Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[GunJack]

Ey up guys, not been around here for a while, but would like to pick your brains on some stuff pleezzze 

This may ramble a bit, so please bear with it....

Right, I went FTTC a while back (stayed with TT) on the 38/2 package, with a HG635. All good, 14dB down, 25dB up attenuation, synced at 38 down 2 up, 6dB snrm both ways and on fastpath. Router GUI showed max attainable rates of 20 up and 82 down

Around 6 months back, moved to 76/20 package, synced at 20up and 72 down, fastpath, 6dB snrms again. GUI showing max attainable of circa 18-19 up, 76 down. Good so far...

Over the last few months though, max attainable has dropped to 65 down, and sync to around 56 down. Now I know crosstalk can affect VDSL speeds, but this much??

Anyhow, TT have sent me a HG633 to try, and as of this morning with the 633, I'm getting 14dB down/0.1db up attenuation (I'm assuming the 0.1 is a fw bug on upstream attenuation), max attainable has risen to 74 but sync still at 56 and upstream within a meg of previous figures. However, I unplugged old router and straight away connected new one, which is why (I'm assuming) interleaving has been activated - 1 up and 2800-odd down (boo hiss).

I'm assuming DLM has been triggered for the interleaving issue (how long would this typically take to settle and go back to fastpath?), but what about the sync speed?? Any suggestions/observations/other points would be welcomed... TIA

[ejs]

Yes, I expect crosstalk could affect your speed that much.

I would not expect the DLM to be adversely affected by one single modem switch in a day, even without a sufficient gap before connecting the new one.

I think an interleaving depth of around 2800 is a very high value (the maximum interleaving depth for profile 17a being 3072), so I doubt it will be going away on it's own any time soon.

[GunJack]

Yes, I expect crosstalk could affect your speed that much.

I would not expect the DLM to be adversely affected by one single modem switch in a day, even without a sufficient gap before connecting the new one.

I think an interleaving depth of around 2800 is a very high value (the maximum interleaving depth for profile 17a being 3072), so I doubt it will be going away on it's own any time soon.

Interesting.... the question is, then, why has interleaving suddenly kicked in??

[Sheepie]

in the last 2 months I have switched off or rebooted the modem 6 times myself, and 5 out of those 6 times the next morning (about 6am) the DLM has increased INP (and therefore interleaving and delay). This happened even with leaving the modem off for 30 mins.
The only time the DLM did not do anything the next morning was when I was already banded and with high interleave both US & DS.

If you do need to change modem then leave the new modem sync'ed up until your interleave is back to what it was before. For me it seems to take 9 days to get back to normal after a single modem resync

[GunJack]

it seems to take 9 days to get back to normal after a single modem resync

AArrgghhh!!! 9 days     

[GunJack]

"Yes, I expect crosstalk could affect your speed that much."

15-17 megs?? really?? Is this something that vectoring may help with, or has all that gone away now ??

[j0hn]

I've seen crosstalk be considerably worse than that.
It's likely the interleaving was applied some time ago, using the previous modem.
Before switching modem your line had max attainable 65 down, and sync 56 down. That's either a banded downstream, interleaving+FEC, or incorrect stats.

Can you access the telnet stats on the HG635? It's the only compatible Talktalk modem that I'm aware of that works with DSLStats/MyDSLWebStats.
To get the best advise on your line I would recommend going back to the HG635 and uploading the stats to MDWS.
There's only so much that can be done with the stats from the GUI, which often have errors in them.

[les-70]

  If you don't currently have telnet access to your HG635 the best way to get it is in

http://forum.kitz.co.uk/index.php/topic,15574.msg289830.html#msg289830

[adamcuk]

Hi,

I have been on the 80/20 package with talktalk for a while now too and had stats that were virtually identical to yours. 

It may be worth checking your firmware on the HG633, i think it ships with version 1.15t. I asked for an upgrade to 1.21t and almost overnight my speeds went from 56/17 to 69/20 and interleaving dropped from 2700 to 5. Its been quite stable at that for a while too. 

I have heard of people having issues with the 1.21t firmware but its been great for me.  You need to request it on the community forum though, if you ask over the phone they will put you on 1.20t which doesnt work so well with fibre.

[GunJack]

Yeah, mine shipped with 1.15 and updated overnight to 1.21. No difference in speeds yet, but d/s interleaving dropped from 2700-odd to 2100-odd.... will prob have to wait now for DLM to sort itself out 

[GunJack]

  If you don't currently have telnet access to your HG635 the best way to get it is in

http://forum.kitz.co.uk/index.php/topic,15574.msg289830.html#msg289830

OOhh, could be playtime over xmas... haven't done anything like this for a while 

[GunJack]

OK, update....

yesterday morning came down to find no authentication, but with VDSL on the line

Thankfully TT have sorted this out in a little over 24 hours, so fair play to them

However, stats now worst they've been ever on FTTC, just got to wait now for DLM to sort out the connection, and if not done within 2 weeks, that'll be another call to TT

Do TT (or any other provider for that matter) have enough access to OR to initiate a line re-train themselves, or will they have to request it from OR?

[burakkucat]

A dropped PPPoE session that fails to re-establish is a problem in the CPs/ISPs domain. Any corrective action that the CP/ISP takes should not involve the physical infrastructure and the synchronisation status between the modem - MSAN (DSLAM).

A "circuit recalc" (using Openreach technician terminology) or a DLM reset can only be performed by Openreach. It is supposed to be performed only when a physical defect in the metallic pathway has been rectified. It would be initiated from either the technician's mobile phone or laptop computer.

[GunJack]

thanks b*cat for the clarification   Not used to this new-fangled fibre and being back through ISP and OR stuff, was too settled previously on LLU. Looks like I still need to wait for DLM to restore speed, latest resync following the fault is down at 42 meg, at 8.8dB snrm and high (2800-odd) interleaving   How's you doing??

[burakkucat]

. . . latest resync following the fault is down at 42 meg, at 8.8dB snrm and high (2800-odd) interleaving  

It certainly looks as if there is the potential for a higher synchronisation speed with (what seems to be) that 9 dB SNRM target. Have we established with which type of DSLAM your serving "fibre" cabinet is quipped? If it's Huawei equipped then, given time, G.Inp should be enabled for your circuit.

How's you doing??

Not too bad, thank you. (The older kittehs become, the more grumpier their day.)