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[Tacitus]

Is it possible to tell from the stats below whether I've been put on a banded profile? I'm currently on a capped 40mbps service which has been solid for ages but last week for some reason went haywire with the sync dropping to around 35Mbps and pings all over the place. It seems to have recovered as FECs are well down but is still well below what it was.

The current BBMonitor is here:
[url]https://www.thinkbroadband.com/broadband/monitoring/quality/share/b9a68d71b8f1a0a781e3b97ac9222f239e8fac84-25-05-2017/url]

Max attainable has hardly changed and is still around the 58 mark so I don't see why the sync speed should have dropped so much.

Modem is a Zyxel (Broadcom) some 1/4-1/2 mile from a Huawei 288 cabinet.

============================================================================
VDSL Training Status: Showtime
Mode: VDSL2 Annex B
VDSL Profile: Profile 17a
Traffic Type: PTM Mode
Link Uptime: 0 day: 20 hours: 56 minutes
============================================================================
VDSL Port Details Upstream Downstream
Line Rate: 10.057 Mbps 34.998 Mbps
Actual Net Data Rate: 9.999 Mbps 34.999 Mbps
Trellis Coding: ON ON
SNR Margin: 8.5 dB 13.5 dB
Actual Delay: 0 ms 0 ms
Transmit Power: 7.6 dBm 13.7 dBm
Receive Power: -6.9 dBm -5.7 dBm
Actual INP: 0.0 symbols 52.0 symbols
Total Attenuation: 0.0 dB 19.1 dB
Attainable Net Data Rate: 12.727 Mbps 57.354 Mbps
============================================================================
VDSL Band Status U0 U1 U2 U3 D1 D2 D3
Line Attenuation(dB): 6.9 29.0 42.8 N/A 14.0 34.4 55.1
Signal Attenuation(dB): 6.9 28.6 42.6 N/A 17.2 34.1 55.1
SNR Margin(dB): 8.6 8.5 8.5 N/A 13.5 13.5 13.6
Transmit Power(dBm):- 0.1 -14.0 6.6 N/A 11.4 7.8 5.5
============================================================================

VDSL Counters

Downstream Upstream
Since Link time = 56 min 59 sec
FEC:   9190   144
CRC:   0   44
ES:   0   38
SES:   0   0
UAS:   0   0
LOS:   0   0
LOF:   0   0
LOM:   0   0
Latest 15 minutes time = 10 min 2 sec
FEC:   33   1
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:   32   1
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 = 10 hours 25 min 2 sec
FEC:   2680   66
CRC:   0   20
ES:   0   18
SES:   0   0
UAS:   0   0
LOS:   0   0
LOF:   0   0
LOM:   0   0
Previous 1 day time = 24 hours 0 sec
FEC:   10606   413
CRC:   1163   98
ES:   21   88
SES:   20   0
UAS:   78   58
LOS:   1   0
LOF:   7   0
LOM:   0   0
Total time = 1 days 10 hours 25 min 2 sec
FEC:   13286   479
CRC:   1163   118
ES:   21   106
SES:   20   0
UAS:   78   58
LOS:   1   0
LOF:   7   0
LOM:   0   0
============================================================================

[licquorice]

Yep, looks like you have been banded. If you are on a 40M service anyway you won't tell the difference.

[Tacitus]

Yep, looks like you have been banded. If you are on a 40M service anyway you won't tell the difference.

Thanks for the reply.  I agree that in practical terms there is little to no difference but I'm curious.  Sorry for all the questions but my technical knowledge of VDSL/Fibre and the machinations of OpenReach is limited.   

Which of the figures tells you that I'm on banding?

What are the implications?  Will this be removed in time or am I stuck with it?  Are there several banded profiles going down to (say) 5Mbps as the line deteriorates further?

Why does the maximum attainable stay more or less the same, whilst the sync speed goes down?  Surely if the problem is noise/errors etc the max attainable should go down as well.

Thanks for any help.

[licquorice]

The actual data rate of an exact figure (well 34.999) of one of the band boundaries rather than a random figure is the clue. See https://community.plus.net/t5/Library/FTTC-DLM-What-it-is-How-it-works/ba-p/1322799 for the band profiles. If whatever caused the problem has now gone away, your line should eventually recover to its previous figure although DLM doesn't always relent and remove banding.

[Tacitus]

The actual data rate of an exact figure (well 34.999) of one of the band boundaries rather than a random figure is the clue. See https://community.plus.net/t5/Library/FTTC-DLM-What-it-is-How-it-works/ba-p/1322799 for the band profiles. If whatever caused the problem has now gone away, your line should eventually recover to its previous figure although DLM doesn't always relent and remove banding.

Useful link thanks.  Does DLM apply interleaving as well as banding and how do I tell?  IE both at the same time or is it one or the other.

[licquorice]

DLM applies Interleaving and G.Inp as well as banding. Banding is a last resort and only usually happens after a severe burst of disturbance. Have a look at http://dslstats.me.uk/index.html to obtain extra stats and graphs from your router as the stats you have posted show G.Inp but not Interleaving depth.

[ejs]

The DLM applies retransmission (G.INP) or interleaving.

The minor levels of interleaving/FEC associated with retransmission on Huawei cabinets are not particularly significant. Retransmission requires maintaining a queue of data in memory, as does interleaving, equipment can't do significant levels of interleaving and retransmission at the same time.

[Tacitus]

Have a look at http://dslstats.me.uk/index.html to obtain extra stats and graphs from your router as the stats you have posted show G.Inp but not Interleaving depth.

I shall have to fire up the Windows machine to use that as I'm Mac based.  For some reason I can't login via telnet otherwise I could use 'show VDSL' which I think is the correct command.

[licquorice]

If you do manage to telnet in, at the ATP> prompt type sh for a shell. At the shell prompt the command is xdslcmd info --show  I think the interleave depth is the Bearer0 D: figure, but I'm sure somebody will correct me if I'm wrong.

[Tacitus]

If you do manage to telnet in, at the ATP> prompt type sh for a shell. At the shell prompt the command is xdslcmd info --show  I think the interleave depth is the Bearer0 D: figure, but I'm sure somebody will correct me if I'm wrong.

Thanks.  I've managed to get so far in and it's obviously connected to the Zyxel, but it accepts the username and simply locks up when I try to put in the password.  I've looked at the admin stuff via the browser and can't see any reason why it should reject access via telnet.

Shame as telnet has been quite useful with routers in the past.

I have got an old Windows box running XP (it's that old) so I might dig it out just for this unless DSLStats is Win7 and up.  If that's the case I'm stuffed.

[roseway]

You didn't say what model of Zyxel it is, but any models with recent firmware only permit a single telnet access at any one time. Is it possible that you have some other device connecting by telnet, or maybe a zombie access which didn't clear properly? These things aside, there is normally no problem accessing the data by telnet. The advice given above isn't correct for Zyxel - it applies to the HG612. With the Zyxels you should only need to enter name and password to gain access to the CLI. The command to get the main stats is

Code: [Select]

adsl info --stats
or
xdslctl info --stats

[Tacitus]

You didn't say what model of Zyxel it is, but any models with recent firmware only permit a single telnet access at any one time. Is it possible that you have some other device connecting by telnet, or maybe a zombie access which didn't clear properly? These things aside, there is normally no problem accessing the data by telnet. The advice given above isn't correct for Zyxel - it applies to the HG612. With the Zyxels you should only need to enter name and password to gain access to the CLI. The command to get the main stats is

Code: [Select]

adsl info --stats
or
xdslctl info --stats

Unlikely I have any other telnet instances since the router (Zyxel SBG 3300) is locked to one IP address for admin purposes.  Nonetheless I went through the list of processes and can't find any.  I think the problem might be computer related although I can't fathom why.  This is what I get after logging into the shell as admin:

Trying 10.0.1.0...
Connected to 10.0.1.0.
Escape character is '^]'.

ZyXEL SBG3300
Login: ****
Password:   

Then it refuses to accept any further input, but eventually produces the following:

telnetd:error:59.557:lck_checkBeforeEntry:171:lock required during cmsObj_get
telnetd:error:59.558:rut_isAdvancedAccountSecurity:1589:get of LOGIN_CFG failed, ret=9807
telnetd:error:59.559:lck_checkBeforeEntry:171:lock required during cmsObj_getNextInSubTreeFlags

No idea whether these are MacOS or Zyxel error codes - a quick Google didn't produce anything meaningful.  Used telnet in the past with both Draytek and Zyxel routers with absolutely no problem.

[WWWombat]

telnetd:error:59.557:lck_checkBeforeEntry:171:lock required during cmsObj_get
telnetd:error:59.558:rut_isAdvancedAccountSecurity:1589:get of LOGIN_CFG failed, ret=9807
telnetd:error:59.559:lck_checkBeforeEntry:171:lock required during cmsObj_getNextInSubTreeFlags

'telnetd' is likely to be the server (daemon) process on the ZyXel, rather than the client on the Mac.

[roseway]

I'm not familiar with this model, but is there a particular reason why you're using the IP address 10.0.1.0? The default IP address is 192.168.1.1, and the login name and password are the usual admin and 1234. 10.0.1.0 may have different login credentials. If I'm talking through my hat then please tell me to go away.

[Tacitus]

I'm not familiar with this model, but is there a particular reason why you're using the IP address 10.0.1.0? The default IP address is 192.168.1.1, and the login name and password are the usual admin and 1234. 10.0.1.0 may have different login credentials. If I'm talking through my hat then please tell me to go away.

Once I'd done the initial login with admin/1234 etc I decided to alter it to 10.0.1.0 as that's the LAN my other stuff was on.  I think using that range also stems from the days when I regularly used a VPN to login to home and the need for both ends to be on different ranges.  OK there are other ways but that's the choice I made at the time.

Don't think that's the problem but I've not previously tried using telnet with this router.  It worked OK with previous ones, but it's an interesting point.

Easier to continue than to alter everything else as some things are on fixed IP with the DHCP element on a higher range.  EG DHCP starts at 10.0.1.50 some other things are on fixed but below that range.  OK the DHCP elements are effectively fixed since I do MAC binding, but still.

TBH I think it might be a good idea to start again with a more logical setup based entirely on DHCP and MAC binding. When this router bails out, I'll probably do that