Kitz Forum

Broadband Related => FTTC and FTTP Issues => Topic started by: Deathstar on January 14, 2018, 10:19:58 AM

Title: Weird one or xdB?
Post by: Deathstar on January 14, 2018, 10:19:58 AM
Experts, would you mind having a look at my line stats on MDWS - Desthstar.

I am getting bursts of FEC's randomly, resulting in a Reason 1 DLM re-sync.

I've noticed each time, my SNR is reducing and Synchronization rates are increasing. I've not tested througput when directly plugged into my router to see if I am getting better throughput, though via WiFi no real improvement.

Some history, was using a AC68U, changed to a VMG1312-B10A last week, within 18 hours G.INP was applied, then two resets since with a reduction in SNR and and increase in Sync.
Prior to moving to the Zyxel, I had 35 days uptime then just before the replacement I had a few random disconnects always during the night. So timing was right to "upgrade'

Cheers

Chris

Sent from my SM-G930F using Tapatalk

Title: Re: Weird one or xdB?
Post by: bkehoe on January 14, 2018, 10:41:24 AM
Certainly looks like a classic case of xDb, you've gone from the standard 6dB target to 5dB and now you're on a 4dB target SNR. Presumably if DLM is happy you should see 3dB and probably a sync of 64 - 65mBit in a couple of days.
Title: Re: Weird one or xdB?
Post by: kitz on January 14, 2018, 10:12:18 PM
Looks like xDb to me.

DLM removed INP & Interleaved on the 10th and applied G.INP
12th 5dB
14th 4dB

You've gone from 47878 to 62153 and improved latency.   
The spikes look like a daily burst spike rather than constant.  Err Secs & LEFTRS looks fine so DLM appears to be happy.
Title: Re: Weird one or xdB?
Post by: Deathstar on January 17, 2018, 06:00:26 PM
Thanks for the reply.

I think it must be xDb, as I just got another burst of FEC's then a reinitialise and another drop in NM, with a corresponding increase in sync.
I wonder if the DLM is creating the FEC errors to instigate the drop in line to force a re-sync?