Kitz Forum
Broadband Related => FTTC and FTTP Issues => Topic started by: NewtronStar on September 29, 2019, 08:48:59 PM
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Hopefully this is in the right place, recently when I make a call on the the land line the SNRm will drop suddenly and when I hang up it recovers with CRC & ES as symptoms.
Will this be a Phone or Broadband issue that needs looking into by Openreach if this keeps happening ?
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Have used the ringback facility 17070 and this does not change or effect the SNRm it only happens during a phone call out as seen in my last 17070 quiet line test graph for a few minutes.
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What you have described appears to be the classic manifestation of the start of a HR or semi-conductive joint. Do you hear any noises when performing the quiet line test?
In terms of making a fault report, as it is a problem with the physical infrastructure -- the metallic pathway, it should be reported as a telephony fault. But before attempting to make a report, have you tested with a different telephone? Would a neighbour be willing to lend you their telephone, just for a quick 5 or 10 minutes?
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Cheers BC the quiet line test is very quiet indeed when using the BT4600 Dect handset which is only five months old don't have a corded phone at the moment.
Just made another call on the landline this morning and the VDSL link went down with ES and changes to line stats like sync and SNR lost the 3dB profile and back to 6dB
Will call EE tomorrow and grab corded phone to-day.
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I went through the associated rigmarole a couple of months ago, having reported the same / similar problems at the beginning of the year through my ISP. In all I have had 3 BT Openreach visits, and after each the problem disappeared for a while and then kept coming back. However, since the last visit things have been a lot better, and I am now on (what I think is a) very stable 34999 DS/5712 US, with a 3.6 DS/6.0 US SNR. I did notice that after all the shenanigans that my interleave level has risen from a fairly consistent ~750 to the present level of 1485. There is also no noise at all during either incoming or outgoing telephone calls.
Not sure if any of this is of any help in resolving your issue, but you may need multiple Openreach visits to finally get it sorted.
Good luck
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Thanks toulouse any info is most welcome as this is first time I've had telephone issues that either drops the VDSL SNRm or signal when in use, Just for interest have got hold of a corded phone and used option 2 QLT the line seems very quiet and SNRm drops again but this time no resync.
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You have now confirmed that the problem originates with the actual circuit (line) and not with the telephone currently being used.
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I'll be on the the phone to EE tomorrow and go through there check list just thought it might fix itself over the last 3 weeks.
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Get ready for this the Modem I was using was causing the SNRm to drop when using the phone ZyXEL 8924, I really don't understand how this could happen as the modem is located nowhere near the master socket 5C where the phone is plugged in it is using the data extension terminals into another room 8 meters away.
Billion 8800NL MK1 back in the same place as 8924 and Issue fixed
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Thank you for the update.
I'm glad to know that you have resolved the problem by swapping out the modem/router. However I am not sure what physical defect would give rise to that problem.
Puzzling. ???
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I too am puzzled how the modem could cause High Open type symptoms.... but glad you sorted it :)
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Nether do I BC the modem has Firmware version Version 1.00 AAKL 20 loaded into it yes a bit old but should not cause symptoms like this unless the power supply has become weak and modem struggles to maintain a correct current/amp, yes this modem has dual VOIP and is trying to kick in during a call but it would need to be connected to a phone which has two sockets at the back of modem.
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I've given the problem some more thought . . .
All modems (modem/routers) have a high-pass filter before the analogue front end (AFE). At the very minimum that high-pass filter will be two capacitors, one in each leg of the pair. The normal condition, with the modem (modem/router) powered on and the telephone not in use, will be a high impedance condition. When the telephone is in use, it loops the pair and a low impedance condition prevails. That's perfectly acceptable and is part of the design specification.
Now suppose one of those two capacitors that form the high-pass filter is somewhat degraded, is out of specification, is a bit manky. The impedance will not be anywhere near as high as expected by the design. When the telephone is used, the modem's (modem/router's) interface will be shunted far more than that of the design specification and it reacts adversely . . . That adverse reaction could, possibly, be as was described in the opening post.
As to whether that is a sensible proposal? :shrug2:
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burakkucat if you want I could send this ZyXEL 8924 to you free everything works just the above issue
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Thank you for that generous offer but I shall decline. :)
Perhaps there is a member, with good eyesight and an oscilloscope, who could fault-find and effect a repair?
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No worrys BC I fully understand I hate to admit it but opening it up and testing the circuitry with soldering iron at the ready would have been a joy 15 years ago but not these days don't get me wrong I will try my best to get a broken thing working again but my patience is very low
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A further thought . . .
Have you tested with the SSFP removed and connecting the VMG8924 (& a telephone) via a "rat's tail" micro-filter directly to the NTE5C? I am not impressed with the construction quality of the NTE5C and its associated "clip-on" face-plates.
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Think I was a bit over enthusiastic with change of modem it's now showing a drop of SNRm on the Billion 8800NL when phone is in use but not as much 0.5dB compared to 2.0dB ZyXEL.
I am not impressed with the construction quality of the NTE5C and its associated "clip-on" face-plates.
And neither am I BC, look I'm not one of those people who just hate new designs or the like yet a good hard wobble of the 5C unit will throw up some errors in the stats especially where the phone jack plugs in.
Previous 1 day time = 24 hours 0 sec
FEC: 4753656 28
CRC: 3510 13
ES: 81 13
SES: 61 0
UAS: 113 52
LOS: 3 0
LOF: 21 0
LOM: 3 0
>
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Think I was a bit over enthusiastic with change of modem it's now showing a drop of SNRm on the Billion 8800NL when phone is in use but not as much 0.5dB compared to 2.0dB ZyXEL.
Ah, so perhaps the problem does originate elsewhere.
. . . a good hard wobble of the 5C unit will throw up some errors in the stats especially where the phone jack plugs in.
Hmm, that is definitely not good. I would be very tempted to revert back to a NTE5/A plus a Mk 3 SSFP.
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I'll be honest with you my VDSL2 circuit has not been able to hold onto its sync at best 1 day 3 hours and worse case 4 re-syncs per day in the last 7 weeks and reason why I changed the modem from billion to zyxel to see if it made any difference unfortunately it had the opposite effect for 3 weeks.
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You have any long term data plots so we can analyse?
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No Chrysalis the RPi was decommissioned last year as the circuit was very steady with 130 days under its hood, work is being done in the village to create 40 new homes, the only thing I can put a finger guess is when it rains or prolonged dampness and we know how hard that is find and fix.
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Having taken some of BC's advice I examined the Master socket 5C over the weekend as it definitely was the culprit as I was able to recreate issues by slamming the door which next to Master Socket stud wall and pulling on the phone cord and so on, Took the MS 5C apart outer plate and unscrewing inner part then rechecking the cam connections then reassembling it back in as tight as it would go.
So now getting close to 2 days uptime and better looking errors and no SNRm drop at all when using the phone.
Since Link time = 1 days 21 hours 55 min 47 sec
FEC: 9351262 91
CRC: 50 68
ES: 34 62
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
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I'm glad to know that you have finally established the guilty party.
NTE5C :no: (My early 1980s NTE5/A is still serving me well.)
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You don't have a link close by for the MK3 do you ? the last OR engineer stole the one a bought from mr telephone
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I've only got a few eBay links --
https://www.ebay.co.uk/itm/Genuine-BT-Openreach-VDSL-Faceplate-MK3-For-NTE5a-Master-Socket-BNIB/123850224864
https://www.ebay.co.uk/itm/Genuine-BT-Openreach-VDSL-Faceplate-MK3-For-NTE5a-Master-Socket-BNIB/223693919926
https://www.ebay.co.uk/itm/Genuine-BT-Openreach-VDSL-Faceplate-MK3-For-NTE5a-Master-Socket-BNIB/323940704039
https://www.ebay.co.uk/itm/Genuine-BT-Openreach-VDSL-Faceplate-MK3-For-NTE5a-Master-Socket-BNIB/352785276932
https://www.ebay.co.uk/itm/Genuine-BT-Openreach-VDSL-Faceplate-MK3-For-NTE5a-Master-Socket-BNIB/352811867536
Hopefully one of those will fulfil your need.
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Cheers BC but now when I think about it would need a NTE5/A and a MK3 SSFP and also the front plate which has phone and Internet sockets so that is 3 parts in total if my memory serves me right
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So you will require something like one of the following --
https://www.ebay.co.uk/itm/BT-Linebox-Nte5-Wifi-Landline-Brand-New-In-Packaging/352696645317
https://www.ebay.co.uk/itm/Master-socket-NTE5A-Instructions-Genuinely-BT/123603872962
https://www.ebay.co.uk/itm/NTE5a-Master-Socket-IDC-With-Backbox-BT-Virgin/233116642198
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Er Em well I was thinking if it was possible to purchase all three as one unit but looks impossible so the Openreach Installed NTE5c and MK4 SSFP will have to stay in situ until I can find a better Openreach Backstop than what is currently available and leave with no deal ;D
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I'm sure that I've recently seen the full "three piece set" but nothing was obvious in my quick checks, earlier this evening.
Edited to add: Found it . . .
https://www.ebay.co.uk/itm/bt-openreach-mk3-vdsl-filter-nte5a-master-socket-bK-box-idc-tool/323722037126
. . . but look at the price! :swoon:
Another one, at a slightly better price --
https://www.ebay.co.uk/itm/In-original-packaging-Genuine-Openreach-MK3-Filter-NTE5a-Tel-Socket-screws/264374979548
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No worrys BC you have excelled yourself, and if I installed all this stuff it's a sure bet that if an Openreach engineer needed to visit my premises in the future they would just remove it and install a NTE5C and MK4 SSFP and back to square one.