Slow Downstream FTTC

Hi,

I have been having problems with my FTTC connection for a year or so now. I'm on 80/20
I have an unlocked HG612 for stats
For some reason my DS sync is 34998
However, I have always had a full 20000 US sync
Max attain values are 70340 DS and 23971 US
It seems rather odd that I achieve full US but less than half DS
Is it just me or does it seem out of proportion?

Thanks!

Have seen something similar before - a large block of noise was killing off a significant part of one of teh down stream blocks.

Can you run the graphing package and show what the SNR and bit loading per tone are?

What firmware is on the HG612?

Hi,

Have attached them!

Thanks!

Bitloading

SNR per tone

Hi,

It's on A2pv6C038m.d24j

Thanks

A couple of nasty little notches there around 230, 280, 390.

However, as VDSL2 17a uses tones up to 3970 for down stream, there is a large amount of the graphs missing. Can you get plots right out to 4000?

Edited by MHC (Fri 03-Apr-15 14:36:03)

Sorry about that!
Here are the graphs again!

Thanks,

Bitloading

SNR

Something very odd !

There is obviously a major noise source around tone 300, or something that is killing the signal.

Above that it looks OK - so why?

Can I suggest that you power off, then disconnect everything, wait 30 minutes or so. Power up, let it stabilise then reconnect - using the "test socket" initially and no filter.


Just wondering where about you are and if there is a high power AM radio transmitter close by? That notch is around 1.5 MHz, so a 1548 kHz radio tx could casue it. I see wuit a few on mine at 693, 720, 909, 1215 kHz which nicely align with AM stations.

Edited by MHC (Fri 03-Apr-15 20:14:11)

I'll do a disconnect procedure later on tonight when everyone is asleep!
I'm from Doncaster and as far as I'm aware the nearest transmitter is Emley Moor which is quite far I guess!
Is it worth me digging out an am radio?

Thanks

Right.

I went through to disconnect and reconnect to master test. Unfortunately the cable I had borrowed from the phone seemed to have a different wiring schematic to that of the modem. Therefore I never got it in sync. The wire seems to use 1 + 4 as opposed to 2+ 3

I'll need to source a proper cable!

Just to let you know also I have the MK2 faceplate!

Thanks

You mean a Mk2 interstitial VDSL2 filter plate?

If so, to get to the test socket you have to remove that, not just the NTE5A that houses the external phone socket.

The easiest way to connect then is with an old dangly filter if you have one.

In reply to a post by sammyelrefee:

Right.

I went through to disconnect and reconnect to master test. Unfortunately the cable I had borrowed from the phone seemed to have a different wiring schematic to that of the modem. Therefore I never got it in sync. The wire seems to use 1 + 4 as opposed to 2+ 3

I'll need to source a proper cable!

Just to let you know also I have the MK2 faceplate!

Thanks

I presume you are saying that the cable used had a BT connector at one end and a 4 pin RJ connector that some phones have?

If that is the case, it should not matter as most modems are designed to take either inner or outer pair of an RJ14 6P4C (same shape as RJ11) with 3&4 and 2&5 being the pairs in use. Some are auto and some are manual.

Somewhere in the Telnet Interface it is possible to see which pair is in use and if need be, change it using the command: xdslcmd connection --lpair <i> or <o>

Yep you're correct. I replaced my standard one with the MK2 a while back to see if I could improve things.
I didn't think to use a standard filter to connect my modem at the test socket. That's an idea. I'll try find one of them!

Thanks

Correct.

I had a quick look into the RJ11 port on the modem but there are only 2 pins for 2+3. Because the cable I used was 1+4 it can't make the physical connection. l'll try to find a 'dangly' filter out and connect at the test socket (behind the mk2 of course!)

Thanks

Are you sure it is 2&3? It is 6 pin connector and they should be either 3&4 if only two are provisioned or 2&5 and 3&4 if four have contacts.

Ha got it!
I have never realised rj11 had 6 pinouts. I see that now!
The connector I have has connected live contacts for 2+5
However, the reciprocal plug on the modem has only pins for making contact with 3+4 on the plug.
This therefore made my cable totally useless!!

Sorry for the confusion!

Thanks

Right

I have done the test from the test socket now! I had a look and the bitloading and snr per tone graphs remained constant. Still the v like dip
I'm sure that therefore rules out faceplate issues. Tbh didn't expect a change as I had the same issues with the bitloading graph when I had the original vdsl faceplate on.

Thanks!

Are you SURE that you have not been put on a 40Mbps downstream profile by mistake? I know 40/20 does not exist, however an error could have happened.

At present nothing else actually comes to mind.

And I am scratching my head over my connection too ... A rather large notch causing loss of downstream tones 33-39 and bit loading averaging around 6 all the way up to tone 250 where I start to get 14. If I can sort that, I should be able to get another couple of Mbps!

What about the Hlog and QLN graphs?

Also, can you post the basic text statistics, (eg from the Telnet Data-> Connection Stats tab, and the Telnet Data -> pbParams) as well as the basic information about the cabinet (distances, estimated speeds from BTW, etc).

I'm pretty sure. I had BTOR come round a few times and they reset DLM and just left. It would be ok (ie 75ish) and then decline a few days later. My line has never been the same!
However, I may request another regrade again!

Hi,

Here they are
stats

thanks!

FTTC Range A (Clean)
64.4 45.3
18.5 11.9
FTTC Range B (Impacted)
54.8 30.6
18 7.9

I'm not sure about range from cab as I have been told conflicting info about which cab I'm even connected to! I'm sure I read on a forum somewhere that someone can dig it out!

thanks!

I don't think you've put them in "Public".

The easiest way to post stats is from real telnet. You can just copy and paste from the output.

You need the telnet client enabled in your internet options. Then open a CLI (Command Line Window):-

telnet 192.1.6.1.1
admin
admin
sh
xdslcmd info --show

and for the pbParams, the same but with the last line replaced by:-

xdslcmd info --pbParams

In reply to a post by MHC:

Are you SURE that you have not been put on a 40Mbps downstream profile by mistake? I know 40/20 does not exist, however an error could have happened.

It does on Plusnet, by providing 80/20 and capping the 80 internally.

If the OP is on Plusnet, (even if from a few years back), then that cap may have been wrongly applied.

There is also the possibility, (not having looked at the previous links), that the line has been capped by the DLM for some reason.

on TT
I appear to be banded in the 17.5 to 35 dlm profile.

thanks

Hi

How strange the link works for me not logged in. Although it did ask me to sign in clicked x and it downloaded straight away. The link has the QLN and Hlog

Pbparams
xdslcmd info --pbParams
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Last initialization procedure status: 0
Max: Upstream rate = 24267 Kbps, Downstream rate = 70400 Kbps
Bearer: 0, Upstream rate = 20000 Kbps, Downstream rate = 34998 Kbps

Discovery Phase (Initial) Band Plan
US: (6,31) (882,1193) (1984,2770)
DS: (33,857) (1218,1959) (2795,4083)
Medley Phase (Final) Band Plan
US: (6,31) (882,1193) (1984,2770)
DS: (41,857) (1218,1959) (2795,4083)
VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 24267 kbps 70400 kbps
Actual Aggregate Tx Power: 4.7 dBm 12.6 dBm
====================================================================================
VDSL Band Status U0 U1 U2 U3 U4 D1 D2 D3
Line Attenuation(dB): 0.6 22.9 36.3 N/A N/A 12.4 30.5 49.0
Signal Attenuation(dB): 0.6 22.7 36.2 N/A N/A 17.0 30.3 49.1
SNR Margin(dB): 7.1 6.7 6.8 N/A N/A 14.8 14.8 14.8
TX Power(dBm): -5.1 -23.0 4.2 N/A N/A 9.4 7.2 6.4
#

stats
xdslcmd info --stats
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Last initialization procedure status: 0
Max: Upstream rate = 24267 Kbps, Downstream rate = 70400 Kbps
Bearer: 0, Upstream rate = 20000 Kbps, Downstream rate = 34998 Kbps

Link Power State: L0
Mode: VDSL2 Annex B
VDSL2 Profile: Profile 17a
TPS-TC: PTM Mode(0x0)
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 14.8 6.8
Attn(dB): 17.8 0.0
Pwr(dBm): 12.6 4.7
VDSL2 framing
Bearer 0
MSGc: 36 150
B: 31 236
M: 1 1
T: 64 5
R: 10 16
S: 0.0290 0.3771
L: 11568 5410
D: 1123 1
I: 42 255
N: 42 255
Counters
Bearer 0
OHF: 24114464 64364
OHFErr: 18 11
RS: 669883948 3040757
RSCorr: 987229 155
RSUnCorr: 558 0

Bearer 0
HEC: 82 0
OCD: 5 0
LCD: 5 0
Total Cells: 243986502 0
Data Cells: 35427359 0
Drop Cells: 0
Bit Errors: 0 0

ES: 8 11
SES: 0 0
UAS: 386 386
AS: 67505

Bearer 0
INP: 3.50 0.00
INPRein: 0.00 0.00
delay: 8 0
PER: 2.79 6.15
OR: 120.03 202.87
AgR: 35117.67 20203.27

Bitswap: 43136/43136 49/50

Total time = 18 hours 51 min 31 sec
FEC: 987229 155
CRC: 18 11
ES: 8 11
SES: 0 0
UAS: 386 386
LOS: 0 0
LOF: 0 0
LOM: 0 0
Latest 15 minutes time = 6 min 31 sec
FEC: 7632 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: 18981 4
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 = 18 hours 51 min 31 sec
FEC: 987229 155
CRC: 18 11
ES: 8 11
SES: 0 0
UAS: 386 386
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
Since Link time = 18 hours 45 min 3 sec
FEC: 987229 155
CRC: 18 11
ES: 8 11
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
#

Looks a bit that way.

So DLM has capped your downstream speed due to instability.

In reply to a post by sammyelrefee:

FTTC Range A (Clean)
64.4 45.3
18.5 11.9
FTTC Range B (Impacted)
54.8 30.6
18 7.9

I'm not sure about range from cab as I have been told conflicting info about which cab I'm even connected to! I'm sure I read on a forum somewhere that someone can dig it out!

thanks!

If you got that from the BT Wholesale checker, which it looks like, the line above the table should tell you the cabinet. That's assuming you are using the telephone number or full address options. The Postcode checker cannot be trusted.

In reply to a post by RobertoS:

telnet 192.1.6.1.1

That's a funny looking IP address! Finger slippage, perhaps, Bob?

I run my LAN on IPv4.1

That really is quite messy! I wonder how I did it? Unfortunately 20 minutes too late to edit.

haha!
Didn't even notice that!

I'm served by cab 7 on Cantley exchange (SLCLY)

I see you're on an ECI cabinet.

Correct you are!
Do you have access to some info I don't or did you use maps or something?
all the cabs I have seen in Cantley appear to be ECI.
I have been debating whether to go back to ECI modem and request GEA tests when I want my sync speed lol
Thanks

Edited by deleted (Sun 05-Apr-15 15:14:16)

The band plan you posted is an ECI band plan - DS: (33,857) (1218,1959) (2795,4083)

Edited by deleted (Sun 05-Apr-15 15:09:46)

That's quite clever what you have done there! I like it!