Kitz Forum
Broadband Related => FTTC and FTTP Issues => Topic started by: broadstairs on April 11, 2018, 02:11:34 PM
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For a day or so now my SNRM has been varying between 5.1 and 6.1 down over a period of about 5 minutes, the graph almost looks like a sine wave, the up SNRM is varying in sync but only between 5.6 and 6.6 over. My CRCs are zero as are the ES and SES, FECs are between 0 and around 30 per minute with the odd spike up to a 100 or so but not for the past 20 minutes.
Any suggestions as to why the SNRM might be varying like this?
Stuart
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Oscillations can start after a disturbance in power. Powering down the modem for a short while can often clear it.
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Oscillations can start after a disturbance in power. Powering down the modem for a short while can often clear it.
Note sure I've had any power issues, at least none which have actually powered anything off/on although I did have a strange happening the other night when I got a couple of router disconnects in the early hours of the morning while every one was asleep. I do have a PC which runs 24x7 but it has not reported a reboot. I'll try that later on when the router is not needed and see what happens.
Stuart
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I got a couple of router disconnects in the early hours of the morning while every one was asleep.
A remote resync (by the dslam) is one of the things that frequently triggers oscillations on my line. It's a PITA, if MDWS was still up, I could point you to lots of instances of this happening. A power cycle of the modem usually fixes it.
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When N*Star first noticed it happening with his circuit (which terminates on a Huawei DSLAM) I suggested that, at the end of the day, he powered down the modem, over night, until the service was needed the next day. That certainly cleared the oscillations.
To the best of my knowledge no one has made a study of just how long a CPE needs to be powered down.
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I can manage a 30 minute outage without affecting much but my weather station runs 24x7 updating my website and several things happen overnight with daily uploads which will be missed if I turn it off overnight. I'll try the 30 minute thing and see what happens.
Stuart
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When N*Star first noticed it happening with his circuit (which terminates on a Huawei DSLAM) I suggested that, at the end of the day, he powered down the modem, over night, until the service was needed the next day. That certainly cleared the oscillations.
To the best of my knowledge no one has made a study of just how long a CPE needs to be powered down.
It's not DSLAM related. It's been happening since rate adaptive dsl (maxdsl) was rolled out. I would often see it happen on my Voyager 2100 after a powercut or even unexpected resync of the modem from the dslam end.
It was probably lesser known in those days because it was prior to the likes of DSLstats and even routerstats. I was only aware of it because back then I used MRTG (which was a pig to set up) to monitor my line. Anyone who isn't monitoring would never know. 9/10 it will clear after a power cycle. In fact when on adsl it would always clear after a full power down. FTTC seems a bit harder to shift sometimes and requires a few hours.. which I find more difficult as I tend to stream a lot these days and frequently go to bed to watch a movie or something on i-player in the hope it will make me fall asleep. The last thing I want to do is get up again and power down the modem.
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It's not DSLAM related.
Agreed. :) That is why I mentioned the manufacturer of the DSLAM to which N*Star's circuit is terminated . . . to show that it is not just ECI manufactured equipment, as I know that is to which b*stairs' circuit is terminated.
b*cat was obviously too subtle . . . ;)
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Well I have just (10 minutes ago) turned my router back on after 30 minutes and so far the SNRM both up and down seems to be a solid 6.5 at present. Looking at the SNRM per Band I see that my U0 band has jumped up to around 10 with the U1 &U2 being around 6.3, in fat I notice something like this quite often with the U0 being much higher than the other two.
Stuart