Kitz Forum
Broadband Related => FTTC and FTTP Issues => Topic started by: kitz on April 21, 2016, 05:05:00 PM
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Something of which Ive only recently become aware of is the increasing number of people whose line has been banded by the FTTC DLM and it may be a larger number than we originally thought.
There's been a lot of 'me too' names and impossible to track over various threads, so ...
If you have been banded and your line is now stable can you please add below:
1) The speed rate at which you are banded.
2) Your max attainable rate
3) How long your line has been banded for.
4) If there was a trigger for the banding do you know what caused it and how long has it now been fault free.
5) A short summary of any additional info that may be relevant.
Your line must now be perfectly fine, restricted only by a DLM cap and capable of performing at a higher rate.
Please do not litter this thread with off topic posts, if there is an issue that needs more discussion, start a separate thread with more details and put a link to it in your post. I need to keep this thread clean and just trying to find out how widespread this problem is at the moment.
TIA.
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I'll start!
1) Downstream Rate: 34998 - 35000 Kbps.
2) Downstream Attainable Rate: 43500 - 46100 Kbps.
3) Nearly 3 months.
4) Maintenance of a BT Home Hub 5 (Type B) causing nearly 40 disconnects over the course of a few days.
5) Upgraded to the new BT Infinity 1 package "up to 52 Mbps" package on Monday, this did not cause a full DLM reset.
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I managed to get a DLM reset two days ago to remove my banding. Link to thread explaining everything: http://forum.kitz.co.uk/index.php/topic,16949.0.html (http://forum.kitz.co.uk/index.php/topic,16949.0.html)
I'll enter my stats below, feel free to delete my post if you feel it's not appropriate since my banding was removed via DLM reset 2 days ago.
1. 27,400kbps
2. 37,880kbps
3. Four months
4. I believe the HH5B was responsible for the instability on my line. I used it for the first few days when I swapped from Sky to BT but it was quite unstable, then proceeded to continue using my trusty HG612
5. Managed to get DLM reset by explaining via live chat that my line was banded and was running at 11DB SNR. The support agent booked me an boost engineer immediately. Only thing this boost engineer did was to order a DLM reset.
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1. 34999kbps
2. 44300 - 46200kbps
3. 45 days
4. A short period of severe instability which righted itself without intervention
5. Upgrade to new Infinity 1 cap had no effect on banding but removed G.Inp and introduced interleaving on 19th April. Interleaving removed 21st April SNRm 9.3dB. All stats from before banding to present viewable on MDWS user majorca72
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1) Currently Banded at 60000/20000. Prior to this I have been banded at 66999/20000 for 2-3(???) months after last BTO Engineer visit.
2) Max Attainable has been 70xxx+ since BTO Engineer visit. Voice fault (Faulty Linecard replaced.) fixed 13/04/2016 Max Attainable increased to 72xxx+.
3) Since 31-03-2016 13:20 local time (+/- 1 minute). [Reason: 1 Remote Defect Indicator/DLM]
4) Some weeks prior the power was lost to the town due to 'Digger issues' :).
The power had 'bounced a few times after the fix.
Also had difficulty getting PPP session that required multiple Power cycles of the router to get a PPP session established.
I suspect the multiple power losses eventually triggered DLM to intervene.
5) Full details of fault are noted in the following Plusnet Forum Post:
https://community.plus.net/t5/Fibre-Broadband/Yet-another-Happy-Customer-with-plummeting-Linespeeds-Thanks/td-p/1325539 (https://community.plus.net/t5/Fibre-Broadband/Yet-another-Happy-Customer-with-plummeting-Linespeeds-Thanks/td-p/1325539)
In a nutshell:
At 31-03-2016 13:20 local time (+/- 1 minute) the router re-synced and the speed dropped to 60000/20000 from 66999/20000.
I waited 10+ Days before raising the fault Ticket to allow for DLM possibly fixing the problem.
Fault Ticket raised on 13/04/2016
Voice fault raised with BT & fixed at exchange within 1-1.5 hrs ??? [Blinding speed by Plusnet/BT ;D ;D]
[Linecard replaced at exchange, as confirmed to me by the BT Engineer via Telephone call.]
DLM did not change the sync at all.
It has been at the quoted speed since.
The latest GEA Test on the line shows:
Voice Line Test Result Pass
Bridge Tap Not Detected
Radio Frequency Ingress Not Detected
Repetitive Electrical Impulse Noise Not Detected
Cross Talk Not Detected
Estimated Line Length In Metres 463.2
Upstream Rate Assessment Very Good
Downstream Rate Assessment Reasonable
Interference Pattern Not Detected
Service Impact No Impact Observed
Home Wiring Problem Not Detected
According to a Plusnet CSC Analyst " ... there is no DLM system on Fiber only ADSL." :-X :-X :o
I am now waiting a further 5 days to see if DLM re-syncs the line somewhere near the speed it should be capable of.
[I am following the suggested '10 Day' settling in period for DLM, after the Linecard [Voice] has been changed on my line at the Exchange.]
Max Attainable has increased on the line but I am still capped at 60000/20000.
The only thing DLM has done is the remove G.INP off the upstream at 08:12 15/04/2016.
Aardvark .................... the voice fault that was subsequently cleared at the Exchange, will have no bearing whatsoever on your FTTC broadband and DLM intervention. :)
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First time I was Banded
1. 28500
2. 40000-43000
3. 3 Weeks
4. Tried the Asus DSL N55U kept dropping connecting.
Went back on ECI modem and Homehub 3. Eventually BT sent out Boost engineer who moved Master Socket and DLM Reset
Second Time
1. 32999
2. 43000 - 47000
3. 7 Days
4. Again another new Modem this time Linksys x6200 kept rebooting. Upgrade to new Infinty 1 package expecting DLM reset. Full reset didn't happen just G.inp removed. Spoke to BT on line chat engineer attended same day ( don't ask I have no idea just turned up that afternoon) DLM reset and pair swap back to cab
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1) 22400
2) Approx 33000
3) 12+ months
4) original trigger was using the asus modem router which was extremely unstable on my line.
5) I do suffer from interference at night and s/n drops by around 1.5 db. Occasionally I will see a sudden drop of around 1 db for an hour or so then it will step back up - usually in early hours of the morning.
Sent from my iPhone using Tapatalk
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1) 43999
2) currently 46396 but I've seen higher, as high as in the 49xxxs
3) a hell of a long time, at least a year (from a post I found it could be coming up on 2 years).
4) I think it was caused by the ECI modem I was originally supplied with
5) my DS SNRM varies between 7 and 9.
if vectoring and/or 3dB target come to my cab I will absolutely want this removed.
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1st banding.
1) 67 mbps
2) 74-77mbps
3) 15 months+
4) Slow incremental flooding of an underground cable starting way back in probably before 2012 with a old joints needing replacing on my line but the engineer tried to get capacitance of my line in tolerance but could not find the issue in 2012, got FTTC in august 2013 with full 80mbps sync, It descended to 54mbps as the line got worse very progressively, it was fixed in late summer 2014 when it finally killed my neighbors phone line.
5) My line also had interleaving at the time, I needed a Lantic modem to get back to fast path. I also had a no dial tone fault in mid 2015 due to a faulty line card, I also reported slow broadband too in hope of getting a DLM reset. even with the fix of an existing fault he wouldn't do it.
2nd banding.
1) 60mbps
2) 74-77mbps
3) since early jan 2016, 4th month and counting
4) a day after a flooded joint fault was fixed it at the turn of 2016 , my line was down at 15-30mbps during that fault with no dial no dial tone, it did jump back upto 67mbps after the fault was fixed then the 60mbps banding kicked in over night.
5) I asked for a DLM reset the engineer wasn't sure what I meant, was not a broadband engineer,never entered my home and didn't do it. My line is on fast path with an Lantiq modem. I'm on An ECI cab, my line currently sits with a 9.5-10db noise margin, 51 days and counting without a resync. I have given up rebooting every month and hoping the banding gets removed, average errored seconds per day stands at 150 since the last resync, so the line should be a solid green for DLM.
Edit: now on 5693609s or 65.9 days uptime about to hit 66 days of no resyncs sub 250es ( average 150es ) per day probable solid green status, with no DLM relenting intervention.
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1) 34999
2) 39800
3) 63 days
4) I powered down my Billion 8800 for 10 hours overnight after I found it unresponsive at 9pm. At power-on it was seen to be banded.
5) Suspect faulty street light. Prior week had bursts of snrm downspiking at lighting-on time. It appeared to be fixed a few days later.
After powering-on router, 34999 band was seen, downstream INP had increased from normal 47 to 54 and upstream INP was applied at 44
2 days later the d/s INP reverted to 48, interleaving raised from 8 to 16 and upstream INP was removed.
D/s ES rates usually between 0 and 1 per hour, u/s ES rates between 1 and 5 per hour.
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1) 59993, 60000 after G.INP applied
2) No idea have Sky Q Hub (with no stats)
3) Since Feb 2015
4) Work on the house, electric on and off at different times. Modem disconnected whilst hall was plastered.
5) I am on an ECI cabinet. At the time of banding I had an Openreach ECI modem connected to the Sky Hub SR101. I am currently running the new Sky Q hub without any separate modem. I believe that G.INP was applied on 30th March as my latency went from 20ms to 12ms (has been 20ms for the whole time I have had FTTC) and my downstream SNR is between 9.2 and 9.6. BT dsl checker puts the clean line sync achievable between 69.1 and 53.6 (This estimate actually went up a few months ago as it was always 66 before).
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I joined to add my details to this thread
1) 34999
2) 39400
3) 13 months
4) Faulty modem power supply connector caused modem to keep powering off and on. Repaired by myself, now fault free for 13 months.
5) After the fault SNRm was increased to around 12db, after a few days fault free dropped to around 10db, then after about 3 months dropped to just under 9db and has remained there. I've had a couple of online chats with BT help line who have told me categorically the line is not banded, and that their systems clearly show no banding, though on one occasion it was said maybe 'wholesale' have capped the line. I was told to get an engineer out would definitely be chargeable and no guarantee that anything would change.
I'm not really so bothered as I don't think I would notice any change, more of an academic exercise for me, but thought I'd add my line to your thread.
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1) 39999
2) 48850
3) 3 months
4) electrical work possibly
5) Awaiting outcome of input from Exec Level Complaints
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1) 66999
2) 71000
3) 2 Months
4) I used to resync my modem every time a cross talker was removed to try and achieve a higher sync rate, which may have something to do with it.
5) G.INP was applied to the upstream for around two days along with a 66999 sync rate, the g.inp was then removed for no reason from the upstream then the sync rate has stayed the same for two months.
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1) 62026 / 6.0db
2) 65096 / 6.0db
3) approximately 4 weeks
4) Ginp was applied to line
5) Still got Ginp enabled but even with full resyncs with 30m waits will not connect anywhere near attainable rate. Used to get approximately 600-700 DS ES/day bit since Ginp I get none. Upstream still 200/day.
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Hi ktz392837
Thanks for that info, I don't think your line is banded.
1) 62026 isnt a banding figure
2) Your SNRm is at 6dB so there's nothing there to give any more speed.
If you want to post some more stats in another thread then I shall be happy to look further.
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Just a note.
Im gathering facts in this thread and when I get time, I intend to do something further with them
Thanks everyone who has taken the time to respond, I will keep this thread open until I have enough info :)
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Just thought I would resurrect this thread to see if there is any further news.
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Not sure if you're still collecting, but if so:
1. 34999 kbps
2. 55406 kbps
3. ~4 months
4. Tree height grown above phone line. During high winds and bad weather in early January, numerous (>10) line drops within a 6 hour period.
5. Tree height reduced. Fault raised 09-Jan-2016 as speed dropped to < 2 mbps download. Engineer attended 15-Jan-2016 and although speed had increased, OR changed face plate to SSFP. Upon re-connection sync immediately went to 14530/33478 with max of 14530/53928 and down SNR margin increased from 6.3 to 12.1dB. Line stable since with consistent speed and 6/13 up/down SNRM. Home Hub reboot / re-connection events as follows: 26-Jan, 04-Feb, 26-Mar, 29-Mar (hub change), 13-Apr, 27-Apr, 30-Apr, 11-May, 16-May, 17-May and 25-May. Those in bold/underlined text are thought to be HH5B 14 day reboot issue.
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1) The speed rate at which you are banded.
35000
2) Your max attainable rate
39308
3) How long your line has been banded for.
approx 90-100 days
4) If there was a trigger for the banding do you know what caused it and how long has it now been fault free.
Line was syncing up to 39+ Mbps when INP was released
Originally kicked in when I switched FROM HG612+HH5a to HH5a only. Attempted some PD as connection was unstable, and sync was only around 31 Mbps
Bought Archer VR900 and downstream was fine, but stuck at 35000, and upstream was poorer
Reverted back to HG612+HH5a and immediately totally stable but with 35000 cap
Line stable since this. In fact last resync was on connecting 50 days ago
5) A short summary of any additional info that may be relevant.
SNR currently is 7.8, so I'm not that far off max speed, but a little more would be good.
frustrating that this cap appears to be there
Not tried rebooting HG612 yet, and dare not go to HH5a modem
May switch ISP (Sky, SSE, talktalk) in July - but that's driven more by cost
BT HH does reboot about once every 3 weeks, appears to be a scheduled reboot
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Over half a year later and my line is still banded. Is DLM inept?
Now I'm wondering if the upcoming SNRm change by openreach might cause it to be released . I've also just had virgin cabling my street (not in service yet), but if neither of those work/happen I guess it's ISP fault time - but with a risk the problem isn't "bad enough"
Current sync is 34999 7.7dB / 6995 7.4dB
Any suggestions?
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My line is 60Mbit banded, but only for a month. I complained to my ISP and they said it looks like a stuck profile as my line stats have been very stable since 6th Dec (when I replaced faulty modem) and they have arranged for engineer to reset DLM tomorow. I will only be charged if they arrive at my door and nobody answers.
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Has anyone discovered how a line becomes banded in the first place it has only happened to me twice but that was errored seconds and after 14 days it was released and now with G.INP banded lines should have become a thing of the past.
Many random disconnects in 24 hours and more is what I think causes the DLM to cap a line for a long period.
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Mine got banded due to what I assume was a faulty modem, even though error seconds and re-syncs were low and line stats looks ok it still put quite severe banding on. As soon as I replaced the modem every single night it would reduce banding until it got stuck on 60mbit. Openreach engineer is looking at my line now, says there is a fault E side 300m away at the street cab but that should not affect broadband, he's gone to fix that before coming back and continuing with the DLM reset etc.
It makes all the difference when you actually get someone from Openreach who wants to fix stuff (and not some 3rd party contractor who's main aim is getting as many jobs done in a day to make money).
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1) The speed rate at which you are banded.
27397/6879
2) Your max attainable rate
29203/6879
3) How long your line has been banded for.
6-7 months
4) If there was a trigger for the banding do you know what caused it and how long has it now been fault free.
Lightning Storm in summer 2016 - not sure why DLM didn't pick this up as an area-wide event.
5) A short summary of any additional info that may be relevant.
Max attainable is sometimes higher. Sometimes as high as 32Mb depends on other cross talkers I guess. I'm a fair distance from my cabinet which is actually right outside the exchange (a little over 700 meters) previously an exchange only line. Sky fibre.
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That doesn't look like banding. Does your downstream rate change if you re-sync your modem?
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That doesn't look like banding. Does your downstream rate change if you re-sync your modem?
No it always syncs at this speed even when the attainable is higher.
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That doesn't look like banding. Does your downstream rate change if you re-sync your modem?
27.4mb is 1 of the banding levels so it does appear to be banded.
This link (https://community.plus.net/t5/Library/FTTC-DLM-What-it-is-How-it-works/ba-p/1322799) shows all of the banding levels.
As the attainable is only 29mb it isn't really impacting service, and hardly worth trying to get a DLM reset.
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This link (https://community.plus.net/t5/Library/FTTC-DLM-What-it-is-How-it-works/ba-p/1322799) shows all of the banding levels.
<b*cat plays devil's advocate> That link shows what Plusnet understands the situation to be with their own product. If the link was to an Openreach (or even a BT Wholesale) document, I would be more inclined to accept it as a generic rule. Also, we have no idea if Opcode is using a Plusnet provided service. ;)
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27.4mb is 1 of the banding levels so it does appear to be banded.
This link (https://community.plus.net/t5/Library/FTTC-DLM-What-it-is-How-it-works/ba-p/1322799) shows all of the banding levels.
As the attainable is only 29mb it isn't really impacting service, and hardly worth trying to get a DLM reset.
I think I need to go to specsavers, I hadn't spotted a 27.4 band there when I looked!! :-[
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1) 32398/7199
2) 33-35mb down, 8.2mb up
3) At least 9 months
4) 2 line faults, first time engineer reset DLM, 2nd time they didn't. Around jan 2016.
Sky won't do anything since it's above/within estimates.
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1. 14999
2. 19000
3. 15 weeks
4. Noisy line fault, fixed in October.
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1) 59995kbps
2) 62759kbps
3) 130 days
4) following about 2-3 months of problems with 3 BTOR visits
5) current SNRM 6.9 db was over 7 on initial re-sync recently
Stuart
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1, 35000kbps
2, 40000kbpa
3, over 6 months
4, very high ES for around a week for no obvious reason. Banding happened a few days in. High ES continued for a few more days then line stabilised without intervention.
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1. 66999 (u=19999) kbps
2. 73148 (u=25129) kbps
3. about 18 months
4. Possibly, family member trying to restart switched off broadband
5. snrm 7.6 (u=15.4). Line generally very stable.
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1. 48230 down 16998 up
2. 56000-57200 down 17653 up
3. 7 days since last dlm move was 46230 before for 35 days.
4. Was at 55700 then suddenly dropped one day :(
5. Upgraded line from 40 to 80Mb mid December.
Currently interleaved on down stream 8ms +3inp
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1. 60000 down 19455 up
2. 74312 down 19455 up
3. 5 months capped
4. Testing Netgear router ( Beta testing unit bad firware causing sync drops )
5. Current SNR is 18.7dB
Line was capped at 35 but after a fight with EE then raised a task to BTW and line now capped at 60
My understanding of the DLM system -
DLM uses a system called ‘Caution Counters’, this dictates, based on the quality and performance of your line what band/profile your line should be on as well as how long it will take before your line needs to be stable (Green quality) before increasing the speeds.
The counter then starts to count up to 9, the line remained green; the top profile would have been re-applied. In this case, the line started to error again, DLM reduced the profile again to try and control these errors.
You can see that there is a ‘barrier’ which shows at 0, 8, and 24. If your line had a bad day, you’d be put on barrier: 8, your line will then have to wait for 9 days (barrier=8 +1) before any positive profiles changes would be made. If your line continues to error/perform poorly, the barrier is increased, following the same rule as before. It’s important to bear in mind that it’s very unlikely that your profile will be set at its lowest without there being some kind of fault with the service, which an engineer would likely have visited and repaired and performed a DLM Reset.
At this point Openreach are also testing new 3dB SNR's in my area and so i am waiting for 25 days of sync before i reboot the modem.
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Why would you reboot the modem? Openreach don't need to wait for someone to reboot their modem before a new profile will be used, they could cause a reconnection whenever they want. I also heard somewhere that the XdB lower target SNRMs won't be applied to lines on which the DLM has already done something to reduce the speed.
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1. 34,999 down 5,500 up
2. 44,500 down 5,500 up
3. 5 months capped
4. As per Steven_belfast testing Netgear modem/router. Initially syncing at same speed as previous router, gradually lost 10 meg over beta test timescale.
Speed never recovered following re-installation of original router.
5. BT wholesale performance check shows IP profile 33.84 Mbps. When line was installed initial estimates of attainable speed were around 46 Mbps with a
guaranteed minimum of 35. Throughput for first year was in line with these estimates.
When contract was changed from Infinity 2 to Infinity 1 it took a month for BT to change software cap from 35 to 52. Speed estimates are now in
range of 30-39 so BT will not investigate blaming crosstalk.
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1. Current rate : 9999 / 39998
2. Max rate : 19395 / 71654
3. Like this since last October when 'speed issue' was fixed according to BT Fault reporting.
4. These stats were similar for about a year until start of July 2016, when e-mail arrived from BT trumpeting that my Infinity 1 'speed has been raised to 52Mbps'. Looked at stats and sure enough, Current rate downstream 50Mbps! Great, wonderful! Like this for a week.
Then went on holiday for a fortnight, modem left on as usual.
Came back, end of July. Router TP-Link TD-W9980 connecting and disconnecting dozens of times a day.
Put HG612 back on, synced and more stable, but around 27Mbps. Reported fault to online chat. Agent did remote test and said "there IS a speed issue here" and reported-on the fault.
Got phone call, "engineer needs to call," made appointment. On day of visit get another call, told fault external to premises, engineer doesn't need to call. Fault stayed open until October (!) then mysteriously became closed. Checked line speed, and was as above in item 1.
BT wholesale test says 7-8 / 35-38 and made new call to online agent who says "it's above the minimum for your line so we can't do anything."
Where is my 50Mbps I had for just a week in July? Doesn't "39998" look like an artificial cap?
Dave
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Yes I would think so.
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I noticed that DLM keeps enabling and disabling upstream G.INP, even though it's capped...
So rather than it waste it's changes in upload, I capped it at 6.5mb from 7.2mb pushing upload SNR to 14dB. Maybe it'll work on the downstream now.
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1) 14999
2) 18500-19500 (night-day) although immediately after resync it's about 20500
3) 15 days (see below)
4) Lots of RFI generated by stuff in my house, eliminated about 2.5 months ago
5) I used to be banded at 11399 due to lots of RFI, eliminated it and after about a month (5th Nov) modem resynced with new banding at 13096. A further 30 days later (5th Dec) modem resynced with new banding at 14999.
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1) 43999
2) currently 46396 but I've seen higher, as high as in the 49xxxs
3) a hell of a long time, at least a year (from a post I found it could be coming up on 2 years).
4) I think it was caused by the ECI modem I was originally supplied with
5) my DS SNRM varies between 7 and 9.
if vectoring and/or 3dB target come to my cab I will absolutely want this removed.
Appears to have been removed now, since the closure of mydslwebstats I can't say exactly when; however 8 or so days ago we had a power glitch (sustained low voltage on the mains for about 35 minutes) which may also have affected the cabinet, alternatively I powered our equipment off during the incident and it remained off for several hours. Sync is now 46553 with an snrm of 5.1dB