Kitz Forum

Broadband Related => Broadband Hardware => Topic started by: peteS on January 28, 2021, 06:54:38 PM

Title: Giving up on Draytek (modems) - switching over to 8924....
Post by: peteS on January 28, 2021, 06:54:38 PM

Hi Everyone

First post here - the forum's been a huge help in getting ready for my switch over today from Draytek to using a 8924 as my vdsl modem.

I'm using a Draytek 2860 as my router in a relatively complex home network setup - 3 subnets, seperate vlans for various things, multiple ssids in different subnets, site to site vpn to an azure virtual network etc..  It actually all works pretty well, but the modem side of the 2860 has always been a little unstable.  Certainly not un-performant - just unstable.  My line will typically sync at 80/20 with SNRM of about 8db and I get throughput of about 72-73mb down and about 16 up.  However, it's unstable and has got worse of late  - drops several times each day.  The odd thing is the DSLAM never does anything about it - just resyncs at high 70's and off we go again.  I had a Draytek 130 in a cupboard, so pulled that out and it's a bit better - maybe only drops once a day.  However, I'm on a Broadcom cabinet, with G.INP and, unusually, vectoring enabled (or at least the 130 thinks so).  So, going to give an 8924 a try and see if it'll settle down.  If not, I like the ability to cap the speed to try and force some stability, and if not, to get some really decent line stats to really see what's going on.

Pretty much all setup to switch over later.  v28 firmware installed with the v2 modem file to sort vectoring hopefully.

I had one question at the moment - what's the .rom file that's part of the standard firmware download from ZyXEL.  I've reset rom-d (although it's a retail device so likely didn't need it), and I'm not using the stock firmware anyway, but didn't know what the 1.00(AAKL.28)C0.rom was.  Should I do anything with it?

I don't think I can do anything to use the 8924 as a router as I need the seperate SSIDs in different VLANs, and it doesn't look like that's possible sadly.  Still, hopefully will at the very least let me gets some really decent insight into what's going in.  You can look forwards to lots of stats and graphs in the near future :-)

ta

pete S


Title: Re: Giving up on Draytek (modems) - switching over to 8924....
Post by: siofjofj on January 28, 2021, 07:14:20 PM
Welcome to the forum  :)

As far as I remember, the .rom file is a template you can fill in if you want to create your own ROM-D configuration. Once this is done, it can be uploaded to the router using FTP.

Good luck with the Zyxel on your connection. Indeed, if you have vectoring, you'll definitely want to give the A2pv6F039v2 modem code a go. Please let us know how you get on with it, there's so few people with vectoring it's difficult to reach any solid conclusions about which firmwares and modems are best as we have very few data points.
Title: Re: Giving up on Draytek (modems) - switching over to 8924....
Post by: peteS on January 28, 2021, 09:06:14 PM
Thanks for the info on the .rom.  I'll just ignore it then.

Currently working through trying to get a connection in bridge mode through the draytek.  I was running PPPOE through the 130, thought i'd just switch it over in bridge mode to the 8924.  Hmm.  PPPOE won't connect.  OK, plug the laptop into the 8923 and dial up networking - eh - that works.  Confused.  Bridge is working fine, connecting at full 80/20, but Draytek won't play.  Switch the 8924 over to router mode and the draytek to dhcp client, and it's fine of course, but double nating etc..  Currently no clue why the draytek pppoe client won't connect through the 8924 but is fine through the 130.
Title: Re: Giving up on Draytek (modems) - switching over to 8924....
Post by: peteS on January 28, 2021, 09:49:04 PM
Well, that was weird.  Took it all back to defaults, started again, did what I thought was exactly the same, and it all worked first time - well, second time I guess.

G.Vector:   Enable

... in the stats, so thinking i'm one of the few. 

Stats are looking very happy at the moment


====================================================================================
    VDSL Training Status:   Showtime
                    Mode:   VDSL2 Annex B
            VDSL Profile:   Profile 17a
                G.Vector:   Enable
            Traffic Type:   PTM Mode
             Link Uptime:   0 day: 1 hour: 0 minute
====================================================================================
       VDSL Port Details       Upstream         Downstream
               Line Rate:     19.999 Mbps       79.998 Mbps
    Actual Net Data Rate:     20.000 Mbps       79.999 Mbps
          Trellis Coding:         ON                ON
              SNR Margin:        9.2 dB           10.4 dB
            Actual Delay:          0 ms              0 ms
          Transmit Power:        7.3 dBm          12.6 dBm
           Receive Power:       -7.3 dBm         -11.9 dBm
              Actual INP:       47.0 symbols      48.0 symbols
       Total Attenuation:        0.0 dB          18.2 dB
Attainable Net Data Rate:     25.408 Mbps       98.612 Mbps
====================================================================================
  VDSL Band Status        U0      U1      U2      U3      U4      D1      D2      D3
  Line Attenuation(dB):    7.0    24.0    35.9     N/A     N/A    13.1    30.0    47.1   
Signal Attenuation(dB):    7.0    23.1    35.1     N/A     N/A    20.9    29.5    47.1   
        SNR Margin(dB):    9.0    9.2    9.2     N/A     N/A    10.4    10.4    10.4   
         TX Power(dBm):   -0.4   -19.6    6.4     N/A     N/A    8.5    7.8    7.0   
====================================================================================

            VDSL Counters

           Downstream        Upstream
Since Link time = 11 sec
FEC:      1410      0
CRC:      0      0
ES:      0      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Latest 15 minutes time = 2 min 48 sec
FEC:      3      0
CRC:      0      0
ES:      0      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Previous 15 minutes time = 15 min 0 sec
FEC:      209      0
CRC:      0      0
ES:      0      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Latest 1 day time = 1 hours 2 min 48 sec
FEC:      1410      0
CRC:      0      0
ES:      0      0
SES:      0      0
UAS:      157      157
LOS:      0      0
LOF:      0      0
LOM:      0      0
Previous 1 day time = 0 sec
FEC:      0      0
CRC:      0      0
ES:      0      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Total time = 1 hours 2 min 48 sec
FEC:      1410      0
CRC:      0      0
ES:      0      0
SES:      0      0
UAS:      157      157
LOS:      0      0
LOF:      0      0
LOM:      0      0
====================================================================================


Title: Re: Giving up on Draytek (modems) - switching over to 8924....
Post by: burakkucat on January 28, 2021, 10:53:30 PM
Welcome to the kitz forum.  :)

So second time lucky. There's nothing in the snapshot of the statistics that looks abnormal, to me.
Title: Re: Giving up on Draytek (modems) - switching over to 8924....
Post by: peteS on January 28, 2021, 11:56:57 PM
Thanks for the welcome.  The forum was a huge help in getting things going.  I understand the lab side of the house pretty well (a few dd-wrt powered waps with vlan configs were quite a steep learning curve a while back), but what happens the other side of the router is less well known.

As you say, I've never seen anything odd with the stats.  I get quick syncs speeds with good throughput, but it's not stable, even off a 9db or so snr.  Everything's fine, and then no connection, sometimes several times a day (less with the 130 vs the 2860).  Just trying to make it as rock solid as possible - even if it meant trading a little speed.

@siofjofj, yes, vectoring's definitely active.

xdslctl info --vectoring
xdslctl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason:    0
Last initialization procedure status:   0
Max:    Upstream rate = 25408 Kbps, Downstream rate = 99662 Kbps
Bearer: 0, Upstream rate = 20000 Kbps, Downstream rate = 79999 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Vectoring state: 1
Total error samples Ethernet pkts sent: 19266
Total error samples Ethernet pkts discarded: 0
Total error samples statuses sent: 9633
Total error samples statuses discarded: 0
 >

Any suggestions on what to track in dslstats much appreciated.

Pete S
Title: Re: Giving up on Draytek (modems) - switching over to 8924....
Post by: Alex Atkin UK on January 29, 2021, 05:24:36 AM
You've probably got the cleanest line of anyone on the forum, rare for anyone to sync at 79.9 these days let alone with SNRm to spare.
Title: Re: Giving up on Draytek (modems) - switching over to 8924....
Post by: tubaman on January 29, 2021, 07:27:02 AM
Very envious of those line stats - is the cabinet in your front room?  ;)
Title: Re: Giving up on Draytek (modems) - switching over to 8924....
Post by: peteS on January 29, 2021, 10:00:34 AM
:-)

I do realise how lucky I am on that front, to be sure.  I'm actually about 400 yards from the cabinet, which is about a mile from the exchange.  We're overhead wires most of the way to the cabinet as well, so even more lucky to not pick up problems, but we do live on the edge of a small town, so it's not exactly high density housing round here....  When we had a load of work done a few years ago, all of the internal wiring from where the line comes into the house was changed to nice, shielded cabling to protect it from any noise we generate, and it's got a mk4 face plate, no extensions etc., so i give it every chance....

TBH, the great stats are one of the reasons I'm digging into it - it shouldn't drop as regularly as it does.  We have plenty of snrm, and with the max attainable 20% above what we sync at, it should be rock solid.  But one day last week, it dropped 5 times during the work day.  Now, that was with the internal modem on the 2860, but it doesn't make sense.  Hence the move to 8924 to a) make it as stable as possible and b) let me run dslstats to try and figure out the cause.
Title: Re: Giving up on Draytek (modems) - switching over to 8924....
Post by: peteS on January 29, 2021, 01:22:34 PM
Hmm - interesting.  I got a drop down in SNRM down a few mins ago.  Overall, dropped from 10.5 to just below 9, and it was mostly D1 and D2, which both dropped by about 2-2.5db pretty much instantaneously and recovered again straight away.  Now, the line didn't actually drop, perhaps because the starting SNRM is a bit higher with the 8924 to start vs. the 2860 internal modem. 

Any thoughts on likely causes of something like this - something noisy externally perhaps?
Title: Re: Giving up on Draytek (modems) - switching over to 8924....
Post by: Alex Atkin UK on January 30, 2021, 09:30:19 AM
Almost certainly interference I'd think which could be from just about anything.  Its certainly not a big enough drop to worry about unless you lose sync.
Title: Re: Giving up on Draytek (modems) - switching over to 8924....
Post by: peteS on January 30, 2021, 12:03:07 PM
Almost certainly interference I'd think which could be from just about anything.  Its certainly not a big enough drop to worry about unless you lose sync.

My working assumption at the moment (based on a sample of one  ;) ) is that it was this type of drop that was causing my line drops and the higher baseline I have with the 8924 over the built in modem with the 2860 means that the line stayed up.

One thing I can say for sure at the moment is that siofjofj's firmware build with the v2 driver is brilliant so far on my vector/g.inp line.  If you've got vectoring, this certainly seems the route to go.  Many thanks siofjofj :)

pete S