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Author Topic: speed loss on fttc  (Read 818 times)

chris3234

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speed loss on fttc
« on: December 26, 2020, 07:50:32 PM »

lost a good chunk for speed last few days dwon from around 15000-17000 mbp sync to 8800
QLN looks a bit differnt to how it used to bur not sure what it should look like for a good/bad one

aso below are current router stats
https://imgur.com/O35IuVn


Stats recorded 26 Dec 2020 19:49:16

DSLAM type / SW version:   BDCM:0xa4a1 (164.161) / v0xa4a1
Modem/router firmware:     AnnexA version - A2pv6F039t.d26d
DSL mode:                  VDSL2 Profile 17a
Status:                    Showtime
Uptime:                     0 hour 2 min 4 sec
Resyncs:                   1 (since 26 Dec 2020 19:30:44)
         
            Downstream   Upstream
Line attenuation (dB):     26.8      0.0
Signal attenuation (dB):   Not monitored      
Connection speed (kbps):   8799      3342
SNR margin (dB):           11.1      5.9
Power (dBm):               9.4      6.9
Interleave depth:          8      2
INP:                       55.00      40.00
G.INP:                     Enabled      Enabled
Vectoring status:          5 (VECT_UNCONFIGURED)      

RSCorr/RS (%):             0.0000      0.0000
RSUnCorr/RS (%):           0.0000      0.0000
ES/hour:                   0      0




adslctl info --stats
adslctl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason:    1
Last initialization procedure status:   0
Max:    Upstream rate = 3342 Kbps, Downstream rate = 15748 Kbps
Bearer: 0, Upstream rate = 3342 Kbps, Downstream rate = 8799 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Link Power State:       L0
Mode:                   VDSL2 Annex B
VDSL2 Profile:          Profile 17a
TPS-TC:                 PTM Mode(0x0)
Trellis:                U:ON /D:ON
Line Status:            No Defect
Training Status:        Showtime
                Down            Up
SNR (dB):        11.1            5.9
Attn(dB):        26.8            0.0
Pwr(dBm):        9.4             6.9
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tiffy

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Re: speed loss on fttc
« Reply #1 on: December 26, 2020, 09:11:25 PM »

You need to change the tone range on your DSLStats QLN graph and re-post, up to something like 2250 if you are on 40/10 service, can currently only see the U0 and D1 bands, would not imagine that your line could support 80/20 looking at the DS line attenuation, 26.8 dB indicates quite a long distance from the DSLAM cabinet, as a rough comparison, my line DS attenuation is 26.4 dB and my max synch rate is DS/US 40/5.3 Mbps..
Unless of course a line fault exists and your line length is not as indicated by DS attenuation figure.
Has this reading changed recently ?

As well as the re-scaled QLN a few more DSLStats snapshots would help greatly with line condition diagnosis, perhaps HLog, Bit Loading, Error Rates and SNRM.

Note that you have US G.Inp active, this is only applied by DLM if necessary and usually only persists for a few days, would be interesting to see the US error rates on your line.
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j0hn

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Re: speed loss on fttc
« Reply #2 on: December 26, 2020, 11:37:04 PM »

Downstream is capped/banded by DLM at 8.8Mb.

This is usually due to multiple resyncs in a short time period.
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chris3234

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Re: speed loss on fttc
« Reply #3 on: December 27, 2020, 03:58:42 PM »

You need to change the tone range on your DSLStats QLN graph and re-post, up to something like 2250 if you are on 40/10 service, can currently only see the U0 and D1 bands, would not imagine that your line could support 80/20 looking at the DS line attenuation, 26.8 dB indicates quite a long distance from the DSLAM cabinet, as a rough comparison, my line DS attenuation is 26.4 dB and my max synch rate is DS/US 40/5.3 Mbps..
Unless of course a line fault exists and your line length is not as indicated by DS attenuation figure.
Has this reading changed recently ?

As well as the re-scaled QLN a few more DSLStats snapshots would help greatly with line condition diagnosis, perhaps HLog, Bit Loading, Error Rates and SNRM.

Note that you have US G.Inp active, this is only applied by DLM if necessary and usually only persists for a few days, would be interesting to see the US error rates on your line.
ginp has been on the lline for 2+ years  even when the conection was good


here is the larger graph

https://imgur.com/8agnZWg


hlog
https://imgur.com/Q9djZz3

this is current error rates the look to have gone through the roof to waht they used be around 20-30 per day befor
Total time = 22 hours 30 min 14 sec
FEC:            18046511                38381
CRC:            3440            0
ES:             791             0
SES:            40              0
UAS:            78              58
LOS:            1               0
LOF:            8               0
LOM:            4               0
Retr:           1
Latest 15 minutes time = 14 sec
FEC:            0               0
CRC:            0               0
ES:             0               0
SES:            0               0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
Retr:           0
Previous 15 minutes time = 15 min 0 sec
FEC:            157             0
CRC:            0               0
ES:             0               0
SES:            0               0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
Retr:           N/A
Latest 1 day time = 22 hours 30 min 14 sec
FEC:            18046511                38381
CRC:            3440            0
ES:             791             0
SES:            40              0
UAS:            78              58
LOS:            1               0
LOF:            8               0
LOM:            4               0



bit loading graph showing all the tones

https://imgur.com/clOoMLh

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tiffy

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Re: speed loss on fttc
« Reply #4 on: December 27, 2020, 08:13:12 PM »

Quote
ginp has been on the lline for 2+ years  even when the conection was good
Yes, as stated previously, DS G.Inp is applied by default and remains with either a low or high profile, I believe your line would almost certainly be high profile, look at "Bearer 0 INPRein", 0=low, 1=high profile.
Have never seen US G.Inp remaining active for more than a few days, it's application normally mitigates the US errors which caused DLM to apply it in the first instance and is removed again.
The fact that US G.Inp has remained active would lead me to believe that there is an abnormally high US error rate beyond that which G.Inp can mitigate.

Your QLM graph certainly doesn't look healthy to me on the D1 and D2 bands, this is reflected in the bit loading graph in the D1 range between tones 200 & 320 (approx.) where there is zero bit loading.
The D2 band also has practically zero bit loading, doesn't look "normal" to me.

Many of the forum patrons are much more qualified than myself to comment on the QLN and HLog graphs, I can only compare to my own line which has a similar DS attenuation and assumed length, hopefully a second opinion will be offered in due course.

As j0hn has mentioned, multiple re-synch's within a short time span will be likely to incur unwanted DLM actions which can be very difficult and time consuming  to remove, some may even require a DLM reset via your ISP. 
« Last Edit: December 27, 2020, 08:20:00 PM by tiffy »
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burakkucat

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Re: speed loss on fttc
« Reply #5 on: December 27, 2020, 09:12:59 PM »

Unfortunately I am unable to review any of the plots that have been uploaded to imgur.com . . .

Something "odd" occurred with that hosting site, a while ago, and now all it displays, for me, is a black screen. (Other persons, in the Thinkbroadband Forum, also experience the black screen effect.)
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chris3234

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Re: speed loss on fttc
« Reply #6 on: December 27, 2020, 09:32:15 PM »

Unfortunately I am unable to review any of the plots that have been uploaded to imgur.com . . .

Something "odd" occurred with that hosting site, a while ago, and now all it displays, for me, is a black screen. (Other persons, in the Thinkbroadband Forum, also experience the black screen effect.)

try these missed the attacment button on here last time
« Last Edit: December 27, 2020, 09:34:54 PM by chris3234 »
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burakkucat

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Re: speed loss on fttc
« Reply #7 on: December 27, 2020, 10:29:51 PM »

Hmm . . .

The QLN plot is decidedly "messy". There seems to be a lot of spurious RF ingress. It's almost as if the pair is showing poor AC-balance. That effect is probably responsible for the "messy" US1 band and high frequency end of the DS2 band in the corresponding Hlog plot.

Overall, it appears that the pair (carrying your circuit) is troubled by something. Exactly what, I wouldn't like to guess.
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tiffy

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Re: speed loss on fttc
« Reply #8 on: December 28, 2020, 04:15:39 PM »

Quote
Unfortunately I am unable to review any of the plots that have been uploaded to imgur.com . . .

Something "odd" occurred with that hosting site, a while ago, and now all it displays, for me, is a black screen. (Other persons, in the Thinkbroadband Forum, also experience the black screen effect.)
The imgur.com links still work on my Win 10 Home desktop PC, strange!

As you have discovered, direct attachments are quick and easy although limited to 3 per post.

As b*cat concurs, there would appear to be something not quite right on your line and performance is not as good as it should be relevent to the assumed line length.
Can you possibly post a DLMStats SNRM graph, preferably over a longish time scale, at least a day, usually a good indication of overall line noise?

I think you will have to get your ISP involved, you have not mentioned who this is?
Wonder if anything has changed on your local house circuit recently, wired extension or phone added?

Assuming you have a BT/OR NTE5A/C master socket you should try your modem/router directly plugged into the test socket which will eliminate any extension wiring and any possible SSFP filter issues, your ISP will almost certainly ask you to do this anyway with a warning that OR could charge for any local wiring issues they find/rectify on a subsequent engineers visit.
Lots of guidance available here on how to achieve this, a very simple process depending on where your master socket is situated.

Do you have another modem/router you could substitute preferable with stat's extraction capability via DSLStats as per your existing modem/router, ie., Broadcom chip set? 
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mofa2020

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Re: speed loss on fttc
« Reply #9 on: December 28, 2020, 04:30:31 PM »

The imgur.com links still work on my Win 10 Home desktop PC, strange!

It works perfectly for me, Win 10 pro PC..
« Last Edit: December 28, 2020, 05:43:02 PM by mofa2020 »
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chris3234

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Re: speed loss on fttc
« Reply #10 on: December 28, 2020, 05:11:41 PM »

I works perfectly for me, Win 10 pro PC..

ONLy other router is a isp provided DG8041W THAT HAS NO only has basic stats listed on the web gui
house has no phone extentions or phone conected

DSL synchronization status:   Up
Connection status:   Showtime
Upstream line rate (kbit/s):   3247
Downstream line rate (kbit/s):   7872
Maximum upstream rate (kbit/s):   3246
Maximum downstream rate (kbit/s):   16788
Upstream noise safety coefficient (dB):   5.6
Downstream noise safety coefficient (dB):   13.2
Line standard:   Vdsl2_ANNEX_B
Upstream line attenuation (dB):   12.0
Downstream line attenuation (dB):   25.1
Upstream output power (dBm):   7.0
Downstream output power (dBm):   10.2
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tiffy

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Re: speed loss on fttc
« Reply #11 on: December 28, 2020, 07:51:38 PM »

ONLy other router is a isp provided DG8041W THAT HAS NO only has basic stats listed on the web gui
house has no phone extentions or phone conected

OK, would still connect your stat's enabled modem/router to the master socket, directly, no "rats tail" filter required as you won't be connecting a phone, this will positively eliminate any extension wiring that you may not be aware of (even though no phone is connected) and the master socket SSFP filter which have been known to go faulty on rare occasions.
If at all possible in this mode and to be able to evaluate the changes, re-connect whatever you are running DSLStats on and full time monitor.
Suggest you set DSLStats Graphs/Sampling/Time per Page to 1 day for this exercise.
After at least 24 hrs, re-post stat's graphs including SNRM.

May be a bit difficult to engineer depending on where your master socket is but believe this is the best way to establish if you have an internal line or hardware issue, it's a standard first line fault finding request made by virtually all ISP's and could certainly save you a quite hefty fee from OR should an internal fault be identified by an OR engineer during any future fault investigation.

You still have not mentioned who your ISP is? 

Do be careful regarding too many re-synch's in a short time period although as j0hn has suggested earlier, the line may already be capped for that reason.
Some very good information on DLM Process available here, well worth a read:
https://kitz.co.uk/adsl/DLM.htm
 
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chris3234

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Re: speed loss on fttc
« Reply #12 on: December 29, 2020, 09:13:35 AM »

theres is no externension wiring and nothing conected to the back of the faceplate and i cant connect me router diret to the test socket as its a phone line type conection andf i dont have a seperate filter any more chucked them out when i got a filtered faceplate fitted and i know that dlm hasnt taken action because of anything of my end as untill the other day the router has not been disconnected for 12 month othen then an occasinal power cutisp is talktalk not that it makes much of a differnce with fibre
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tiffy

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Re: speed loss on fttc
« Reply #13 on: December 29, 2020, 02:23:52 PM »

theres is no externension wiring and nothing conected to the back of the faceplate and i cant connect me router diret to the test socket as its a phone line type conection andf i dont have a seperate filter any more chucked them out when i got a filtered faceplate fitted and i know that dlm hasnt taken action because of anything of my end as untill the other day the router has not been disconnected for 12 month othen then an occasinal power cutisp is talktalk not that it makes much of a differnce with fibre
Looks like it's of to TT your ISP then.
Yes, all VDSL FTTP is managed by OR, your only contact is via your ISP of course.
Almost certainly TT will go through the "connect modem directly to test socket" procedure on initial contact.
Good luck with your issue.
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anything