Strange TalkTalk Fibre Issue

I'm currently on Fibre Large but only able to get around 40mbps and i've been on fibre for about a week now.
TalkTalk sent one of their Huawei SuperRouters and it was a self install with no engineer visit and there is no OpenReach modem.

I was doing a "chat" with a TalkTalk rep as i said the line wasn't getting the Fibre Large speeds and they've said there is a fault on the line.
My wiring in the house is pretty straight forward and the cable comes in and goes straight to the NTE with no extensions.

The TalkTalk rep said there was a fault and said and i quote "there appears to be a fault with the battery in the DSLAM".

Any thoughts from people in "the know"?

A fault with the battery backup in the DSLAM won't affect sync speed.

A battery contact between the two wires of your phone line may be causing problems. What was the sales estimate given to you when you signed up

well, here's the thing

The sales rubbish says "39 Mbps - 40 Mbps"
The Wholesale Checker says 80Mbps which i posted about and you and i both exchanged emails and identified a fault with the checker.

However they let me order fibre large and are convinced i should be able to go faster (which will be based on the wholesale checker).

Either way they've still identified a fault on the line but i was somewhat sceptical when they went on about the battery!

I seem to be on an interleaved profile at the moment even though the first sync on Fibre was on the Fast profile so i guess DLM is all over my line at the moment. From what i can see on the TalkTalk Router (which is limited information) the line was stable and i'm not getting drop outs and couldn't see a load of errors!

What is your upstream sync right now? This will tell you whether it is line conditions or an incorrect profile with Talktalk (the 40mbit product is capped at 2mbit upstream).

If it is indeed the profile, then as a self install will likely have been initially configured as a 40mbit connection and then regraded - thats how mine worked. I found that i was stuck on the 40/2 profile with Talktalk post regrade until i turned off my router and left it switched off for a good hour or so before restarting it. This was something to do with the profile settings being carried within the DHCP service which needs to cycle and re-issue.

I am not sure technically beyond this, but that was certainly the case for me with TT Fibre Large. This obviously assumes that actually you are graded correctly at talktalks end.

The term 'battery fault' usually applies to an underground problem with your line. Your pair is picking up the voltage from another working circuit(s).There is a fair chance if you do have a battery contact fault that it is affecting sync rates.

However, if when you spoke with TT and the recorded a battery fault on the remote line test why have they not reported it to Openreach for repair ?

I believe they are in the process of escalating and asked me a bunch of questions about availability for an engineer should one be required to visit.

re: sync rate now.
I don't know as i'm at work but when i get home i'll let you know! I seem to recall the upstream being around 8-10mb!

overall the downstream sync speed has dropped 4mbps since it first sync'd.

Something i've noticed on the TalkTalk router is that is has a max sync rate (up & down) and sync rate (up & down) so i'm not actually sure what the difference is between the two other than there being a difference!

I'm also plugged directly into the master socket not that i would think that makes much difference tbh as i don't have any wired extensions off the NTE.

Post the figures from the router for the max sync rate and sync rate.

Here are the stats as of right now!

DSL synchronization status:
Up
Connection status:
Showtime
Upstream line rate (kbit/s):
9180
Downstream line rate (kbit/s):
33947
Maximum upstream rate (kbit/s):
8893
Maximum downstream rate (kbit/s):
44860
Upstream noise safety coefficient (dB):
4.4
Downstream noise safety coefficient (dB):
4.6
Upstream interleave depth:
1
Downstream interleave depth:
1967
Line standard:
VDSL2
Upstream line attenuation (dB):
8.1
Downstream line attenuation (dB):
19.5
Upstream output power (dBm):
2.6
Downstream output power (dBm):
9.9
Channel type:
Interleaved
DSL up-time:


TalkTalk came back to me and seem to think the issue is resolved.

I do have a Billion 8800NL and a Openreach Mk3 faceplate which i had ordered anyway. Is it woth continuing with the setup for that?

I decided to connect the Billion 8800NL and the MK3 faceplate anyways and here are the current line stats

xDSL
Mode VDSL2
Traffic Type PTM
Status Up
Link Power State L0

Downstream Upstream
Line Coding (Trellis) On On
SNR Margin (dB) 6.2 6.1
Attenuation (dB) 24.0 0.0
Output Power (dBm) 12.9 3.0
Attainable Rate (Kbps) 42707 8454

Rate (Kbps) 35779 8454

B (# of bytes in Mux Data Frame) 51 239
M (# of Mux Data Frames in an RS codeword) 1 1
T (# of Mux Data Frames in an OH sub-frame) 64 45
R (# of redundancy bytes in the RS codeword) 12 0
S (# of data symbols over which the RS code word spans) 0.0462 0.9023
L (# of bits transmitted in each data symbol) 11072 2128
D (interleaver depth) 701 1
I (interleaver block size in bytes) 64 120
N (RS codeword size) 64 240
Delay (msec) 8 0
INP (DMT symbol) 3.00 0.00

OH Frames 13943325 4042275
OH Frame Errors 99 88
RS Words 3569406000 3279593
RS Correctable Errors 896448 0
RS Uncorrectable Errors 2709 0

HEC Errors 594 0
OCD Errors 0 0
LCD Errors 0 0
Total Cells 2850444111 0
Data Cells 117161335 0
Bit Errors 0 0

Total ES 29 60
Total SES 0 0
Total UAS 31 31

There's something of a jump in attenuation from the TT modem to the Billion - 20dB to 24dB. That can happen between modems with different chipsets. I'm not sure what is in the TT modem.

The Billion normally produces attenuation figures comparable to the HG612, with the same family of Broadcom chip set. A value of 24dB probably equates to a distance of 600m of standard 0.5mm copper; speeds of 80/20 aren't likely there. Something like 50/12 seems more likely.

Otherwise, DLM has intervened, so is eating a chunk of bandwidth, and adding 8ms latency.