DSL SNR
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page
- Plusnet Community
- :
- Forum
- :
- Help with my Plusnet services
- :
- Fibre Broadband
- :
- DSL SNR
DSL SNR
29-05-2018 11:09 PM - edited 29-05-2018 11:10 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Hi, My VDSL SNR is running very low (1.6dB at the moment). I believe this could be the cause of some issues I'm having. Is it possible to force the SNR up to 6dB from your end? Or is it more likely to be a fault on the line causing the issues? It's always been fairly low, around 4dB but of recent times it's dropped much lower.
Thanks.
Re: DSL SNR
30-05-2018 6:04 AM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Also, what router are you using?
We can't fix the target SNR, however I may be able to help in another way.
Bob Pullen
Plusnet Product Team
If I've been helpful then please give thanks ⤵
Re: DSL SNR
30-05-2018 7:25 AM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Moderator's note:
Thread moved from Broadband to Fibre Broadband.
Forum Moderator and Customer
Courage is resistance to fear, mastery of fear, not absence of fear - Mark Twain
He who feared he would not succeed sat still
Re: DSL SNR
on 30-05-2018 7:51 AM - last edited on 30-05-2018 10:34 PM by Mav
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Hi Bob,
No the connection doesn’t appear to be dropping altogether, at least, not very often as there was nothing in the last few days log to say so. I’m having momentary issues loading webpages, which I presume is being caused by error correction. Initially I thought it may be a dns issue but I changed the servers and the fault is still there.
I restarted the modem last night and it the snr has improved slightly. The issues I was having have gone again for now.
Modem/router is a cisco 887va. The account this relates to is the IP address that this message is posted from if you can see it. Output from the routers show controller vdsl 0 is below.
Thanks.
Just re-posting that controller output as its badly formatted above.
Firmware Source File Name
-------- ------ ----------
VDSL embedded VDSL_LINUX_DEV_01212008
Modem FW Version: 130205_1433-4.02L.03.A2pv6C035j.d23j
Modem PHY Version: A2pv6C035j.d23j
Trellis: ON ON
SRA: disabled disabled
SRA count: 0 0
Bit swap: enabled enabled
Bit swap count: 0 0
Line Attenuation: 0.0 dB 0.0 dB
Signal Attenuation: 0.0 dB 0.0 dB
Noise Margin: 3.8 dB 6.1 dB
Attainable Rate: 32732 kbits/s 2409 kbits/s
Actual Power: 12.2 dBm 6.1 dBm
Per Band Status: D1 D2 D3 U0 U1 U2 U3
Line Attenuation(dB): 25.5 78.6 90.3 13.1 65.2 N/A N/A
Signal Attenuation(dB): 25.5 78.6 N/A 13.1 63.6 N/A N/A
Noise Margin(dB): 3.8 3.9 N/A 6.2 6.1 N/A N/A
Total FECC: 945948113 29512
Total ES: 6878 5428
Total SES: 291 0
Total LOSS: 6 0
Total UAS: 146 146
Total LPRS: 0 0
Total LOFS: 5 0
Total LOLS: 0 0
DS Channel1 DS Channel0 US Channel1 US Channel0
Speed (kbps): 0 32008 0 2409
SRA Previous Speed: 0 0 0 0
Previous Speed: 0 34019 0 2461
Reed-Solomon EC: 5871 2571624 0 0
CRC Errors: 26297 26297 6004 6004
Header Errors: 0 0 0 0
Interleave (ms): 0.00 0.00 0.00 0.00
Actual INP: 2.01 50.00 0.00 0.00
Moderator's note by Mike (Mav): Duplicate post released from Spam Filter and removed from the thread.
Re: DSL SNR
30-05-2018 10:53 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Re: DSL SNR
30-05-2018 11:03 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Odd though. If your line is suffering, DLM should be pushing the target SNR back towards 6db (and potentially beyond) if things aren't stable
Bob Pullen
Plusnet Product Team
If I've been helpful then please give thanks ⤵
Re: DSL SNR
31-05-2018 9:12 AM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Sorry to hear you're having issues.
I've tested your line and it's not showing any major issues.
Unfortunately as Bob's advised we can't control the target SNR on fibre.
I'd recommend monitoring things and if they get worse raising a fault here
Re: DSL SNR
31-05-2018 8:02 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Thanks Bob/Matthew, I appreciate your responses.
FYI- Although I have a Cisco router and am familiar with Cisco IOS, I am still very much a novice/hobbyist studying for my CCNA Routing/Switching and my DSL knowledge is limited.
Bob, router uptime was a few weeks. I reset the router approx 12 hours ago. I have taken another snapshot of the show controller output. If you wouldn't mind, could you look it over and see if it looks normal? Especially the CRC errors as you mentioned previously? I know that CRC Errors are not normally present on internal interfaces unless there is potential cable damage, but don't know how that would translate to a DSL line.
Matthew, you mentioned there aren't any major issues, does this mean you did find some minor issues? I didn't know that you can't target a specific SNR with fibre. Thanks for that info.
I'm on an Exchange Only Line unfortunately and am a fair distance from the exchange in relation to what I would be from a street cabinet unfortunately, hence the slower than desired speed for VDSL. Don't know if this would influence the errors too?
Again, your help is very much appreciated.
Router output is below.
Thanks.
Modem FW Version: 130205_1433-4.02L.03.A2pv6C035j.d23j
Modem PHY Version: A2pv6C035j.d23j
Trellis: ON ON
SRA: disabled disabled
SRA count: 0 0
Bit swap: enabled enabled
Bit swap count: 0 0
Line Attenuation: 0.0 dB 0.0 dB
Signal Attenuation: 0.0 dB 0.0 dB
Noise Margin: 3.6 dB 6.2 dB
Attainable Rate: 30400 kbits/s 2409 kbits/s
Actual Power: 12.1 dBm 6.1 dBm
Per Band Status: D1 D2 D3 U0 U1 U2 U3
Line Attenuation(dB): 25.5 78.6 90.3 13.1 65.2 N/A N/A
Signal Attenuation(dB): 25.5 78.6 N/A 13.1 63.8 N/A N/A
Noise Margin(dB): 3.6 3.8 N/A 6.1 6.3 N/A N/A
Total FECC: 14362817 120
Total ES: 438 43
Total SES: 1 0
Total LOSS: 0 0
Total UAS: 35 35
Total LPRS: 0 0
Total LOFS: 0 0
Total LOLS: 0 0
DS Channel1 DS Channel0 US Channel1 US Channel0
Speed (kbps): 0 31364 0 2409
SRA Previous Speed: 0 0 0 0
Previous Speed: 0 0 0 0
Reed-Solomon EC: 20195 14362817 0 120
CRC Errors: 1030 1030 50 50
Header Errors: 0 0 0 0
Interleave (ms): 0.00 0.00 0.00 0.00
Actual INP: 2.01 51.00 0.00 0.00
Training Log : Stopped
Training Log Filename : flash:vdsllog.bin
Re: DSL SNR
31-05-2018 8:11 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
@speedychuck wrote:
Modem PHY Version: A2pv6C035j.d23j
This looks quite old. Perhaps upgrading the firmware might improve things.
Re: DSL SNR
31-05-2018 9:12 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
ejs, do you know if there is a later version which is supposed to be suited to BT lines? I read this firmware was specifically designed to work with them.
Cisco are not helpful or open when it comes to firmware downloads unless you have a service contract.
Re: DSL SNR
01-06-2018 10:56 AM - edited 01-06-2018 10:58 AM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
I've attached the test of your line below
Test Outcome | Pass |
Test Outcome Code | GTC_FTTC_SERVICE_0000 |
Description | GEA service test completed and no fault found . |
Main Fault Location | OK |
Sync Status | In Sync |
Downstream Speed | 29.7 Mbps |
Upstream Speed | 2.4 Mbps |
Appointment Required | N |
Fault Report Advised | N |
NTE Power Status | PowerOn |
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 | 1399.2 |
Upstream Rate Assessment | Reasonable |
Downstream Rate Assessment | Very Good |
Interference Pattern | Regular Interference Observed Daily |
Service Impact | No Impact Observed |
Interference Duration Longest Occurrence | ; 00:00 to 23:45 |
Interference Location | Customer Premise |
Interference Observed In Days | 14 |
Home Wiring Problem | Not Detected |
Downstream Policing Discard Rate | 0.0 |
Customer Traffic Level | Upstream and Downstream Traffic Detected |
Technology | VDSL |
Profile Name | 0.128M-40M Downstream 3dB, Retransmission High - 0.128M-10M Upstream, Error Protection Off |
Time Stamp | 2018-05-19T11:00:00 |
Parameters | MIN | MAX | AVG |
Down Stream Line Rate | 30.6 Mbps | 34.0 Mbps | 33.5 Mbps |
Up Stream Line Rate | 2.4 Mbps | 2.5 Mbps | 2.4 Mbps |
Up Time | 762.0 Sec | 900.0 Sec | 899.7 Sec |
Retrains | 0.0 | 1.0 | 0.0 |
Current and Last 15 Minute Bin Performance | ||
Parameters | Last Traffic Count(Upto 15 mins) | Current Traffic Count(Upto 15 mins) |
Start Time Stamp | 2018-06-01T09:30:14Z | 2018-06-01T09:45:14Z |
Ingress Code Violation | 0 | 0 |
Egress Code Violation | 0 | 0 |
Errored Seconds | 0 | 0 |
Severely Errored Seconds | 0 | 0 |
Unavailable Seconds | 0 | 0 |
At the time of the one I did yesterday there was a few errors but nothing major
Re: DSL SNR
01-06-2018 8:05 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
The Cisco firmware listed in the BT list of approved FTTC modems is 39m_B_38h3_24h.
I think it uses the same DSL chipset as the Openreach HG612 FTTC modem, the last firmware for them had A2pv6C038m.d24j, so I was thinking something similar to that might help.
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page