam25185 on October 13, 2011, 07:29:52 PM
I've attached nearly 24 hours of Routerstats graphs. These seem to show no loss of sync, which has been my experience since I upgraded my modem and filters (see page 1 of this thread). It should be noted that I've not experienced any slowdowns in this 24-hour period either (possibly as I have been at work all the time  >:().

I should now look at the SNR Margin when I experience a slowdown and see whether this drops to zero?

I will also try using an ethernet cable, although I've tried this before and it didn't seem to make any difference.

Please let me know your opinion of what I should do next.

[attachment deleted by admin]
Title: Re: DG834G Target SNR Using Telnet
Post by: sevenlayermuddle on October 13, 2011, 07:57:41 PM
Well, assuming wi-fi is not the problem, here's my thoughts, others may differ...

There was a bit of s step improvement in SNRM around about 7am, and a step back about 5pm, which is unusual... a gradual slope between day & night is more common.  If you could work out what caused that step, and if you could do anything about it, you might be able to maintain a slightly better connection speed.   But it's all a bit irrelevant as connection speed (correct me if I'm wrong) is not what's worrying you, it's the pauses and EXTREME go-slows in throughput.  I don't see anything to explain these problems, and therefor I'd attribute them to ISP congestion or traffic management.

As stated, I am also with demon, and I see pretty much the same symptoms that you describe.  All is generally OK but in recent months but, if I'm doing a lot of downloads as I am at the moment (experimenting with Linux builds), then every so often - say, several times an hour, things grind almost to a standstill for perhaps a minute or two. I can never prove whether the host websites or demon is the bottleneck, but demon is the common denominator.

It maybe worth noting that demon do have a usage allowance but it's quite generous and, unless you're in the habit of continuously downloading HD movies, I doubt that's the problem.  And anyway, a usage cap wouldn't show up as 'intermittent' slow downs.

Given the evidence you've obtained I'm inclined to suggest that demon is the problem.  You could complain to them, but they likely try and fob you off.  In any case, if their network is chronically congested then they probably already know about it and made a corporate decision not to care about it.   You could complain vigorously, and demand that they let you out of any remaining contract period, but they may of course refuse.   Realistically, your best bet may simply be to accept any extra cost, and switch to a different ISP.  But see my cautions in previous post, it has to be your own decision.

Or does anybody else think differently...?

- 7LM
Title: Re: DG834G Target SNR Using Telnet
Post by: adam25185 on October 13, 2011, 08:22:22 PM
I'm actually out of contract with Demon now, so that's not a problem. My only restriction is that I don't want more than a 12-month contract since I may not be living here after 12 months. I did a LLU search on samknows.com with the results in the jpeg. Please let me know what ISPs you think might be the best choice? I hear good things about Sky from my friend.

Some ISPs eg Andrews & Arnold seem to have very good ratings but are very expensive.

I also want an ISP without a traffic management policy for P2P applications (eg not Plusnet).

Thanks for your help again.

[attachment deleted by admin]
Title: Re: DG834G Target SNR Using Telnet
Post by: sevenlayermuddle on October 13, 2011, 10:03:37 PM
I'm actually out of contract with Demon now, so that's not a problem. My only restriction is that I don't want more than a 12-month contract since I may not be living here after 12 months. I did a LLU search on samknows.com with the results in the jpeg. Please let me know what ISPs you think might be the best choice? I hear good things about Sky from my friend.

Some ISPs eg Andrews & Arnold seem to have very good ratings but are very expensive.

I also want an ISP without a traffic management policy for P2P applications (eg not Plusnet).

Thanks for your help again.

Hopefully others will now join in and advise.  My only experience is with demon - who used to be very good indeed at the dawn of home internet 10-15 years ago, what a shame they've gone so far downhill (my opinion only, of course).   I'd be willing to give a demon business account a try if they'd let me, on the off-chance it might improve things, but things might not improve, it could just become a case of good money after bad, so not sure it's what you want.

So speak up kitz'ers, any ISP recommendations for Adam, based on his criteria...?
Title: Re: DG834G Target SNR Using Telnet
Post by: waltergmw on October 14, 2011, 09:34:05 AM
Expense is relative, especially if it costs you a lot of trouble !

AAISP are good with good fault investigation capabilities. So are Zen Internet and their standard (not FTTC) products on a month's contract still (I think). Zen has an excellent fault reporting and logging system with a UK call centre using skilled technicians.

Kind regards,
Walter
Title: Re: DG834G Target SNR Using Telnet
Post by: roseway on October 14, 2011, 10:01:36 AM
I think I'm with Walter here - to a large extent you do get what you pay for. However you generally get more for your money from LLU operators, and of the ones available to adam25185, Sky is probably the best option (although I don't have any personal experience of any of them).