Kitz Forum
Broadband Related => Broadband Technology => Topic started by: William Grimsley on January 29, 2016, 05:21:20 PM
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Hi everyone!
I currently own a BT Home Hub 5 (Type B) and was trying to do some DLM testing on it. However, how many times I restart it, disconnect and reconnect the DSL cable or turn the Hub off and on, my noise margin will not rise and the data rate won't go down. Again, I know you're probably thinking "Why would you want to do this?" but I just wanted to see how I could get DLM to kick in on the Hub?
Here are my current line stats:
1. Product Name: HomeHub5
2. Serial number: +076286+1505012010
3. Firmware version: v0.07.05.0A13-BT (Type B) Last updated 10/12/2015
4. Board version: 01
5. VDSL uptime: 0 days, 01:00:56
6. Data Rate: 8063 / 40000
7. Maximum Data Rate: 8063 / 44263
8. Noise Margin: 6.4 / 7.3
9. Line Attenuation: 29.6 / 25.9
10. Signal Attenuation: 0.0 / 0.0
11. Data sent/received: 55.0 MB / 772.3 MB
12. Broadband username: bthomehub@btbroadband.com
13. BT Wi-fi: Yes
14. 2.4GHz wireless network/SSID: BTHub5-F2GC
15. 2.4GHz wireless connections: Enabled (802.11 b/g/n (up to 144 Mb/s))
16. 2.4GHz wireless security: WPA2 Only (Recommended)
17. 2.4GHz wireless channel: Automatic (Smart Wireless)
18. 5GHz wireless network/SSID: BTHub5-F2GC
19. 5GHz wireless connections: Enabled (802.11 a/n/ac (up to 1300 Mb/s))
20. 5GHz wireless security: WPA2 Only (Recommended)
21. 5GHz wireless channel: Automatic (Smart Wireless)
22. Firewall: Default
23. MAC Address: 4c:09:d4:b4:2a:4e
24. Software variant: -
25. Boot loader: 0.5.0-BT (Tue Jun 17 18:52:56 2014)
Many thanks.
William
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Again, I know you're probably thinking "Why would you want to do this?" but I just wanted to see how I could get DLM to kick in on the Hub?
6. Data Rate: 8063 / 40000
7. Maximum Data Rate: 8063 / 44263
8. Noise Margin: 6.4 / 7.3
Have to confess I am still wondering why you would want DLM to intervene on your line.
How long have you had your FTTC connection? DLM tends to do nothing for the first 24/48 hours..
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You could say, I'm "different".
I've had BT Infinity 1 since 27/04/2015.
The main aim is just to see what would happen, I've disconnected and reconnected the DSL cable 2 more times and here are my new line stats:
1. Product Name: HomeHub5
2. Serial number: +076286+1505012010
3. Firmware version: v0.07.05.0A13-BT (Type B) Last updated 10/12/2015
4. Board version: 01
5. VDSL uptime: 0 days, 01:18:16
6. Data Rate: 8043 / 40000
7. Maximum Data Rate: 8043 / 43417
8. Noise Margin: 6.5 / 7.2
9. Line Attenuation: 29.6 / 25.9
10. Signal Attenuation: 0.0 / 0.0
11. Data sent/received: 65.7 MB / 335.9 MB
12. Broadband username: bthomehub@btbroadband.com
13. BT Wi-fi: Yes
14. 2.4GHz wireless network/SSID: BTHub5-F2GC
15. 2.4GHz wireless connections: Enabled (802.11 b/g/n (up to 144 Mb/s))
16. 2.4GHz wireless security: WPA2 Only (Recommended)
17. 2.4GHz wireless channel: Automatic (Smart Wireless)
18. 5GHz wireless network/SSID: BTHub5-F2GC
19. 5GHz wireless connections: Enabled (802.11 a/n/ac (up to 1300 Mb/s))
20. 5GHz wireless security: WPA2 Only (Recommended)
21. 5GHz wireless channel: Automatic (Smart Wireless)
22. Firewall: Default
23. MAC Address: 4c:09:d4:b4:2a:4e
24. Software variant: -
25. Boot loader: 0.5.0-BT (Tue Jun 17 18:52:56 2014)
Maybe it's G.INP saying "Stop it, William!".
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If I wanted to try this out, I probably wouldn't be starting from there ;)
I don't see the HH5B as being a useful tool in "seeing what happens" to the line - so I would almost certainly swap to a model that gave me access to all the stats. However, I don't use BT Infinity, so I'm not sure what limitations that ISP may inadvertently place on your connection.
I've used unlocked HG612's modems with a broadcom chipset (in combination with a standalone router), and a Billion 8800NL combined router/modem with a newer broadcom chipset.
Once you've got to the point that you can see all the line statistics, then you're in a much better position to see what happens.
As it stands, I suspect that G.INP is active (though you can statically figure out what cab type you have to see if this is likely), and is much less likely to then add draconian DLM interventions through a few power cycles. You might need a *serious* number nowadays ... but I've not heard anyone try deliberately since G.INP went live.
Still want to do it? I'd go for 5-6 line disconnects (not power cycles), and see. Then a burst of a few more if needed.
As it stands, you might not see a drop in sync speed. Your attainable is already 10% higher than the package sync speed, and that might be enough to mask the FEC overhead when/if DLM turns it on. You're probably more like to see a change in latency first.
Talking of latency, I'd use a "ping monitor" or "BQM" from thinkbroadband to monitor latency. However, this is only worthwhile if you have a static IP, and your router responds to pings. I'm not sure the HH5 does that.
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If I wanted to try this out, I probably wouldn't be starting from there ;)
I don't see the HH5B as being a useful tool in "seeing what happens" to the line - so I would almost certainly swap to a model that gave me access to all the stats. However, I don't use BT Infinity, so I'm not sure what limitations that ISP may inadvertently place on your connection.
I've used unlocked HG612's modems with a broadcom chipset (in combination with a standalone router), and a Billion 8800NL combined router/modem with a newer broadcom chipset.
Once you've got to the point that you can see all the line statistics, then you're in a much better position to see what happens.
As it stands, I suspect that G.INP is active (though you can statically figure out what cab type you have to see if this is likely), and is much less likely to then add draconian DLM interventions through a few power cycles. You might need a *serious* number nowadays ... but I've not heard anyone try deliberately since G.INP went live.
Still want to do it? I'd go for 5-6 line disconnects (not power cycles), and see. Then a burst of a few more if needed.
As it stands, you might not see a drop in sync speed. Your attainable is already 10% higher than the package sync speed, and that might be enough to mask the FEC overhead when/if DLM turns it on. You're probably more like to see a change in latency first.
Talking of latency, I'd use a "ping monitor" or "BQM" from thinkbroadband to monitor latency. However, this is only worthwhile if you have a static IP, and your router responds to pings. I'm not sure the HH5 does that.
Hi WWWombat,
Thanks for your detailed post.
I will try the "burst" of disconnections and reconnections and see what happens. I am thinking about getting a different router at some point but noise margin and data rate is good enough for me. When you mean "disconnections" do you mean unplug the DSL cable and plug it back in several times in say an hour?
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I must have done at least 10 disconnections and reconnections of the DSL cable but surprisingly the line stats are very similar with no increase in interleaving!
1. Product Name: HomeHub5
2. Serial number: +076286+1505012010
3. Firmware version: v0.07.05.0A13-BT (Type B) Last updated 10/12/2015
4. Board version: 01
5. VDSL uptime: 0 days, 00:01:13
6. Data Rate: 8011 / 40000
7. Maximum Data Rate: 8011 / 43627
8. Noise Margin: 6.4 / 7.3
9. Line Attenuation: 29.6 / 26.0
10. Signal Attenuation: 0.0 / 0.0
11. Data sent/received: 0.7 MB / 0.1 MB
12. Broadband username: bthomehub@btbroadband.com
13. BT Wi-fi: Yes
14. 2.4GHz wireless network/SSID: BTHub5-F2GC
15. 2.4GHz wireless connections: Enabled (802.11 b/g/n (up to 144 Mb/s))
16. 2.4GHz wireless security: WPA2 Only (Recommended)
17. 2.4GHz wireless channel: Automatic (Smart Wireless)
18. 5GHz wireless network/SSID: BTHub5-F2GC
19. 5GHz wireless connections: Enabled (802.11 a/n/ac (up to 1300 Mb/s))
20. 5GHz wireless security: WPA2 Only (Recommended)
21. 5GHz wireless channel: Automatic (Smart Wireless)
22. Firewall: Default
23. MAC Address: 4c:09:d4:b4:2a:4e
24. Software variant: -
25. Boot loader: 0.5.0-BT (Tue Jun 17 18:52:56 2014)
As far as I remember, DLM doesn't work on the fly with VDSL so maybe I'll see a change later on this evening/overnight?
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When monitoring for errors, DLM leaves its actions until overnight.
However, if it sees something severe, it can take action immediately. Multiple disconnections would normally be one of those severe things ... but perhaps things need to be even worse nowadays, and it leaves most "tidying up" to G.INP.
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When monitoring for errors, DLM leaves its actions until overnight.
However, if it sees something severe, it can take action immediately. Multiple disconnections would normally be one of those severe things ... but perhaps things need to be even worse nowadays, and it leaves most "tidying up" to G.INP.
That's interesting. I'll continue with the disconnections today and see what happens and I'll report back. Hopefully, this thread will explain the actions of DLM a bit better.
I'm just wondering, is it something to do with that I'm disconnecting the DSL cable out of the router instead of the SSFP so the router knows something's wrong hardware wise or would this make no difference?
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Several more disconnections and reconnections later and the line stats show no significant change... This G.INP is very strong!
1. Product Name: HomeHub5
2. Serial number: +076286+1505012010
3. Firmware version: v0.07.05.0A13-BT (Type B) Last updated 10/12/2015
4. Board version: 01
5. VDSL uptime: 0 days, 00:00:13
6. Data Rate: 8099 / 40000
7. Maximum Data Rate: 8099 / 43854
8. Noise Margin: 6.3 / 7.3
9. Line Attenuation: 29.6 / 26.0
10. Signal Attenuation: 0.0 / 0.0
11. Data sent/received: 0.0 MB / 0.0 MB
12. Broadband username: bthomehub@btbroadband.com
13. BT Wi-fi: Yes
14. 2.4GHz wireless network/SSID: BTHub5-F2GC
15. 2.4GHz wireless connections: Enabled (802.11 b/g/n (up to 144 Mb/s))
16. 2.4GHz wireless security: WPA2 Only (Recommended)
17. 2.4GHz wireless channel: Automatic (Smart Wireless)
18. 5GHz wireless network/SSID: BTHub5-F2GC
19. 5GHz wireless connections: Enabled (802.11 a/n/ac (up to 1300 Mb/s))
20. 5GHz wireless security: WPA2 Only (Recommended)
21. 5GHz wireless channel: Automatic (Smart Wireless)
22. Firewall: Default
23. MAC Address: 4c:09:d4:b4:2a:4e
24. Software variant: -
25. Boot loader: 0.5.0-BT (Tue Jun 17 18:52:56 2014)
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If you want the DLM to take action on your line you will need to introduce errored seconds on your line, this can be done by using the eletrical arching method 240volts AC is recommend for this experiment get close to the modem and if you can monitor the errored seconds during each arc that's even better.
This experiment is the same as a lighting stike most modems hate this kind of stuff so you will need to spark that 250v cable until you reach 2880 errored seconds or just above.
And keep doing this for an hour then wait another 24 hours to see if the DLM has taken notice ;)
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If you want the DLM to take action on your line you will need to introduce errored seconds on your line, this can be done by using the eletrical arching method 240volts AC is recommend for this experiment get close to the modem and if you can monitor the errored seconds during each arch that's even better.
This experiment is the same as a lighting stike most modems hate this kind of stuff so you will need to spark that 250v cable until you reach 2880 errored seconds or just above.
And keep doing this for an hour then wait another 24 hours to see if the DLM has taken notice ;)
Hang on, what? I don't want to electricute myself! So, all these DSL cable disconnections and reconnections aren't going to do anything?
What a stupid idea!
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NOT a good idea :o :'( :thumbdown: :no: :swoon: :angel:
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Hang on, what? I don't want to electricute myself! So, all these DSL cable disconnections and reconnections aren't going to do anything?
The DLM retrains does count you would need 20 or so disconnects during 24 hours onthe Speed profile which your are on it would only take 10 disconnects in 24 hours for me being on the Standard profile.
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Going down the route of inducing errors is another way to get DLM to pay attention, but I'm not sure I'd be doing it that way! Some people have been able to induce errors by turning heating elements on and off, and some people by switching fluorescent tubes on and off.
Disconnecting the phone line, or power-cycling the modem, certainly used to trigger DLM interventions. Some have seen it at low values, and I've seen it at 5 or 6 within one day (the RCD in the fusebox was tripping out regularly).
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What a stupid idea!
Not as stupid as wanting the DLM to act on your circuit, even as an experiment to get the notice of the DLM is just stupid the Kitz forum is to help others lines to be unnoticed by the DLM :)
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Well, surely it's still worthy of investigation when people face DLM problems?
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What are you investigating? We know why and how DLM takes action.
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Well, surely it's still worthy of investigation when people face DLM problems?
Not really as we know why & when the DLM takes action it's been well documented by Kitz and as a member I don't want your line to see the DLM because from your posted stats it look way better than my line :cool:
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I've been tempted to try soldering an ECI, to see what happens ... and then I might want to induce DLM.
Luckily the wife needs a stable line for work, so I've not managed to combine time and opportunity yet!
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Well, I managed to do it! New line stats:
1. Product Name: HomeHub5
2. Serial number: +076286+1505012010
3. Firmware version: v0.07.05.0A13-BT (Type B) Last updated 10/12/2015
4. Board version: 01
5. VDSL uptime: 0 days, 00:01:19
6. Data Rate: 8495 / 39999
7. Maximum Data Rate: 8954 / 44602
8. Noise Margin: 6.6 / 7.9
9. Line Attenuation: 29.5 / 25.9
10. Signal Attenuation: 0.0 / 0.0
11. Data sent/received: 1.2 MB / 0.1 MB
12. Broadband username: bthomehub@btbroadband.com
13. BT Wi-fi: Yes
14. 2.4GHz wireless network/SSID: BTHub5-F2GC
15. 2.4GHz wireless connections: Enabled (802.11 b/g/n (up to 144 Mb/s))
16. 2.4GHz wireless security: WPA2 Only (Recommended)
17. 2.4GHz wireless channel: Automatic (Smart Wireless)
18. 5GHz wireless network/SSID: BTHub5-F2GC
19. 5GHz wireless connections: Enabled (802.11 a/n/ac (up to 1300 Mb/s))
20. 5GHz wireless security: WPA2 Only (Recommended)
21. 5GHz wireless channel: Automatic (Smart Wireless)
22. Firewall: Default
23. MAC Address: 4c:09:d4:b4:2a:4e
24. Software variant: -
25. Boot loader: 0.5.0-BT (Tue Jun 17 18:52:56 2014)
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I've been tempted to try soldering an ECI, to see what happens ... and then I might want to induce DLM.
Luckily the wife needs a stable line for work, so I've not managed to combine time and opportunity yet!
Yes, I have thought about driving into my Huaewi cabinet...
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:lol: "Soldering an ECI" meant one of the CPE modems, not the DSLAM box on the street corner!
As for the line stats, all I can really see is a difference in upstream statistics (where "max" is now > "actual"). The downstream "actual" has altered from a consistent 40000 to 39999. Being one or two bytes below target is quite usual; the change might signify something, but equally might not - this result is much more ambivalent/
Knowing what you were doing, I'd hazard a guess that DLM has intervened upstream.
Ironically, that wasn't one of the changes I'd have expected!
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:lol: "Soldering an ECI" meant one of the CPE modems, not the DSLAM box on the street corner!
As for the line stats, all I can really see is a difference in upstream statistics (where "max" is now > "actual"). The downstream "actual" has altered from a consistent 40000 to 39999. Being one or two bytes below target is quite usual; the change might signify something, but equally might not - this result is much more ambivalent/
Knowing what you were doing, I'd hazard a guess that DLM has intervened upstream.
Ironically, that wasn't one of the changes I'd have expected!
Yes, it is interesting. I think G.INP has been turned off as normally G.INP lets the download data rate reach 40000 kbps but with it off it can't reach that. Anyway, we'll see what happens tonight after I do some more disconnections and reconnections of the DSL cable. :lol:
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If you connect a Huawei HG612 with the latest unlocked firmware, you will be able to see what G.INP is set to.
Unfortunately with the HH5 you have no clue.
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So, after 17 more disconnections and reconnections of the DSL cable, DLM takes action! New line stats:
1. Product Name: HomeHub5
2. Serial number: +076286+1505012010
3. Firmware version: v0.07.05.0A13-BT (Type B) Last updated 10/12/2015
4. Board version: 01
5. VDSL uptime: 0 days, 04:21:09
6. Data Rate: 8447 / 35000
7. Maximum Data Rate: 9038 / 44340
8. Noise Margin: 6.3 / 9.6
9. Line Attenuation: 29.4 / 25.9
10. Signal Attenuation: 0.0 / 0.0
11. Data sent/received: 218.1 MB / 124.7 MB
12. Broadband username: bthomehub@btbroadband.com
13. BT Wi-fi: Yes
14. 2.4GHz wireless network/SSID: BTHub5-F2GC
15. 2.4GHz wireless connections: Enabled (802.11 b/g/n (up to 144 Mb/s))
16. 2.4GHz wireless security: WPA2 Only (Recommended)
17. 2.4GHz wireless channel: Automatic (Smart Wireless)
18. 5GHz wireless network/SSID: BTHub5-F2GC
19. 5GHz wireless connections: Enabled (802.11 a/n/ac (up to 1300 Mb/s))
20. 5GHz wireless security: WPA2 Only (Recommended)
21. 5GHz wireless channel: Automatic (Smart Wireless)
22. Firewall: Default
23. MAC Address: 4c:09:d4:b4:2a:4e
24. Software variant: -
25. Boot loader: 0.5.0-BT (Tue Jun 17 18:52:56 2014)
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It looks like the DLM is capping the line rate.
That is what Id expect it to do. Well in actual fact I would first expect it to increase error protection and then cap.
The HH5B is far from the best router to test with as it doesnt give you any g.inp/retransmission values, so you dont know what its doing on the error protection side. Need to get a modem/router such as a HG612/Billion/Zyxel to do some proper testing.
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It looks like the DLM is capping the line rate.
That is what Id expect it to do. Well in actual fact I would first expect it to increase error protection and then cap.
The HH5B is far from the best router to test with as it doesnt give you any g.inp/retransmission values, so you dont know what its doing on the error protection side. Need to get a modem/router such as a HG612/Billion/Zyxel to do some proper testing.
That's exactly what I've done. Want some stats? Here you go!
Stats recorded 02 Feb 2016 15:41:10
DSLAM/MSAN type: BDCM:0xa48c / v0xa48c
Modem/router firmware: AnnexA version - A2pv6F039g1.d24m
DSL mode: VDSL2 Profile 17a
Status: Showtime
Uptime: 2 hours 35 min 45 sec
Resyncs: 0 (since 02 Feb 2016 13:59:08)
Downstream Upstream
Line attenuation (dB): 25.8 0.0
Signal attenuation (dB): Not monitored
Connection speed (kbps): 35000 8493
SNR margin (dB): 9.7 6.7
Power (dBm): 12.0 5.8
Interleave depth: 8 2
INP: 54.00 53.00
G.INP: Enabled
RSCorr/RS (%): 0.0001 0.0010
RSUnCorr/RS (%): 0.0000 0.0000
ES/hour: 0 0
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Agree that it looks like a capped speed. The new stats suggest that retransmission settings were ramped up a lot - standard INP values are in the low 40's, so 54 and 53 are quite high. It probably took a number of steps to get there. The graphs that the HG612-statistics programme could have generated would have been interesting.
Seeing how the modem reacts with the interleaving block size, and the FEC overhead, and more of the retransmission settings would have been useful too, but none are visible in those stats. What modem is it?
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Unfortunately, I didn't have this router when I was doing the testing but it's the Billion 8800NL.
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Well done that was a fast delivery for the Billion 8800NL that sounds like Amazon :-\
no more manual disconnects of the modem from now on, get your good self set-up on MDWS and upload the stats from the billion using either DSLstats or HG612_Modem_stats if you have already not done so.