Is this article correct still http://www.thinkbroadband.com/news/5929-reminder-abo... or has the way it works changed?
No. That article dates back to before BT rolled out G.INP support in any form.
Nowadays, most lines from a Huawei cabinet will have downstream set to "retransmission low" and upstream set to "error protection off".
What happens when DLM is reset is somewhat ambiguous. Some evidence suggests the initial setting turns error protection off in both directions, as used to be the case. However, we have been told that a DLM reset should now set downstream "interleaving low" as the initial option (upstream off), before changing downstream to "retransmission low" when it recognises the modem as capable.
It isn't clear whether that behaviour for a DLM reset should only apply to Huawei cabinets.
More information available here:
I'm told my profile is "0.128M-80M Downstream, Retransmission Low - 0.128M-20M Upstream, Error Protection Off" and syncing at 61mbps.
Can retransmission be set to off?
Yes. It is off in the upstream direction, and DLM can choose to turn it off in the downstream direction.
What is involved when BT engineer does a DLM profile reset.... I'm guessing its a 5 minute job once at the exchange?
No visit is required. DLM resets are triggered from an Openreach operations centre (somewhere in Bristol?), upon request from an engineer. Engineers aren't free to request a DLM reset willy-nilly; they need to be able to justify it - for example, by fixing a physical fault with the line.
Can G.INP be disabled on lines? Reason i ask is i used to sync at 80mbps until the day G.INP was added to my line (I had ECI modem on huawei cab...but now i have huawei modem and even changed ISP and my speed has never improved)
No it cannot be disabled - DLM cannot be told to never use it as an option.
Is your Huawei unlocked? If so, what firmware version is it using? It needs to be an updated version in order to support G.INP.
If it is unlocked, can you provide a copy of the line stats?