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: VDSL2 How many errors is acceptable?  (Read 5131 times)

j0hn

  • Kitizen
  • ****
  • Posts: 4093
Re: VDSL2 How many errors is acceptable?
« Reply #15 on: May 13, 2022, 04:02:25 PM »

500 CRCs in 5 days is nothing, realtively speaking

That's 500 errored packets, a packet is between 70 bytes and 1.5Mb.
Anytime these errors are captured, the packet is resent by the source

You'll have no issues in the real world with these kinds of errors

500 CRC can be 1 ES or 500 ES.

Whether any data is resent or not depends entirely on what the user is doing at the time (TCP/UDP/etc).
It could be that nothing is resent.

They are on different layers so there's not necessarily a correlation between the 2.
Logged
Talktalk FTTP 550/75 - Speedtest - BQM

Alex Atkin UK

  • Addicted Kitizen
  • *****
  • Posts: 5261
    • Thinkbroadband Quality Monitors
Re: VDSL2 How many errors is acceptable?
« Reply #16 on: May 13, 2022, 10:34:47 PM »

On a short line with high sync the chipset probably doesn't make a significant difference. However, on longer lines I can assure you it can very much make the difference between a stable, low errors, connection and an unstable ,high errors, one.
I say this from the experience of trying many different routers and chipsets on my ~800m line. From those I have tried a BCM63168 works best on my line. The common mode filter in my Zyxel VMG8924-B10A also gives an improvement on models without one.

Plus on an ECI cabinet with a really clean line, using a Lantiq modem that lets you tweak the SNRm is useful.

I only get full sync thanks to pushing a 4dB SNRm due to increased crosstalk over the years.
Logged
Broadband: Zen Full Fibre 900 + Three 5G Routers: pfSense (Intel N100) + Huawei CPE Pro 2 H122-373 WiFi: Zyxel NWA210AX
Switches: Netgear MS510TXUP, Netgear MS510TXPP, Netgear GS110EMX My Broadband History & Ping Monitors

j0hn

  • Kitizen
  • ****
  • Posts: 4093
Re: VDSL2 How many errors is acceptable?
« Reply #17 on: May 14, 2022, 01:26:24 PM »

Plus on an ECI cabinet with a really clean line, using a Lantiq modem that lets you tweak the SNRm is useful.

Same benefit for Huawei cabinets. Not all lines are deemed worthy of a sub 6dB target by the DLM.
Logged
Talktalk FTTP 550/75 - Speedtest - BQM

Alex Atkin UK

  • Addicted Kitizen
  • *****
  • Posts: 5261
    • Thinkbroadband Quality Monitors
Re: VDSL2 How many errors is acceptable?
« Reply #18 on: May 14, 2022, 09:48:59 PM »

Same benefit for Huawei cabinets. Not all lines are deemed worthy of a sub 6dB target by the DLM.

There are lines stable enough that wont just trigger DLM to increase the SNRm?
Logged
Broadband: Zen Full Fibre 900 + Three 5G Routers: pfSense (Intel N100) + Huawei CPE Pro 2 H122-373 WiFi: Zyxel NWA210AX
Switches: Netgear MS510TXUP, Netgear MS510TXPP, Netgear GS110EMX My Broadband History & Ping Monitors

Chrysalis

  • Content Team
  • Addicted Kitizen
  • *
  • Posts: 7382
  • VM Gig1 - AAISP L2TP
Re: VDSL2 How many errors is acceptable?
« Reply #19 on: May 16, 2022, 09:42:10 AM »

Same benefit for Huawei cabinets. Not all lines are deemed worthy of a sub 6dB target by the DLM.

I have done it three times, and all three times I got banded. :)  So at least in my experience the SNRM tweaking you have to be careful as the DLM doesnt seem to like you having a SNRM way below the target.  I guess ok if its not extreme though, like 5db instead of 6db.  I had a feeling it would happen this third time but given my line because of the FEC/interleaving cant sync above 74 anyway at 6db I gave it another go.  So didnt lose anything from the banding this time.
Logged

Alex Atkin UK

  • Addicted Kitizen
  • *****
  • Posts: 5261
    • Thinkbroadband Quality Monitors
Re: VDSL2 How many errors is acceptable?
« Reply #20 on: May 16, 2022, 12:19:17 PM »

I have done it three times, and all three times I got banded. :)  So at least in my experience the SNRM tweaking you have to be careful as the DLM doesnt seem to like you having a SNRM way below the target.  I guess ok if its not extreme though, like 5db instead of 6db.  I had a feeling it would happen this third time but given my line because of the FEC/interleaving cant sync above 74 anyway at 6db I gave it another go.  So didnt lose anything from the banding this time.

That's what I would expect as clearly DLM has a reason for not letting you have 3dB whereas on ECI its simply because there is no lower setting.
Logged
Broadband: Zen Full Fibre 900 + Three 5G Routers: pfSense (Intel N100) + Huawei CPE Pro 2 H122-373 WiFi: Zyxel NWA210AX
Switches: Netgear MS510TXUP, Netgear MS510TXPP, Netgear GS110EMX My Broadband History & Ping Monitors

j0hn

  • Kitizen
  • ****
  • Posts: 4093
Re: VDSL2 How many errors is acceptable?
« Reply #21 on: May 16, 2022, 03:19:17 PM »

That's what I would expect as clearly DLM has a reason for not letting you have 3dB whereas on ECI its simply because there is no lower setting.

The DLM only seems to apply banding to ECI lines for high ES.
I've never seen it apply banding on a Huawei line for high ES.
G.INP means even when pushing a line to 3dB the ES only increases a little especially when compared to the hundreds you get on fastpath.
Logged
Talktalk FTTP 550/75 - Speedtest - BQM

Chrysalis

  • Content Team
  • Addicted Kitizen
  • *
  • Posts: 7382
  • VM Gig1 - AAISP L2TP
Re: VDSL2 How many errors is acceptable?
« Reply #22 on: May 28, 2022, 09:52:18 PM »

Just for clarification ES was pretty much zero in my case, I did it on an interleaved line.
Logged
Pages: 1 [2]
 

anything