So I have some interesting observations to report.
I have done some fiddling around with the modem and router settings to see if anything will make a difference. The only major tweaks were I disabled NAT acceleration, and moved the job of tagging traffic with VLAN 101 from the modem to the router, I doubt this had any effect. In the process I had to resync the modem, after everything was up and running again I checked the modem stats and they are now:
xdslctl info --stats
xdslctl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason: 0
Last initialization procedure status: 0
Max: Upstream rate = 23354 Kbps, Downstream rate = 69878 Kbps
Bearer: 0, Upstream rate = 20000 Kbps, Downstream rate = 68348 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 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): 3.3 7.7
Attn(dB): 14.9 0.0
Pwr(dBm): 13.9 6.7
VDSL2 framing
Bearer 0
MSGc: -6 20
B: 243 239
M: 1 1
T: 0 64
R: 10 0
S: 0.1137 0.3819
L: 17875 5028
D: 8 1
I: 254 120
N: 254 240
Q: 8 0
V: 0 0
RxQueue: 55 0
TxQueue: 11 0
G.INP Framing: 18 0
G.INP lookback: 11 0
RRC bits: 0 24
Bearer 1
MSGc: 154 -6
B: 0 0
M: 2 0
T: 2 0
R: 16 0
S: 6.4000 0.0000
L: 40 0
D: 3 0
I: 32 0
N: 32 0
Q: 0 0
V: 0 0
RxQueue: 0 0
TxQueue: 0 0
G.INP Framing: 0 0
G.INP lookback: 0 0
RRC bits: 0 0
Counters
Bearer 0
OHF: 0 195601
OHFErr: 0 0
RS: 41849808 12517645
RSCorr: 34 0
RSUnCorr: 0 0
Bearer 1
OHF: 74396 0
OHFErr: 0 0
RS: 743346 0
RSCorr: 0 0
RSUnCorr: 0 0
Retransmit Counters
rtx_tx: 0 0
rtx_c: 0 0
rtx_uc: 0 0
G.INP Counters
LEFTRS: 0 0
minEFTR: 68343 0
errFreeBits: 1245648 0
Bearer 0
HEC: 0 0
OCD: 0 0
LCD: 0 0
Total Cells: 157068087 0
Data Cells: 7325524 0
Drop Cells: 0
Bit Errors: 0 0
Bearer 1
HEC: 0 0
OCD: 0 0
LCD: 0 0
Total Cells: 0 0
Data Cells: 0 0
Drop Cells: 0
Bit Errors: 0 0
ES: 0 0
SES: 0 0
UAS: 23 23
AS: 1195
Bearer 0
INP: 49.00 0.00
INPRein: 0.00 0.00
delay: 0 0
PER: 0.00 6.13
OR: 0.01 33.91
AgR: 68417.78 20033.74
Bearer 1
INP: 4.50 0.00
INPRein: 4.50 0.00
delay: 3 0
PER: 16.06 0.01
OR: 79.68 0.01
AgR: 79.68 0.01
Bitswap: 53/53 1/1
Total time = 20 min 18 sec
FEC: 34 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 23 23
LOS: 0 0
LOF: 0 0
LOM: 0 0
Retr: 0
HostInitRetr: 0
FailedRetr: 0
Latest 15 minutes time = 5 min 18 sec
FEC: 8 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Retr: 0
HostInitRetr: 0
FailedRetr: 0
Previous 15 minutes time = 15 min 0 sec
FEC: 26 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 23 23
LOS: 0 0
LOF: 0 0
LOM: 0 0
Retr: N/A
HostInitRetr: N/A
FailedRetr: N/A
Latest 1 day time = 20 min 18 sec
FEC: 34 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 23 23
LOS: 0 0
LOF: 0 0
LOM: 0 0
Retr: 0
HostInitRetr: 0
FailedRetr: 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
Retr: 0
HostInitRetr: 0
FailedRetr: 0
Since Link time = 19 min 55 sec
FEC: 34 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Retr: 0
HostInitRetr: 0
FailedRetr: 0
NTR: mipsCntAtNtr=0 ncoCntAtNtr=0
The sync speed has changed from 68256Kbps to 68348Kbps, a small increase of 98kbps. I then ran another BT Wholesale speed test, to my surprise the IP profile has changed from 62880kbps to 62970kbps, a small iincrease of 90kbps.
So it appears the IP profile is updating, but not to the expected speed. According to the router stats I appear to be on a ReTx low profile, which should mean the IP profile is 68348 * 0.9669 = 66085Kbps. However it seems to have calculated the new profile as if I am on a ReTx high profile (62970/68348 = 0.9213, about 92.1%).
The only logical explanations I have are:
1. I really am actually on a ReTx high profile.
2. There is a bug going on which is causing an incorrect calculation.
3. The modem is reporting a sync speed higher than the DSLAM, in which case the DSLAM is reporting a sync speed of 62970 / 0.9669 = 65125Kbps. However the BT line checker reports a max observed speed of 68.16Mbps, which is fairly consistent with the sync speed reported by the modem, which makes me doubtful of this possibility.
I feel like I'm stumbling around in the dark with this problem at the moment, Does anyone have any other ideas as to what could be going on?
P.S. Plusnet/Openreach have not come back with any response yet, probably won't get anything until Monday now.