Kitz Forum

Broadband Related => FTTC and FTTP Issues => Topic started by: 111888 on October 19, 2023, 02:06:01 AM

Title: Line Attenuation (dB)
Post by: 111888 on October 19, 2023, 02:06:01 AM
On FTTC my Line attenuation is:    Line Attenuation (dB) 32.2 on upstream.

Is this too high?
Title: Re: Line Attenuation (dB)
Post by: RealAleMadrid on October 19, 2023, 08:36:21 AM
@111888 It is what it is and cannot be changed apart from moving closer to the FTTC cabinet. Purely dependent on your line length.
Title: Re: Line Attenuation (dB)
Post by: 111888 on October 19, 2023, 12:55:09 PM
@111888 It is what it is and cannot be changed apart from moving closer to the FTTC cabinet. Purely dependent on your line length.

I saw about 2,000 errors on upstream, only 5 errors on downstream, in 12 days up time.

When the router stays connected for longer than a week I notice I have issues with gaming, latency jumps around from the average 25 to 91 ms. gaming feels sluggish.  The Snr margin on upstream stays at 6.2, down stream stays at 3.0. giving me about 60mbps on down stream and 6.50 mbps on upstream.   Line attenuation is 14.8 on downstream, so does this indicate a fault on the upstream?
Title: Re: Line Attenuation (dB)
Post by: parkdale on October 19, 2023, 03:11:19 PM
What ISP are you with? How many times in the past month have you had to reboot the router?
Title: Re: Line Attenuation (dB)
Post by: 111888 on October 19, 2023, 03:52:55 PM
What ISP are you with? How many times in the past month have you had to reboot the router?

zen internet.

I am using a tp link router. I tried a different router by tp link called vr 400 v3, and this time it reports back saying I have a 2.5dB line attenuation on upstream, compared to 32.2 with the vr2800 router.

I reboot the router usually after a week as then it starts to feel sluggish.
Title: Re: Line Attenuation (dB)
Post by: Alex Atkin UK on October 19, 2023, 09:40:26 PM
Its not uncommon for routers to report attenuation wrong.  You'd need to be sat next to the cabinet for low single digits which would mean your SNRm would be a LOT higher and a full sync rate.  I'd say 32 sounds about right though.

Do you have the router Zen provided or renewed your contract with them at any point so could perhaps ask them to send their current model?
Title: Re: Line Attenuation (dB)
Post by: 111888 on October 20, 2023, 05:32:26 PM
Its not uncommon for routers to report attenuation wrong.  You'd need to be sat next to the cabinet for low single digits which would mean your SNRm would be a LOT higher and a full sync rate.  I'd say 32 sounds about right though.

Do you have the router Zen provided or renewed your contract with them at any point so could perhaps ask them to send their current model?

Yes I have tried the router isp supplied, same problem after about a week internet is very sluggish, slow.
Title: Re: Line Attenuation (dB)
Post by: 111888 on October 21, 2023, 01:41:02 PM
what can cause the internet to become slow and sluggish after a week of  up time?
Title: Re: Line Attenuation (dB)
Post by: parkdale on October 21, 2023, 04:50:46 PM
In my case the Vodafone router was ****. I changed to a Fritzbox... problem gone. The supplied router was forcing the line attn too low, 3.2db  >:D. Now runs at 6db no problem.
Be careful about rebooting you router too often as this can make to cab think you have a poor line and for the DLM to increase error correction etc.

Have you measured your packetloss via Thinkbroadband BQM? Mine goes up and down all the time causing Netflix to become pixilated and drop quality from 4k. Gaming is not too good either :(
There's nothing I can do as it's a problem with ISP congestion.

Modem/router choice is like Marmite... some people love them.. most hate them ;) It's YMMV, I do know that my mates TP Link router (VR600) gave an unrealistic down load speed for the line length to the cab!! Even the Openreach tech had a doubts as it was more that her equipment measured..

Title: Re: Line Attenuation (dB)
Post by: RealAleMadrid on October 21, 2023, 11:09:55 PM
@parkdale Your router cannot change the line attenuation, I presume you actually mean your signal to noise margin (SNRM) which is not set by the router either but by the Openreach DLM system.
Title: Re: Line Attenuation (dB)
Post by: mofa2020 on October 22, 2023, 01:59:19 PM
Just noting that the VR400 v3 uses Econet "Mediateck" chipset and VR2800 uses Broadcom one.
Title: Re: Line Attenuation (dB)
Post by: 111888 on October 22, 2023, 10:29:39 PM
Just noting that the VR400 v3 uses Econet "Mediateck" chipset and VR2800 uses Broadcom one.

source?
Title: Re: Line Attenuation (dB)
Post by: mofa2020 on October 22, 2023, 11:51:37 PM
source?

https://forum.openwrt.org/t/quality-of-the-vdsl-modem/105054/16  This for VR400 V3

https://forum.kitz.co.uk/index.php?topic=26056.0  This for VR2800
Title: Re: Line Attenuation (dB)
Post by: underzone on October 23, 2023, 07:58:57 AM
Good job mofa2020!
Title: Re: Line Attenuation (dB)
Post by: parkdale on October 23, 2023, 10:04:34 AM
@parkdale Your router cannot change the line attenuation, I presume you actually mean your signal to noise margin (SNRM) which is not set by the router either but by the Openreach DLM system.

Sorry for the confusion :-[... I meant Snr can be forced down. My downstream runs quite happily all day at 6db. 
Title: Re: Line Attenuation (dB)
Post by: mofa2020 on October 23, 2023, 01:40:59 PM
Good job mofa2020!

Thank you, I think TP-link is cutting costs down on some new versions even the VR600 v3 is MediaTek unlike v1 and v2.
Title: Re: Line Attenuation (dB)
Post by: 111888 on October 23, 2023, 06:24:39 PM
https://forum.openwrt.org/t/quality-of-the-vdsl-modem/105054/16  This for VR400 V3

https://forum.kitz.co.uk/index.php?topic=26056.0  This for VR2800

That is just some guy saying that, he doesn't have any sources to prove that either?

Only way to know for sure, is to open up the router