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[kit77]

Hi there, new to the forum and seeking some advice before splashing out £60-£100 on a new adsl router.

I have recently been moved by tiscali onto TalkTalk 8meg package. I think this move initiated a 10 day stabilization period which has now finished.

I am getting a much improved daytime sync speed of around 5151kbps downstream and 448kbps upstream. During the day the SNR fluctuates between 13.5 and 14.5 dB.

Come evening and street lighting on time the internet slows up and eventually throughput stops. During this time the SNR jiggers up and down by about 0.5dB before I have to force a reboot to get an internet connection. The downstream sync speed then seems to go down to about 4500 - 4700 kbps with new SNR around 15.5dB. Seems to stay stable and then a reboot in the morning gets me back up to above 5000kbps and the SNR back down a bit.

I have a D-link router DSL - G624M which is about 4-5 years old. It works in everyother way. It is connected to the master socket and the bell/ring wire has been removed from extensions. I have microfilters correctly installed and no noise on the voice line. My line attenuation is 36.5dB and I am about 2km from the exchange.

Given all the above I have 2 questions really:

1. given the line attenuation should I expect a higher sync rate and lower SNR?
2. if the above rings true would a new modem/router make the connection more stable and thus allow me to ask the ISP to try a lower SNRM profile?

when I asked the friendly tiscali/talktalk customer services advisor she kindly told me to be happy with what I have and that she could do nothing from her end. The talktalk forum is down for new registration so I cannot join to ask them there 

Thanks for any help/advice

Kit

Your help is much appreciated.

 router stats


DriverVersion                                      = 1.62
APIVersion                                         = GS_API_558
FirmwareVersion                                    = E.67.5.12     
DspVersion                                         = 0x000000c1
Connected                                          = true
OperationalMode                                    = G.Dmt
State                                              = Showtime
Watchdog                                           = 0x00000053
OperationProgress                                  = 0x000000ad
LastFailed                                         = 0x00000000
TxBitRate                                          = 448000
RxBitRate                                          = 5152000
RxATTNDR                                           = 0
CodeTypeStatus                                     = AnnexA
TxCellRate                                         = 1056
RxCellRate                                         = 12150
PhyTXCellCount                                     = 85138
PhyRXCellCount                                     = 493843
PhyCellDropCount                                   = 0
OverallFailure                                     = 0
INPup                                              = 0.0
INPdown                                            = 0.0
PMmode                                             = L2L3Allowed
PMstatus                                           = L0
SHalf                                              = Disable
CabinetMode                                        = Disable
AutoSRA                                            = Disable
AutoSRAMaxTimeCRC                                  = 0
AutoSRAMaxTimeFEC                                  = 0
AutoSRAUpShiftPeriod                               = 0
AutoSRADnShiftPeriod                               = 0
DataBoost                                          = Disable
LocalITUCountryCode                                = 0x0000b5ff
LocalSEF                                           = 0
LocalEndLOS                                        = 0
LocalSNRMargin                                     = 13.5 dB
LocalLineAttn                                      = 36.5 dB
RawAttn                                            = 36.5 dB
LocalTxPower                                       = 12.3 dB
LocalFastChannelRxRate                             = 0
LocalFastChannelTxRate                             = 0
LocalFastChannelFEC                                = 0
LocalFastChannelCRC                                = 0
LocalFastChannelHEC                                = 0
LocalFastChannelNCD                                = 0
LocalFastChannelOCD                                = 0
LocalInterleavedChannelRxRate                      = 5152000
LocalInterleavedChannelTxRate                      = 448000
LocalInterleavedChannelFEC                         = 99
LocalInterleavedChannelCRC                         = 5
LocalInterleavedChannelHEC                         = 3
LocalInterleavedChannelNCD                         = 0
LocalInterleavedChannelOCD                         = 0
RemoteTxPower                                      = 19.1 dB
RemoteSEF                                          = 0
RemoteLOS                                          = 0
RemoteLineAttn                                     = 17.0 dB
RemoteSNRMargin                                    = 24 dB
RemoteFastChannelFEC                               = 0
RemoteFastChannelCRC                               = 0
RemoteFastChannelHEC                               = 0
RemoteFastChannelNCD                               = 0
RemoteInterleavedChannelFEC                        = 0
RemoteInterleavedChannelCRC                        = 0
RemoteInterleavedChannelHEC                        = 0
RemoteInterleavedChannelNCD                        = 0
LocalMgmtFEC0                                      = 0
LocalMgmtCRC0                                      = 0
LocalMgmtFECErroredSec                             = 0
LocalMgmtErroredSec                                = 0
LocalMgmtSeverelyErroredSec                        = 0
LocalMgmtLOSErroredSec                             = 0
LocalMgmtUnavailErroredSec                         = 0
LocalMgmtHEC0                                      = 0
RemoteMgmtFEC0                                     = 0
RemoteMgmtCRC0                                     = 0
RemoteMgmtFECErroredSec                            = 0
RemoteMgmtErroredSec                               = 0
RemoteMgmtSeverelyErroredSec                       = 0
RemoteMgmtLOSErroredSec                            = 0
RemoteMgmtUnavailErroredSec                        = 0
RemoteMgmtHEC0                                     = 0
LocalTPSTCCell0                                    = 0
LocalTPSTCCell0UpperLayer                          = 0
LocalTPSTCBitError                                 = 0
RemoteTPSTCCell0                                   = 0
RemoteTPSTCCell0UpperLayer                         = 0
RemoteTPSTCBitError                                = 0
PSDMask                                            = NonOvlp-M1
ActivateLine                                       = None
HostControl                                        = Enable
AutoStart                                          = true
failsafe                                           = false
ShowtimeLed                                        = 2
Whip                                               = Disable
WhipActive                                         = Inactive
StatusFailCount                                    = 0
Action                                             = Startup
Profile                                            = MAIN
ProfileStatus                                      = MAIN
Standard                                           = G.Dmt.BisPlusAuto
UtopiaInterface                                    = Level1
EcFdmMode                                          = EC
MaxBitsPerBin                                      = 15
TxStartBin                                         = 6
TxEndBin                                           = 31
RxStartBin                                         = 6
RxEndBin                                           = 511
RxAutoBinAdjust                                    = Disable
TxAttenuation                                      = Bis_0DB
BitSwap                                            = Enable
BitSwapUp                                          = Enable
NTRMode                                            = Disable
CodeType                                           = ADSL2A
MaxDownRate                                        = 511
PhysicalPort                                       = 0
Retrain                                            = EnableOverallOnly
DetectNoise                                        = Disable
Capability                                         = BIS+/BIS/A/MULTIMODE
CodingGain                                         = auto
FramerType                                         = Type3ET
FastRetrain                                        = Enable
ClockType                                          = Oscillator
DyingGasp                                          = Disable
Defaults                                           = None
HappyMode                                          = Enable
resetDefaults                                      = false
portSnmpIfIndex                                    = 1
portSnmpIfType                                     = 37

[roseway]

It appears from your description that your target noise margin has been increased, probably to 15 dB. This would partly (but not entirely) explain why your connection speed is lower than it might be - you ought to be able to get a connection speed of over 7000 kbps. The probable reason is that your connection has been unstable and the target margin has been increased to stabilise it. To help diagnose this, it would be helpful if you could install Routerstats-lite which is compatible with your router, and use it to monitor the noise margin over time. This should show up any noise spikes or other interference effects which might be the root cause of the problem.

Another quick check which is worth doing is to dial 17070 and select option 2 for a quiet line test. If there is any audible crackling or hissing there may be a line fault.

[kit77]

thank you for your very speedy reply...

how long should I monitor the connection continuously for, bearing in mind that I have to reboot the router when the connection slows/drops off in the evenings?

[jeffbb]

Hi
quote how long should I monitor the connection continuously for, bearing in mind that I have to reboot the router when the connection slows/drops off in the evenings?

For as long as possible to see what is going on.

quote bearing in mind that I have to reboot

Why do you reboot ? too many of them may have caused your increase in the Target SNR. If the connection drops does it not reconnect itself?.

The slowing down is probably caused by contention.

Regards Jeff

[kit77]

When the connection has dropped and reconnected several times the internet through put slows right down and eventually I cannot reach the internet. It is at this time that I reboot to start using the internet again. Should I just see if it resets without doing so? it hasn't managed to get back up to speed before without reboot but I see why you might suggest I avoid doing so. I guess the bt end sees this as a disconnection and the reboot at lower sync higher snr is keeping the snrm profile high.

[Azzaka]

When the connection has dropped and reconnected several times the internet through put slows right down and eventually I cannot reach the internet. It is at this time that I reboot to start using the internet again. ...

That would be the modems NAT tables filling up. Turn of UPNP (Universal Plug and Play) and then see how it goes. Still no change the Borrow a modem and monitor the line for a couple days before buying a new modem.

[kit77]

will give it a try.

have managed to register with the talktalk forum and will see if they can do anything from that end too.

[kit77]

are these normal router stat graphs for the noise and drop offs?



[attachment deleted by admin]

[orainsear]

There are several rapid drops of the SNR margin to 0 dB.  This looks either like a data reporting error, or the synchronisation is dropping.

Have you noticed if your modem has been losing sync?

[roseway]

(Orainsear posted first, but I'll post this anyway.)

Not normal, no. Can you confirm that the connection actually dropped when those spikes occurred? The reason I ask is that with some routers Routerstats is sometimes unable to get a sample from the router because the router is busy with something else at the time. When this happens, Routerstats displays zero values just like your graphs above. I think this may be what's happening, because the spikes are so short-lived.

[kit77]

i haven't been able to confirm a connection drop at those times as that would be watching the routers onboard pages and waiting for a drop...

if it does happen then it reconnects very fast so it may well be more likely to be the routerstats software.

is the zigzagging of the snr signal normal?

*** okay just saw a dropping spike and no disconnect or drop off on the router page*** therefore must be routerstats?

I've disabled uPNP last night but still got to the stage where I had to reboot router to use the internet. is this still likely to be a NAT problem or could it be contention or just the very cold nights we've been having?

I'll borrow the old man's netgear router at the weekend and see if that makes a difference.

[jeffbb]

Hi
at least one of the drops resulted in 2 small step up  changes to the SNR margin and a bit late a small step down . This would normally  indicate a lost connection . I know that you do get steps in snr  margin with out disconnecting but it seems a bit coincidental . Have you managed to correlate the Synch graph and SNR graph to see how they relate , this migth help .
Does your router log give you any info on lost connections. I notice that some of the spikes are in red , that I believe may be occasions when the sampling has failed .

Regards Jeff

[jid]

I had a similar problem with throughput randomly dissapearing.

This was being caused by the build up of CRC errors. When this happens next, post up your stats again before you reboot so we can take a look. If this is the case then there could be a noise issue on your line.

I used to have the D Link DSL-G624T which is a similar model to yours and it did used to report SNR right down to 0dB, it could be a noise issue.

As many will know on this forum, after changing my router to a different one with a better chipset, all returned to normality with my connection and noise was managed more reasonable.

First give posting stats when your throughput goes a try first before we can consider your router the cause 

And welcome to the forums 

[b4dger]

As many will know on this forum, after changing my router to a different one with a better chipset, all returned to normality with my connection and noise was managed more reasonable.

I agree router choice can make a massive difference!

jid - any chance of telling those of us that aren't up to speed what router you changed to??? 

[kit77]

The SNR graph from 2128 on the 1st was an example of when I needed to force a reboot to get the throughput going again. I had paused the routerstats program otherwise it gives an exception error whilst rebooting.

I have attached it again and put the sync graph on also.

It did note that the crc , fec, and hec levels had gone into the tens of thousands at the time, typically happening every night.

incidently the router will not vary the sync speed unless rebooted so I guess it might not be actually disconnecting the connection with the DSLAM when it dips.

[attachment deleted by admin]