Kitz ADSL Broadband Information
adsl spacer  
Support this site
Home Broadband ISPs Tech Routers Wiki Forum
 
     
   Compare ISP   Rate your ISP
   Glossary   Glossary
 
Please login or register.

Login with username, password and session length
Advanced search  

News:

Pages: [1] 2

Author Topic: Hopefully someone can help me interpret these line stats?  (Read 1577 times)

rn123

  • Member
  • **
  • Posts: 11
Hopefully someone can help me interpret these line stats?
« on: September 10, 2021, 11:02:06 AM »

Morning all.

This place is turning into my go to place, so many helpful topics.

I have attached the current linestats from my HG612. I do also have a fritzbox 7530 I can try or the latest Vodafone Hub also.

I'm quite far from the exchange so those speeds are broadly ok, although I have had mid 50s before and 12 down. Looks like my SNR margin is way high. Is this something a new modem will cure or do I need to do anything else?
Logged

Weaver

  • Senior Kitizen
  • ******
  • Posts: 11459
  • Retd s/w dev; A&A; 4x7km ADSL2 lines; Firebrick
Re: Hopefully someone can help me interpret these line stats?
« Reply #1 on: September 10, 2021, 12:01:13 PM »

Yes, you’re absolutely correct, the downstream SNRM is way way too high. This is a bad thing and a good thing. It’s a bad thing because it slows you down. It’s a good thing provided that it is necessary and not just a screw-up within the BT Dynamic Line Management system which responds to detected fault symptoms by raising the target SNRM and taking other steps to make error correction far more powerful. If a high downstream SNRM is unnecessary then the target SNRM needs to be fixed, by a call out from an Openreach engineer, iirc. That would be arranged by your ISP. If a high downstream SNRM is necessary, then it is doing a good job for you and protecting you from errors caused by you line being bad; most likely either the line is faulty or it is picking up interference. That would be up to your ISP to diagnose and fix with an engineer callout. If the ISP can’t understand this, can’t diagnose it or manage a callout effectively then you need an ISPectomy, removal of the current ISP and replacement with a competent one. Either way, it’s over to your ISP next and see if they even know what a ‘downstream SNRM’ is. If they tell you to ‘turn it off and on again’ then I think you already have your answer.

You asked about different modems. The HG612 is a good but now very old modem and their components are deteriorating, as with pretty much all such kit. My own ZyXEL modems are pretty old too so I can’t talk. Unless it has developed a fault, which is I think unlikely to be the cause of any problem now, the HG612 will be fine. Were I in your position I would change it now because you will have to one day, before it dies anyway, and I would swap it out for a top of the range ZyXEL modem such as a VMG 8x24-B10A because they are superb and also have best-in-class detailed stats which will make it possible for us to help you to diagnose what’s going on now, and will allow you to keep an eye on future behaviour. Kitz, Burakkucat and I myself are amongst the many members who all swear by ZyXEL modems. The diagnostics available to you and which you posted above aren’t sufficiently detailed for us to make a full assessment.

Be aware that some ISPs are very unsupportive if a customer asks for help when using a modem or router that the ISP didn’t supply. This is not totally unreasonable but it’s extremely unhelpful to the customer. If this should happen, then it’s another reason to recommend an ISP switch.

Keep in touch, come back with further questions and do let us know how you’re getting on.
Logged

rn123

  • Member
  • **
  • Posts: 11
Re: Hopefully someone can help me interpret these line stats?
« Reply #2 on: September 10, 2021, 12:19:33 PM »

Yes, you’re absolutely correct, the downstream SNRM is way way too high. This is a bad thing and a good thing. It’s a bad thing because it slows you down. It’s a good thing provided that it is necessary and not just a screw-up within the BT Dynamic Line Management system which responds to detected fault symptoms by raising the target SNRM and taking other steps to make error correction far more powerful. If a high downstream SNRM is unnecessary then the target SNRM needs to be fixed, by a call out from an Openreach engineer, iirc. That would be arranged by your ISP. If a high downstream SNRM is necessary, then it is doing a good job for you and protecting you from errors caused by you line being bad; most likely either the line is faulty or it is picking up interference. That would be up to your ISP to diagnose and fix with an engineer callout. If the ISP can’t understand this, can’t diagnose it or manage a callout effectively then you need an ISPectomy, removal of the current ISP and replacement with a competent one. Either way, it’s over to your ISP next and see if they even know what a ‘downstream SNRM’ is. If they tell you to ‘turn it off and on again’ then I think you already have your answer.

You asked about different modems. The HG612 is a good but now very old modem and their components are deteriorating, as with pretty much all such kit. My own ZyXEL modems are pretty old too so I can’t talk. Unless it has developed a fault, which is I think unlikely to be the cause of any problem now, the HG612 will be fine. Were I in your position I would change it now because you will have to one day, before it dies anyway, and I would swap it out for a top of the range ZyXEL modem such as a VMG 8x24-B10A because they are superb and also have best-in-class detailed stats which will make it possible for us to help you to diagnose what’s going on now, and will allow you to keep an eye on future behaviour. Kitz, Burakkucat and I myself are amongst the many members who all swear by ZyXEL modems. The diagnostics available to you and which you posted above aren’t sufficiently detailed for us to make a full assessment.

Be aware that some ISPs are very unsupportive if a customer asks for help when using a modem or router that the ISP didn’t supply. This is not totally unreasonable but it’s extremely unhelpful to the customer. If this should happen, then it’s another reason to recommend an ISP switch.

Keep in touch, come back with further questions and do let us know how you’re getting on.

Thanks. So I am currently with vodafone, which I expect will fall into the no idea camp. I am currently looking at a switch to Zen, who would hopefully be better. I can then pick up on this, though hopefully the switch will help to reset things.

I have been look at Zyxel modems and they do seem good. Just seems difficult to track them down. I googled the model number you linked and it looks like you cant get them, unless I am being a bit thick which is entirely probable.
Logged

meritez

  • Content Team
  • Kitizen
  • *
  • Posts: 1623
Re: Hopefully someone can help me interpret these line stats?
« Reply #3 on: September 10, 2021, 12:29:45 PM »

Thanks. So I am currently with vodafone, which I expect will fall into the no idea camp. I am currently looking at a switch to Zen, who would hopefully be better. I can then pick up on this, though hopefully the switch will help to reset things.

I have been look at Zyxel modems and they do seem good. Just seems difficult to track them down. I googled the model number you linked and it looks like you cant get them, unless I am being a bit thick which is entirely probable.

Zyxels start from about £5 on ebay: https://www.ebay.co.uk/sch/i.html?_from=R40&_nkw=zyxel+vmg&_sacat=0&LH_TitleDesc=0&_sop=15



Logged

j0hn

  • Kitizen
  • ****
  • Posts: 4093
Re: Hopefully someone can help me interpret these line stats?
« Reply #4 on: September 10, 2021, 12:31:09 PM »

The SNRM isn't high.

The web interface on the HG612 is incorrect. The correct stats need gathered from logging in to the Telnet interface.
Logged
Talktalk FTTP 550/75 - Speedtest - BQM

Ixel

  • Kitizen
  • ****
  • Posts: 1282
Re: Hopefully someone can help me interpret these line stats?
« Reply #5 on: September 10, 2021, 12:36:50 PM »

EDIT: For further clarity, what I meant was if one was to go solely by the SNRM statistic then it looks like banding, however if the attainable rate and sync rate are correct then the SNRM statistic is wrong and you are indeed not banded.

It looks like you've been banded, aka capped, on your downstream sync rate, if the SNRM stats on the UI are correct that is. Looking at the attainable rate versus the line rate I'm inclined to believe the stats are wrong.

However, if we go with the assumption that they are miraculously correct... this can be a result of a line fault or simply disconnecting the modem too often in a timeframe. As a note, whenever you swap modems please try to allow a downtime window of at least 30 minutes. DLM takes 15 minute snapshots and shouldn't consider that an issue (e.g. its algorithm will believe that the user disconnected the modem intentionally) unless it's more rapid than 30 minutes. On FTTC/VDSL2 the SNRM target isn't physically adjusted by DLM, unlike ADSL2 for example, instead Openreach's DLM for FTTC/VDSL2 will band/cap the sync rate which can then nudge the actual SNRM up (but the target SNRM remains unchanged, Openreach's DLM never physically changes this setting higher than 6dB, on certain lines it can try to reduce this to as low as 3dB if certain conditions are satisfied).

Switching to Zen will likely trigger a DLM reset, certainly because it's a different backhaul at least. Hopefully with Zen you should get some assistance if required. It used to be the case that you could request a remote DLM reset via the ISP, not needing an engineer to come out and potentially pay a call out charge for what could be considered 'no fault found' - with no guarantee of a DLM reset either. I'm not sure if this option is still available, at the ISP's and then finally Openreach's discretion to accept or decline the request.
« Last Edit: September 10, 2021, 03:49:28 PM by Ixel »
Logged

Weaver

  • Senior Kitizen
  • ******
  • Posts: 11459
  • Retd s/w dev; A&A; 4x7km ADSL2 lines; Firebrick
Re: Hopefully someone can help me interpret these line stats?
« Reply #6 on: September 10, 2021, 01:09:35 PM »

Doh. I’ve just realised that stupidly I responded to two of your posts in a mixed up fashion, sorry about that.

Hmmm. I’m no expert on buying the latest ZyXEL models, Kitz or Burakkucat would be able to help there, and if need be, PM Kitz for advice on models and sourcing.  Admin note: Please don't do that!

All my many ZyXEL VMG 1312-B10A modems bar one came from Ebay. The first, ‘bar one’ unit came from my ISP, Andrews and Arnold. Don’t buy a VMG 1312-B10A, because even though they are excellent, the 8x24-B10A models are more up-to-date and if you wish to use one as a wireless modem-router they have modern wireless hardware in them. One thing to note: with the ZyXEL model numbers, not the last letter, often either an A (best DSL modem h/w) or D (less good DSL modem h/w). The difference is important, especially if you are on longer or more difficult lines, and I would say avoid the D models completely as there simply isn’t any need to compromise.

Another reason I suggested the 8x24-B10A is that, like my own 1312-B10A units, custom firmware written by our member "johnson" works on these models. This enhanced firmware has a number of technical improvements which are available provided you’re using the units as modems (as opposed to as modem-routers) and also that they have a built-in second web server in them which delivers stunning live stats, with stats history and graphing, with no other external software being required, other than a web browser. It underwent a tremendous amount of testing before the latest releases. I have the firmware running in my three VMG 1312-B10A units with never the slightest glitch and it therefore seems 100% reliable. Something that you might find very, very nice indeed to have as an option.
« Last Edit: September 10, 2021, 04:17:04 PM by roseway »
Logged

j0hn

  • Kitizen
  • ****
  • Posts: 4093
Re: Hopefully someone can help me interpret these line stats?
« Reply #7 on: September 10, 2021, 03:08:43 PM »

The line doesn't look banded. The sync is almost the same as the attainable. Actually the sync is ABOVE the attainable.

As I said above many of the figures on the web interface are in the wrong section or are just completely wrong.

The SNRM will be between 3-6dB, as it should be.

You don't need a new modem you just need to gather the correct stats via Telnet, SSH or by using an app like DSLStats.

Mid 50's down and 12 up, dropping to your current sync rates, is very consistent with crosstalk. That's actually a small drop compared to other lines.
« Last Edit: September 10, 2021, 03:13:22 PM by j0hn »
Logged
Talktalk FTTP 550/75 - Speedtest - BQM

Ixel

  • Kitizen
  • ****
  • Posts: 1282
Re: Hopefully someone can help me interpret these line stats?
« Reply #8 on: September 10, 2021, 03:46:12 PM »

The line doesn't look banded. The sync is almost the same as the attainable. Actually the sync is ABOVE the attainable.

I guess you didn't read beyond the first few words. I clearly said:
Quote
It looks like you've been banded, aka capped, on your downstream sync rate, if the SNRM stats on the UI are correct that is. Looking at the attainable rate versus the line rate I'm inclined to believe the stats are wrong.

I'm inclined to believe the stats are wrong, certainly going by attainable rate and sync rate it would prove he's not banded if those specific stats are correct. If SNRM, miraculously, was correct, it would indicate banding. I only continued on the basis that it was hypothetically banded. :)
Logged

digbey

  • Member
  • **
  • Posts: 59
Re: Hopefully someone can help me interpret these line stats?
« Reply #9 on: September 10, 2021, 04:36:53 PM »

I'm using an HG612 and I just compared the stats with the figures from DSL stats.
On the HG612  The SNR margin field actually shows the Line Attenuation.
The next two fields both seem to show the Output Power
Logged

rn123

  • Member
  • **
  • Posts: 11
Re: Hopefully someone can help me interpret these line stats?
« Reply #10 on: September 10, 2021, 05:06:01 PM »

The line doesn't look banded. The sync is almost the same as the attainable. Actually the sync is ABOVE the attainable.

As I said above many of the figures on the web interface are in the wrong section or are just completely wrong.

The SNRM will be between 3-6dB, as it should be.

You don't need a new modem you just need to gather the correct stats via Telnet, SSH or by using an app like DSLStats.

Mid 50's down and 12 up, dropping to your current sync rates, is very consistent with crosstalk. That's actually a small drop compared to other lines.

You were right as was Ixel in that the stats are wrong. Please see below (and also if you guys have any feedback on the stats below that would be great!, thanks!)

  Stats recorded 10 Sep 2021 17:04:14

DSL mode:                  VDSL2 Profile 17a
Status:                    Showtime
Uptime:                    2 days 6 hours 11 min 43 sec
Resyncs:                   0 (since 10 Sep 2021 17:03:12)
         
            Downstream   Upstream
Line attenuation (dB):     18.7      0.0
Signal attenuation (dB):   Not monitored      
Connection speed (kbps):   47993      10172
SNR margin (dB):           3.2      6.3
Power (dBm):               13.0      7.3
Interleave depth:          4      4
INP:                       54.00      39.00
G.INP:                     Enabled      Enabled
Vectoring status:          5 (VECT_UNCONFIGURED)      

RSCorr/RS (%):             8.8043      2.0167
RSUnCorr/RS (%):           0.0000      0.0000
ES/hour:                   0      0

Logged

Ixel

  • Kitizen
  • ****
  • Posts: 1282
Re: Hopefully someone can help me interpret these line stats?
« Reply #11 on: September 10, 2021, 05:40:14 PM »

From those recent statistics I can see that you have G.INP on both the downstream and upstream. DLM has also reduced your SNRM target to 3dB on the downstream by the looks of it, squeezing as much downstream speed out of the line as it can. Beyond that I don't know what else to say, it looks alright to me. Maybe others here will have some different comments or opinions.

EDIT: Looking at your first post, just want to mention that exchange distance typically has little bearing your FTTC connection's capabilities, it may only affect the bandplan in a small way in order to ensure ADSLx can co-exist without... well, being drowned out I guess. The important factors are typically, but not limited to, distance from the VDSL2/FTTC cabinet you're connected to, crosstalk and of course the quality of the line, internal wiring and such. It's only copper/ali to the cabinet and then fibre optic the rest of the way to the head end exchange.
« Last Edit: September 10, 2021, 05:47:53 PM by Ixel »
Logged

Weaver

  • Senior Kitizen
  • ******
  • Posts: 11459
  • Retd s/w dev; A&A; 4x7km ADSL2 lines; Firebrick
Re: Hopefully someone can help me interpret these line stats?
« Reply #12 on: September 10, 2021, 08:40:04 PM »

Shows you what I know. Good job someone with an actual HG612 pitched in.
Logged

rn123

  • Member
  • **
  • Posts: 11
Re: Hopefully someone can help me interpret these line stats?
« Reply #13 on: September 10, 2021, 09:04:01 PM »

Shows you what I know. Good job someone with an actual HG612 pitched in.

Your reply was super helpful. Learned a lot from reading the interpretation of the data. Thanks
Logged

rn123

  • Member
  • **
  • Posts: 11
Re: Hopefully someone can help me interpret these line stats?
« Reply #14 on: September 16, 2021, 02:52:23 PM »

As an update on this, I tested my hg612 from which I posted the stats, against a fritzbox 7530.

The line speed on my hg612 was almost at the attainable speed. The fritzbox is about 2mb faster on dl and identical upload. The fritzbox further showed an even higher still attainable which was a further 2.5mb ln top.

The hg612 has access to detailed stats and can access without a cable.

The fritzbox is seemingly a bit better sync. But haven't yet been able to access without a LAN cable, as it sits behind my router in bridge mode.

Assume most users would say stick with the fritzbox?
Logged
Pages: [1] 2