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[malcolm101]

Hi All can anyone help i have been using an alcatel internal dsl modem and the speeds i recieved have been variable on a good day i could sync at 1856kbps and bandwidth 1.45 mbps.Now i want to use my dg wireless router i have installed it and all i can achieve is sync at 160kbps bandwidth
78kbps . Have set up router stats which tells me  rx sync 160kbps rx noise 12.3 db. But on noise margin graph db varies from 7 to 21 does anyone
have any suggestions please you guy's know what your doing i don't. And attenuation is 60 db

[kitz]

7 - 21dB fluctuation isnt good

The dg834gt is normally a pretty decent router, so I wouldnt have expected it to perform so much worse than the internal modem.
Is the router in the same general area as the PC in what contained the internal modem?   Have you tired connecting in the test socket to see if there any improvement?
The huge fluctuation is perhaps indicative that there is some sort of noise being picked up on the line..  Is there anything near the router which could be causing this eg CRT monitor etc.

[malcolm101]

Hi Kitz thanks for answering i am not very clued up on this ,does the dg suffer from interference
it is nowhere near any thing like that',could the internal modem be reporting wrong.also i checked
on btw speed test and my ip profile is 135kbps what i can't understand is why my sync speed is so low
could the router be reconfiguring the connection if so how long should it take to settle thanks

[kitz]

>> does the dg suffer from interference

No, its one of the better ones,  I just wondered if it was perhaps picking up some sort of interference from an external source.

>> could the internal modem be reporting wrong

highly unlikey - not when yours speeds are also so low

>> my ip profile is 135kbps

Obviously due to the very low sync speed

>> ould the router be reconfiguring the connection

No, the router and DSLAM at the exchange will always negotiate the best speed it can.  Lower sync speed is a result of a reduction in signal strength compared to the noise on the line (SNR = Signal to Noise Ratio).

The large fluctuation in SNR Margin is indicative to "noise" being introduced somewhere on the line. Have you made sure the filters are installed correctly?  Where is the router located is it near equipment that could be emitting electromagnetic noise?

The first thing I'd try is plugging the router into the test socket behind the master socket to see if things are ok from there - link.

[malcolm101]

Hi thanks for reply have now tried most of the suggestions and have played with dgteam software
and have come to the conclusion that at 60db attenuation the router is not a good idea best i had lowering
% snrm was 1300kbps but router disconnected and re synced at 340kbps.thanks for trying to help
One last question my internal modem syncs at 2350 using t1 mod and 1400 using g-dmt which is isp setting
will this cause other problems thanks

[kitz]

>> at 60db attenuation the router is not a good idea

That is very strange as (certain) routers are normally much more stable, so its interesting to see that a pci-modem seems much better at attaining sync.

Ive not personally encountered a pci adsl modem, and they arent very common these days, and iirc were mostly used around the period 2002/2003ish when BT brought in the "self install".  With having a network Ive always personally opted for a router - even back then-  and any installs Ive done for others have either been router or ISP supplied usb modem.
I dont think I know anyone who has a pci adsl modem, and in view of their rarity these days, its therefore interesting to see your observations on how they perform on your own line.... since they kinda went out of "common usage"  before the higher 1Mb/2Mb speeds and max dsl was brought in.

In view of the performance on your own line, I can well understand why you'd look at continuing to use the pci modem.
It may be interesting though, to see if you have a friend with a router who wouldnt mind swapping out routers for a couple of days, just to ensure that it wasnt that particular router.

>> One last question my internal modem syncs at 2350 using t1 mod and 1400 using g-dmt which is isp setting will this cause other problems thanks

This gets stranger and stranger..   adsl uses g.dmt modulation.  T1 modulation is completely different and a maximum of around 1.5 Mb.

oooh stop...  just had a thought...  wonder if thats actually ANSI T1.413 modulation. 
I dont actually know that much about ANSI T1.413 modulation aside from some basic investigation that I made into it about a year ago under what is known as S=1/2 mode.
S=1/2 mode is the sole reason why some routers will sync at more than 7616 despite being interleaved.  I only looked into it on the basis of how it treated interleaving for that page...  but iirc it combines 2 code words into one larger code word, and effectively increases maximum speed up to around 15Mbps. 
Both the router/modem and DSLAM need to be able to support this mode.  I'm not going to blindly tell you about something I dont know much about..  but..  having just had a look at who your ISP is, and the fact that they use LLU  MSANs that are capable of adsl2 speeds, but throttle it back at a user level..  it could well be the reason why you can get higher speeds using this type of modulation.  Sorry I cant give you any more info, aside from some routers (including some Netgears) can use S=1/2mode.

[malcolm101]

Hi Kitz thanks for reply i know i said last question but if you don't mind i don't like giving up would you take a look at this dmt page to see if anything jumps out at you .I did as you suggested and tried another dg834gt still the same then set mine on friends line all ok .have sent graph from routerstats
and yes it is ansi

[attachment deleted by admin]

[kitz]

Hi

I dont see anything on the DMT info other than a sync rate of 192 is extremely low for a 60dB line and the signal quality is very low.

The routerstats graph isnt very good, the fluctuation of between 3dB and 22dB and its very spikey.  which is highly indicative of interference from somewhere.

I'm not sure what to suggest since you say all is well if you use the PCI modem.  If it wasnt for that, the fact that you'd tried both the master socket and another router with the same result, then normally I would recommend that it needs investigation by a BT engineer as a possible fault on the line.  You could contact your ISP and could make out that your line has suddenly deteriorated.. because the current sync is below what it should be.   The only thing I'm scared of is that if an engineer comes and plugs his modem into the master socket and is able to get a decent sync, then you could end up with a £150 bill.

Have you tried the quiet line test to see if you can hear any noise on the actual line?
(Dial 17070 and select option 2.)


----
Ezzer, (or anyone else) if youre about, your opinion on this would be appreciated as to how you would deal with this from an engineers PoV.
- The line should in theory be able to attain a much higher sync than this with a router, but its stable with the PCI modem, have you come across anything like this before?

[malcolm101]

Hi Kitz i am back on internal modem here are the stats
upstream 448
downstream 2432
fec 5740
crc 56
atm hex 41
tried this morning the am radio test got a reading from pc and lcd monitor so moved the router as far as e cable would let me no difference have tried all available firmware no difference one thing about internal modem is throughput does vary .Also using dgteam software to alter snrm does get sync up but disconnects frequently

[roseway]

I wonder if this is a high resistance line fault, and the reason the PCI modem works better is simply that it loads the line more (or possibly less) than the router.

[malcolm101]

Hi thanks for input presumably because internal modem seems stable it must be more tolerant of the line although as i said throughput does vary .
I suppose next thing is try isp but in the past not been very helpfull.

[kitz]

>> I wonder if this is a high resistance line fault, and the reason the PCI modem works better is simply that it loads the line more (or possibly less) than the router.

Thanks eric ... I honestly dont know, it very well could be.   Obviously theres something wrong somewhere that the PCI modem has been able to mask.
The reason I suggested the Quiet Line test was to check to see if theres any indication of a HR fault.


>> one thing about internal modem is throughput does vary

ahh.. so there is some fluctuation with the internal modem too.

Did you try the quiet line test to see if your can hear anything? You can often hear crackling/noise on the line if it is a high open fault.


>> I suppose next thing is try isp but in the past not been very helpfull

Unfortunately, your ISP is one of those that it can be a battle with to get them to call out a BT engineer and you will have to insist that you speak to 2nd/3rd line support. 
FYI the sync figure of 135kbps is unacceptable for a 60dB line and even on lines much longer then BT will attempt to get a sync of at least 256kbps.

You may have to bite the bullet and keep the router plugged in giving you the rubbish speeds for tisali to accept that theres a fault.
Whilst not strictly ethical, but in view of what their CS is like.. if it was me I think I would be tempted to keep the router plugged in and report that the line suddenly appears to have developed a fault causing very low sync speeds.  Tell them that youve already tried the master socket and have also borrowed another router just to check that its not your own router thats at fault.
As soon as they hear that your PCI modem is ok, they will say its a router issue and then you will have a hard time trying to take it further.   

[malcolm101]

Hi have tried the test you suggested nothing on line yes the internal modem does vary but only i would say at peak times it is still syncing at 2.4 will try isp and see what they say thanks for your help strange one this.

[kitz]

Good luck

[malcolm101]

Hi sorry to be a pain but before i have a go at isp does the graph from routerstats now point to a line fault thanks