Kitz Forum
Broadband Related => FTTC and FTTP Issues => Topic started by: GunJack on December 17, 2016, 02:32:35 PM
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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 :)
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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.
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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??
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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 :(
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it seems to take 9 days to get back to normal after a single modem resync :(
AArrgghhh!!! 9 days >:( :no:
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"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 ??
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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.
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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
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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.
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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 >:(
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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 ;D
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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?
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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.
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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??
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. . . 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.) ;)
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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.
Not too bad, thank you. (The older kittehs become, the more grumpier their day.) ;)
TBH b*cat, this year hasn't allowed time for techie/broadband/anything, been a bit preoccupied with more important stuff, especially once I went FTTC and the Mini-Guns stopped pestering about "only" having 6meg bb. However, I was synced at 56-57 meg @ 6dB for a good while before the outage, so no reason when everything settles I should get back to at least that.
Is there a lookup site somewhere to check the provenance of my cab, or do I need to pop round and take photos?? If there's a lookup, it's cab 5 on WNWXN exchange :fingers:
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I remember when you found the PCP through which your line is connected . . . it was "embedded" in the hedge at the front of a garden. :)
But having disclosed "it's cab 5 on WNWXN exchange", we can make use of Magneta System's CodeLook service. So this is the first screen (https://www.telecom-tariffs.co.uk/codelook.htm?xid=1786874&cabinets=15521) I examined and it shows --
Cabinet P5 FTTC Available from 26th February 2013 Phase 09a 2012-2013 186 ECI LL11 1AA
We can see the "dreaded" three letters, ECI. So currently no G.998.4 (a.k.a. G.Inp) will be possible for your circuit. Maybe sometime next year . . . :(
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I remember when you found the PCP through which your line is connected . . . it was "embedded" in the hedge at the front of a garden. :)
But having disclosed "it's cab 5 on WNWXN exchange", we can make use of Magneta System's CodeLook service. So this is the first screen (https://www.telecom-tariffs.co.uk/codelook.htm?xid=1786874&cabinets=15521) I examined and it shows --
We can see the "dreaded" three letters, ECI. So currently no G.998.4 (a.k.a. G.Inp) will be possible for your circuit. Maybe sometime next year . . . :(
lol, you remembered!! ;D The MSAN cab is, thankfully, NOT in the hedge, and only about 2 feet away from the PCP. Thanks for the info re: it's an ECI cab... so it's a waiting game :( Any particular chipset routers may be better than the TT-supplied HG635 or 633 for ECI?
Soz for all the questions, told you I was a bit out-of-touch :(
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There are two options --
- Match the DSLAM chipset by choosing Lantiq
- For reliable view-ability of the circuit statistics choose Broadcom
Our leader, Kitz, is connected via an ECI DSLAM but after significant testing has found that the Broadcom based devices are best for her circuit.
Please take a look at the very first post of this thread (http://forum.kitz.co.uk/index.php/topic,14436.0.html) and then I'll suggest that you research the various ZyXEL VMGxxx devices, mentioned at the bottom of the list.
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Thanks b*cat, still a true gent :) Looking at the prices of those routers, think I'll have to stick with the TT-supplied ones for the time being....
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Thanks b*cat, still a true gent :)
:blush:
Looking at the prices of those routers, think I'll have to stick with the TT-supplied ones for the time being....
Yes, they are rather pricey. But I managed to purchase a new, unused ZyXEL VMG1312-B10D for less than £40 . . . and it performs well on my G.992.3 (a.k.a. ADSL2) circuit. A daily scan of eBay can prove to be quite beneficial. ;)
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Thanks b*cat, still a true gent :) Looking at the prices of those routers, think I'll have to stick with the TT-supplied ones for the time being....
You can nab an Eircom F1000 which is a VGM8324. Only problem is you'll have to unbrand it ???
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OK, so after having given the line chance to settle, the current stats are as follows, using the HG633:-
Broadband Information
DSL synchronization status: Up
Connection status: Showtime
Upstream line rate (kbit/s): 17051
Downstream line rate (kbit/s): 54005
Maximum upstream rate (kbit/s): 16979
Maximum downstream rate (kbit/s): 75192
Upstream noise safety coefficient (dB): 6
Downstream noise safety coefficient (dB): 7
Upstream interleave depth: 1
Downstream interleave depth: 2714
Line standard: VDSL2
Upstream line attenuation (dB): 0.1 (must be a fw bug, surely? the HG635 always reported it around 25dB)
Downstream line attenuation (dB): 13.1
Upstream output power (dBm): 6.8
Downstream output power (dBm): 12.2
Channel type: Interleaved
DSL up-time: 16 days 1 hour 20 minutes 40 seconds
considering the interleaving (which was always reported as fastpath on the HG635, with interleaving depths of 0 both up & down) is it worth asking for a line re-train, or is it unlikely to produce better syncs than currently? I don't mind spending half an hour on the phone to TT if it may be worth it..... any opinions welcomed :)
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There's no such thing as a line retrain on FTTC DLM. It's a 100% hands off system. There's absolutely nothing any ISP can do to "tweak" anything on the line.
The only way I know of to help remove interleaving would be using a Broadcom based modem and setting maxdatarate via the telnet interface. Limiting the sync speed to a figure considerably lower than the attainable for around 10 days can push the all important Error Seconds (ES) down low enough for DLM to remove interleaving.
The Huawei HG633 doesn't have this ability, but the Huawei HG635 may. It's the only Talktalk issued VDSL2 modem I'm aware of that has access to the Broadcom CLI via telnet and works with DslStats. It should in theory allow setting a maxdatarate and then allowing you to monitor the ES numbers to remove interleaving.
Personally I think the HG635 is a much better piece of kit than the HG633. The HG635 has 4 gigabit LAN ports, and a fully accessible telnet interface. The HG633 only has 100mb LAN ports, none are gigabit. It appears to have a Triductor modem, which to be honest I've never even heard of.
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There's no such thing as a line retrain on FTTC DLM. It's a 100% hands off system. There's absolutely nothing any ISP can do to "tweak" anything on the line.
The only way I know of to help remove interleaving would be using a Broadcom based modem and setting maxdatarate via the telnet interface. Limiting the sync speed to a figure considerably lower than the attainable for around 10 days can push the all important Error Seconds (ES) down low enough for DLM to remove interleaving.
The Huawei HG633 doesn't have this ability, but the Huawei HG635 may. It's the only Talktalk issued VDSL2 modem I'm aware of that has access to the Broadcom CLI via telnet and works with DslStats. It should in theory allow setting a maxdatarate and then allowing you to monitor the ES numbers to remove interleaving.
Personally I think the HG635 is a much better piece of kit than the HG633. The HG635 has 4 gigabit LAN ports, and a fully accessible telnet interface. The HG633 only has 100mb LAN ports, none are gigabit. It appears to have a Triductor modem, which to be honest I've never even heard of.
appreciate the response, unfortunately 1. time is a big limiting factor and 2. looks like I have to send the 635 back to TT to avoid being billed for the 633 :( I wasn't on about a tweak from ISP, just a reset of connection to see if DLM then settled it any better...
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Openreach won't (officially) reset the connection unless a line fault has been diagnosed and repaired. TT can't do it directly themselves.
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They want the older HG635 back? Why? They no longer (and haven't for a long time) provided that model. Talktalk have never asked me to send an old router back. I have about 4 in the cupboard.
Which gives you the best sync? The HG635 is definitely the favoured model. If that syncs better I would suggest returning the newer HG633.
As Roseway detailed a little more than my previous comment, the ISP cannot reset the DLM on your line. They cannot even request OpenReach to do so. Only an on site OpenReach engineer can reset the DLM. They are instructed to only do this if a fault is found and repaired.