How long for FTTC DLM to improve profile on stable line?

[Ian]

I've made some significant changes to our internal wiring, finally connecting all of the house up with wired ethernet . This means that the router is now plugged in to the master socket and should sync much faster (it should be around 25mbps, based on the last time I tested this).

As the modem is in bridge mode, I'm unable to view the router stats easily - but I can see from my ISP that I'm syncing at 19983Kbps. This looks like it's at the top of the DLM band I'm in (if that's the correct phrasing!).

Does anyone know how long it takes DLM to re-evaluate the line and try to increase the speed? I've had a good Google for this, but there appears to be very mixed answers - although most places seem to suggest 8 days for the first attempt.

 

[V_R]

There is no hard and fast rule I'm afraid Ian. It could be a week or a month, or longer!

Just keep everything on and try not to let it re sync. It will happen in time.

Can you see your max attainable rate?

 

[Ian]

Thanks @V_R, that's what I was worried about . I'll need to find some patience .

I can't easily see the router stats unfortunately, as I would need to re-configure the modem bridge which would involve a reset (which I want to avoid).

Waiting it is then .

 

[V_R]

Ah fair enough, yeah don't upset it as it will just delay the DLM intervention. What are you waiting for? 3dB margin? Do you know what cabinet you're on? Huawei or ECI?

As an example, when I moved into this place it took 7 days exactly for DLM to turn on G.INP on this new line. But it took months for interleaving to be removed after a line fault added it after a storm at my parents house.

There really does not seem to be any pattern to it unfortunately.

This is why I love having a Pie running DSL Stats on my line, I just connect to it via VNC and I can see exactly whats going on. It's powered via the USB socket on the router and uses WiFi so you wouldn't even know its there!

What modem are you using? You could see what an unlocked HG612 is going for on eBay, they may be older but they are still one of the best FTTC modems.

 

[Ian]

Thanks - it does sound like I just need to wait this one out and see what happens over the next month. I did notice my connection reset after midnight and the sync jumped ever so slightly to 20076Kbps.

I'm just waiting for the line to settle at the max speed, as it looks like it's currently profile limited based on the old wiring. With the setup I've got, I can't easily give the modem an IP on our network (I'd need to disconnect it from a Unifi USG, then connect via LAN directly - which drops the connection and would add to DLM recovery time).

It's a Huawei cabinet and I'm using a ZyXEL VMG1312-B10D to connect (a cheap broadcom chipset that apparently works pretty well on long lines with Huawei). Do you think the HG612 would be significantly better? They're pretty cheap on eBay now, but I'm not sure it's worth it unless it gives an extra mbps or two.

It looks like my exchange is being enabled for g.fast, which is interesting... but my line length is too long for it to make a difference .

 

[V_R]

Ah! Didn't realise you had the B10D, they are decent modems. I doubt there will be much, if any difference between that and the HG612 or the A version of yours which is apparently the holy grail, but is also vastly over priced.

You can run DSL Stats with that modem. http://dslstats.me.uk/routers.html

You don't need to run it full time, but you could run it on your laptop/PC to keep an eye on the stats?

 

[Ian]

That's good to know then . I'll stick with the B10D.

Once the line is settled, I'll start tinkering with DSL Stats and get it accessible over the LAN - whatever I do at this point will require a reset and slow DLM normalisation, so I'm chickening out for the moment .

 

[V_R]

Fair play. Lets hope DLM is kind to you!