Kitz Forum

Broadband Related => FTTC and FTTP Issues => Topic started by: Chunkers on June 28, 2020, 10:06:55 AM

Title: FTTC - 2 lines to my house, same ISP, same hardware, different performance
Post by: Chunkers on June 28, 2020, 10:06:55 AM
Hi guys,

Probably a stupid question with a simple answer :

I have two lines coming into my house and since switching my second line from PlusNet they are both now with ZEN (:yay:),  IN the past I always attributed the differences to the ISP's.  Here is a summary the two from my modems :

(http://www.zen101388.zen.co.uk/images/WTF.jpg)

I don't really understand why ZEN 1 connects at 71 Mbps according to the modem and ZEN 2 reports slightly better attainable rates but seems stuck at 60 Mbps with plenty of SNR margin left - the nice round 60 Mbps number also suggests to me that this is some kind of 'cap' or limit that has been put on my line  :no:

Can any of you DSL wizards help me understand what this is telling me? 

Modems :    VMG8924-B10A
Firmwares : Johnson (v28 based)
Router :      pfSense APU2C4 thingy


Spank you very much!

C
Title: Re: FTTC - 2 lines to my house, same ISP, same hardware, different performance
Post by: jelv on June 28, 2020, 10:18:08 AM
How long is it since Zen 2 moved across from Plusnet?
Title: Re: FTTC - 2 lines to my house, same ISP, same hardware, different performance
Post by: RealAleMadrid on June 28, 2020, 10:27:28 AM
@Chunkers Looks like you are right about the speed being capped, line 2 is banded at 60Mbps. You need to get onto Zen and ask for a DLM reset assuming they are able to request it from Openreach.
Title: Re: FTTC - 2 lines to my house, same ISP, same hardware, different performance
Post by: Chunkers on June 28, 2020, 10:57:42 AM
How long is it since Zen 2 moved across from Plusnet?
Weirdly Zen 2 is the original ZEN line, I suspect it has been like this for a long time.

Apologies my numbering system is confusing, sorry about that!

C
Title: Re: FTTC - 2 lines to my house, same ISP, same hardware, different performance
Post by: Chunkers on June 28, 2020, 10:58:29 AM
@Chunkers Looks like you are right about the speed being capped, line 2 is banded at 60Mbps. You need to get onto Zen and ask for a DLM reset assuming they are able to request it from Openreach.

Thanks, I might pop them a quick email and see what happens

C
Title: Re: FTTC - 2 lines to my house, same ISP, same hardware, different performance
Post by: Alex Atkin UK on June 29, 2020, 10:25:08 AM
AFAIK they both use the same line profile so line performance shouldn't be any different between them on the same line, the same DLM rules apply.

The difference is what happens from the ISP onwards where I find Zen far more reliable for connecting to my VPN. (except yesterday, Zen had a complete meltdown with 20% packet loss)

However two lines to the same property can vary considerably:
(https://csdprojects.co.uk/forums/BroadbandLines2.png)
Title: Re: FTTC - 2 lines to my house, same ISP, same hardware, different performance
Post by: j0hn on June 29, 2020, 06:03:42 PM
The difference is what happens from the ISP onwards where I find Zen far more reliable for connecting to my VPN. (except yesterday, Zen had a complete meltdown with 20% packet loss)

Zen have had huge issues on their Manchester gateway since 23rd.
The TBB Zen section is full of reports of huge packet loss and low throughput in the evening.

Pretty poor of Zen they only acknowledged the issue today despite numerous reports from multiple users for nearly a week.
Title: Re: FTTC - 2 lines to my house, same ISP, same hardware, different performance
Post by: Alex Atkin UK on June 30, 2020, 12:26:29 PM
Zen have had huge issues on their Manchester gateway since 23rd.
The TBB Zen section is full of reports of huge packet loss and low throughput in the evening.

Pretty poor of Zen they only acknowledged the issue today despite numerous reports from multiple users for nearly a week.

I haven't been routed via Manchester since being on their Talk Talk Business backhaul.
Title: Re: FTTC - 2 lines to my house, same ISP, same hardware, different performance
Post by: Chunkers on July 03, 2020, 11:01:09 AM
Just to close this out, I checked my second line this morning after Zen responded saying they would request a DLM reset 2 days ago and hey presto!

Pretty much back to full speed, hurrah!

====================================================================================
    VDSL Training Status:   Showtime
                    Mode:   VDSL2 Annex B
            VDSL Profile:   Profile 17a
                G.Vector:   Disable
            Traffic Type:   PTM Mode
             Link Uptime:   1 day: 19 hours: 46 minutes
====================================================================================
       VDSL Port Details       Upstream         Downstream
               Line Rate:     19.362 Mbps       71.138 Mbps
    Actual Net Data Rate:     19.331 Mbps       71.139 Mbps
          Trellis Coding:         ON                ON
              SNR Margin:        6.0 dB            6.3 dB
            Actual Delay:          0 ms              0 ms
          Transmit Power:        7.6 dBm          13.0 dBm
           Receive Power:       -6.0 dBm         -10.0 dBm
              Actual INP:        0.0 symbols      48.0 symbols
       Total Attenuation:        0.0 dB          19.5 dB
Attainable Net Data Rate:     19.331 Mbps       72.087 Mbps
====================================================================================
Title: Re: FTTC - 2 lines to my house, same ISP, same hardware, different performance
Post by: Alex Atkin UK on July 03, 2020, 04:17:02 PM
It seems Zen have definitely been doing some work as now I AM routed via Manchester and my first hop latency is the lowest I've ever seen.

Never ever seen speedtest.net report single-digits before (high result as its across both WANs):
(https://www.speedtest.net/result/9702001109.png) (https://www.speedtest.net/result/9702001109)
Title: Re: FTTC - 2 lines to my house, same ISP, same hardware, different performance
Post by: j0hn on July 03, 2020, 04:43:52 PM
I get 6ms to speedtest.net but that's because it's my ISP's own test server in Edinburgh (Virgin).

I get 20ms to the wider internet.

Have you double checked you're actually connected to the Manchester gateway and it's not just using the Manchester server for Speedtests?

Are you closer to Manchester than London?
Title: Re: FTTC - 2 lines to my house, same ISP, same hardware, different performance
Post by: burakkucat on July 03, 2020, 05:27:52 PM
Are you closer to Manchester than London?

The cabinet, through which Alex's line connects, is associated with the Intake, Sheffield, exchange.

Without knowledge of the BT internals, I do not know where the head-end OLTs are located . . . but I'll hazard a guess that it is closer to Manchester than London. But then, of course, there is the question of where the BT <---> Zen interchange occurs . . .  :-\