FTTC Retransmission Low/High Question

Hey all

My line is currently shows:

Bearer 0
INP: 54.00 0.00
INPRein: 1.00 0.00

Which means retransmission is set to high for the downstream.

Will this automatically change to retransmissions low if the line becomes stable by itself? Does the DLM take care of changing this?

It *ought to* …….,

In reply to a post by Zarjaz:

It *ought to* …….,

How long does it usually take? (Just based on average)

Also the DLM takes care of the retransmission low/high right?

That I could not reliably answer. Witchunt would be my best guess as the poster with the answers.

In reply to a post by Zarjaz:

That I could not reliably answer. Witchunt would be my best guess as the poster with the answers.

I'd be happy with an unreliable answer but hopefully it's your best calculated guess type of answer.

Maybe quite soon, sometime or possibly never! Nobody knows. I had re-transmission high on my line for no apparent reason. Full sync speed and virtually no errors.

I tried a suggested method that can remove it by capping my sync speed to a lower value, I think I set it to 60Mbps. You need a Broadcom based modem ( I use an unlocked Huawei HG612 ) The command is "xdslcmd configure --maxDataRate" followed by values for downstream and upstream
Can't recall the exact format but a bit of searching should find it. Try the Kitz forum.

Anyway after a week or so there was a local power cut and when the modem came back up the line was at full sync speed with re-transmission low, so it worked for me.

My trusty HG612 will be retired soon, I have an FTTP order in progress, delayed by a blocked duct in the pavement. Openreach taking their time to fix it.

It relies on many different factors, and even then, can sometimes not readjust under its own steam.

In reply to a post by Realalemadrid:

Maybe quite soon, sometime or possibly never! Nobody knows. I had re-transmission high on my line for no apparent reason. Full sync speed and virtually no errors.

I tried a suggested method that can remove it by capping my sync speed to a lower value, I think I set it to 60Mbps. You need a Broadcom based modem ( I use an unlocked Huawei HG612 ) The command is "xdslcmd configure --maxDataRate" followed by values for downstream and upstream
Can't recall the exact format but a bit of searching should find it. Try the Kitz forum.

Anyway after a week or so there was a local power cut and when the modem came back up the line was at full sync speed with re-transmission low, so it worked for me.

My trusty HG612 will be retired soon, I have an FTTP order in progress, delayed by a blocked duct in the pavement. Openreach taking their time to fix it.

I remember capping my speeds last time. Only problem with this is that the retransmission high will very likely come back once uncapped (if it detects too many errors) ... I'd just want to leave it natural in the way it goes about doing things.

I must have a very clean line with very few downstream errors, in fact since my last sync event over 17 days ago my stats show zero for CRC, ES and SES errors. I capped my line 5 years ago and it has stayed on retx low ever since.

Best of luck waiting for DLM to remove retx high.

Best of luck waiting for DLM to remove retx high. (I bet DLM will never get it removed it off) EVIL DLM!

Edited by adslmax (Fri 09-May-25 16:10:36)

I have the same on my DSLStats reported clean bill of zero CRC, SES, ES and DLM put High Retransmission (downstream) is so ridiculous because it will reduced your throughput speed 8/9% loss. I do hate the EVIL DLM. Been on it for over 10 days now, no sign of DLM removed it off yet.

Downstream Upstream
Line attenuation (dB): 11.8 0.0
Signal attenuation (dB): Not available on VDSL2
Connection speed (kbps): 79970 19999
SNR margin (dB): 4.4 15.2
Power (dBm): 12.4 0.1
Interleave depth: 8 1
INP: 52.00 0
G.INP: Enabled Not enabled
Vectoring status: 5 (VECT_UNCONFIGURED)

Bearer 0
RxQueue 124 0
TxQueue 31 0
G.INP Framing 18 0
G.INP Lookback 31 0
RRC Bits 0 24
Interleave depth 8 1
INP 52.00 0.00
INPRein 1.00 0.00
Delay 0 0
Bearer 1
Interleave depth 3 0
INP 4.00 0.00
INPRein 4.00 0.00
Delay 3 0

I did ask Martin (Aquiss) for DLM resetted as he will ask BTw to get it DLM resetted as per my request buit nothing is done yet by BTw is rather annoying.

I don't understand why DLM actioned to put high retransmission on downstream even no errors on CRC, SEC, ES should never put high retransmission on it. Possible bug on DLM system (Openreach)

Edited by adslmax (Fri 09-May-25 18:02:09)

You need a Putty Telnet tool

Cap at 60Mb. Leave for 8-11 days.
Should hopefully go Retx Low.

Sync will be similar but throughput better.

It might even change within a couple days. Every line is different.

adsl configure --maxDataRate 60000 20000 100000

Just done mine have to wait for next few days to see if DLM removed high retx
https://i.ibb.co/zhXt8SV5/Capped-Line-60000-Kbps-to-...

Downstream Upstream
Line attenuation (dB): 11.9 0.0
Signal attenuation (dB): Not available on VDSL2
Connection speed (kbps): 60000 19999
SNR margin (dB): 9.9 15.5
Power (dBm): 12.4 0.8
Interleave depth: 8 1
INP: 52.00 0
G.INP: Enabled Not enabled
Vectoring status: 5 (VECT_UNCONFIGURED)

Bearer 0
RxQueue 136 0
TxQueue 34 0
G.INP Framing 18 0
G.INP Lookback 31 0
RRC Bits 0 24
Interleave depth 8 1
INP 52.00 0.00
INPRein 1.00 0.00
Delay 0 0
Bearer 1
Interleave depth 1 0
INP 2.00 0.00
INPRein 2.00 0.00
Delay 0 0

Edited by adslmax (Fri 09-May-25 17:59:51)

In reply to a post by adslmax:

You need a Putty Telnet tool

Cap at 60Mb. Leave for 8-11 days.
Should hopefully go Retx Low.

Sync will be similar but throughput better.

It might even change within a couple days. Every line is different.

adsl configure --maxDataRate 60000 20000 100000

Just done mine have to wait for next few days to see if DLM removed high retx
https://i.ibb.co/zhXt8SV5/Capped-Line-60000-Kbps-to-...

Downstream Upstream
Line attenuation (dB): 11.9 0.0
Signal attenuation (dB): Not available on VDSL2
Connection speed (kbps): 60000 19999
SNR margin (dB): 9.9 15.5
Power (dBm): 12.4 0.8
Interleave depth: 8 1
INP: 52.00 0
G.INP: Enabled Not enabled
Vectoring status: 5 (VECT_UNCONFIGURED)

Bearer 0
RxQueue 136 0
TxQueue 34 0
G.INP Framing 18 0
G.INP Lookback 31 0
RRC Bits 0 24
Interleave depth 8 1
INP 52.00 0.00
INPRein 1.00 0.00
Delay 0 0
Bearer 1
Interleave depth 1 0
INP 2.00 0.00
INPRein 2.00 0.00
Delay 0 0

I've set a limit before but don't like the idea that it could go back to Retransmission high when the line gets uncapped.

Let me wait a couple of days then will decide on next steps.

DLM has resync this morning after 4am. Went back to the same as before as DLM refused to removed retx high INP 1.0. Throughput still 9% reduced. https://www.speedtest.net/result/17718430535

Also did noticed Last Retrain Reason: 1 (what this code mean?)

Downstream Upstream
Line attenuation (dB): 11.9 0.0
Signal attenuation (dB): Not available on VDSL2
Connection speed (kbps): 79999 19999
SNR margin (dB): 4.3 15.5
Power (dBm): 12.4 0.5
Interleave depth: 8 1
INP: 52.00 0
G.INP: Enabled Not enabled
Vectoring status: 5 (VECT_UNCONFIGURED)

Bearer 0
RxQueue 136 0
TxQueue 34 0
G.INP Framing 18 0
G.INP Lookback 31 0
RRC Bits 0 24
Interleave depth 8 1
INP 52.00 0.00
INPRein 1.00 0.00
Delay 0 0
Bearer 1
Interleave depth 3 0
INP 4.00 0.00
INPRein 4.00 0.00
Delay 3 0

adsl info --stats
adsl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason: 1
Last initialization procedure status: 0
Max: Upstream rate = 25520 Kbps, Downstream rate = 86955 Kbps
Bearer: 0, Upstream rate = 19999 Kbps, Downstream rate = 79999 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): 4.3 15.5
Attn(dB): 11.9 0.0
Pwr(dBm): 12.4 0.5

Bearer 0
INP: 52.00 0.00
INPRein: 1.00 0.00
delay: 0 0
PER: 0.00 3.98
OR: 0.01 64.22
AgR: 80244.76 20063.54

Bearer 1
INP: 4.00 0.00
INPRein: 4.00 0.00
delay: 3 0
PER: 16.06 0.01
OR: 95.62 0.01
AgR: 95.62 0.01

Bitswap: 976/976 2/2

Since Link time = 4 hours 55 min 7 sec
FEC: 192 29
CRC: 0 15
ES: 0 15
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0

Edited by adslmax (Sun 11-May-25 08:44:38)

DLM has actioned last night after 1am

My line is currently shows:

Bearer 0
INP: 48.00 0.00
INPRein: 0.00 0.00

Retransmission is set to OFF for the downstream.

Downstream Upstream
Line attenuation (dB): 11.9 0.0
Signal attenuation (dB): Not available on VDSL2
Connection speed (kbps): 79999 19999
SNR margin (dB): 4.0 15.4
Power (dBm): 12.4 0.1
Interleave depth: 16 1
INP: 48.00 0
G.INP: Enabled Not enabled
Vectoring status: 5 (VECT_UNCONFIGURED)

Throughput speed now 74.8Mbps (back to normal range)