In reply to a post by funchnugget:

Channel Status	Upstream	Downstream
Actual Net Data Rate	6916000 kbps	33112000 kbps
Actual Interleave Delay	0 ms	975 ms
Actual INP	0 Symbols	30 Symbols
Attainable Net Data Rate	6905000 kbps	38260288 kbps
Transmit Power	117 dBm	49 dBm

I haven't seen any ECI output before, only stuff from the Huawei. Your output numbers look a little strange, so this will take a little guesswork.

First, it looks like DLM has intervened on your downstream: non-zero values for delay and INP indicate this.

"Delay" is the maximum amount of additional latency that DLM is allowing the modems to add for interleaving. "INP" stands for "impulse noise correction", and indicates the maximum length of noise bursts that the modem's error correction procedure has to cope with.

On the Huawei, the standard "first choice" of delay is 8ms, while the standard choice of INP is 3 symbols.

For the ECI, we should assume that the delay isn't really 975ms; a value of 9.75ms seems a better bet. The INP probably isn't 30 symbols, so perhaps it means 3.0 symbols.

Taken together, if I'm right, then DLM has intervened to cope with errors, and found that it has had to adjust on at least one occasion.

That will probably explain why you have less speed now than when you first posted. And because your line looks to have a maximum attainable of 38Mbps, it looks like the result from the 80/20 upgrade was correct - it happened, but your line couldn't cope with more. I'm sure the regrade happened, at least partially, because you saw your BT IP profile upstream value set to 20Mbps.

However, one thing looks a little suspect: The TX Power. Your values are probably best read as 11.7dBm upstream and 4.9 dBm downstream.

On my current line, the equivalent numbers read as 7.0 dBm upstream and 13.1dBm downstream.

My figures are the other way around in magnitude (downstream larger than upstream), and both are larger.

Perhaps this is a real issue, or perhaps the line is working fine and your display is confused (eg displaying figures the wrong way around). This happens on the Huawei, where the GUI mixes up data compared to the command-line.

Current 15 mins Near End Far End
CRC 0 0
FEC 5139 0
ES 0 0
SES 0 0
UAS 32 0

The fact you are seeing FEC errors indicates that the FEC process has been turned on, confirming that DLM has been triggered.

Over 5,000 errors (even though corrected) sounds like a fairly high number for 15 minutes of operation, but it would map to a smaller number of CRC errors if FEC were turned off.

But right now you are getting zero CRC errors, which means FEC is catching everything. With figures like that, DLM wouldn't want to slow you down more.

Looks like my downstream IP profile has dropped again (33.73 to 32.05) - looks like the brief power outage as I swapped modems was enough to knock it down

It is probably just the fact that you re-synced it at the worst time of day. Choose to re-sync mid-morning, and things will likely improve.