Clueless clarification - Interleave depth options

In clueless.aa.net.uk, I select a DSL and look at the various line parameters, and in my case I have ADSL2 / BT 21CN lines and I want to adjust the upstream and downstream interleaving depth values. Aside from interleaving on/off, for upstream I have a third option ‘medium’. My question - when you choose an interleaving depth value for upstream say, is ‘medium’ higher or lower interleave depth than just ‘interleave ON’?

What I would like to do - yes, I know I know - is maximise the interleave depth. I’m not concerned about the delay time as I am not a gamer.
This is to get better reliability at all costs and who knows some of that gain might be able to be traded back again in exchange for yet more speed?

Before you ask, you did read correctly. Everyone who talks about interleaving is always wanting to achieve the exact opposite of me: “How can I minimise xxx?” “How can I turn interleaving off ?” “How to force fastpath?” And this regardless of the terrible effects in reliability and sometimes an associated loss of speed in the universal speed-vs-reliability tradeoff.

Edited by CecilWard (Tue 09-Apr-19 09:22:14)

The higher the interleave depth the more stable the line. That’s why Fast Path always has a value of 1, which means no interleaving.

The initial setting is by DLM based on the stability option specified to the wholesaler by AAISP. BTW Wholesale offer three, and IIRC AA default to choosing the highest speed one.

I wouldn’t be surprised if changing it yourself didn’t also change the downstream. I can’t remember what shows up in the radius log.

Edited by RobertoS (Tue 09-Apr-19 09:49:54)

I said it backwards - downstream has three options and upstream is just binary. I don’t know why it’s asymmetric wrt the number of levels.

I just tried changing the _downstream_ to "medium" instead of "on" and forced a resync but I asked the modem and it didn’t change the G.992.3 framing parameters at all. The D (and R) parameters were unchanged, as was pretty much everything else, not just for for downstream but for upstream too.

Downstream can only be altered by DLM, under direct control of BT Wholesale or TalkTalk in the case of AA, depending on the product you are on.

The ISP (AA) can only select one of those three options from their supplier, so with it being downstream the change is indirect. Your change will have triggered a change order to that supplier, which possibly takes a while to be processed.