Openreach VDSL modem throughput (was: Profile nudge please)

[#1]

Openreach just connected the FTTC. Currently synced at 79/19 but Plusnet profile still at 1.9Mbps.  
Edit: BT speedtester is working now. IP profile is 77.43Mbps down, 20Mbps up. (disregard the upstream - I forgot to set the new QoS speeds in the router)

[#2]

Hi there,
That should now be sorted for you. Let us know if there's still an issue.

[#3]

That's much better, thanks.
Still seems low though, compared to the BT profile, but regardless it's plenty fast enough. 

[#4]

Ugh, the Plusnet Profile has gone to 1.7Mbps. This appears to be a delayed update from the final ADSL connection I had (1946kbps). Presumably this won't happen again now that delta report is out of the way?
Can you please set my Plusnet profile again. BT IP profile is currently 77.43Mbps.

[#5]

Hi there,
I've just nudged the profile again but these dips in the profile speed will be happening for a reason that needs to be addressed.
Looking at your connection logs I can see a few drops which are likely to be what's caused/causing this so I'd keep an eye on that for now and consider raising a fault if that causes more problems:
<img src="http://ccgi.psmith12.plus.com/visradius/generated/image13582431319477.png"/>>

[#6]

Thanks, I'll keep an eye on it.
Having had a quick look, I think those were all user-initiated PPP drops to try and trigger a new delta report, router reboots due to settings changes, or things being unplugged whilst tidying up cables.

[#7]

I've found the source of the "low" download speed (yes, it feels wrong to call it low) and the good news is it isn't a line/cabinet/Plusnet issue.
I have a Draytek Vigor 2850Vn, but using the Openreach VDSL2 modem connected to the 4th ethernet port as WAN2, rather than its internal modem (WAN1).
The LAN4/WAN2 port on the Draytek appears to be auto-negotiating a 100Mbps half-duplex link, which is giving 55-60Mbps throughput. If I force 100Mbps Full Duplex, throughput drops to 4Mbps. If I force 100Mbps Half Duplex, I get the same 55-60Mbps as auto-negotiating.
I've swapped the Ethernet cable, so it looks like either a faulty Openreach modem, faulty router, or weird network interface compatibility. Bummer.
PS: Whilst I'm trying different router hardware - PPP drops won't upset the DLM right? I'm not touching the Openreach VDSL modem - I think it's been connected non stop since Monday.

[#8]

Quote

PPP drops won't upset the DLM right?

They shouldn't, only drops in synch should

[#9]

I've tried three routers with the following settings:

• Draytek Vigor 2850Vn 100Mb Full Duplex: 3-5 / 17 Mbps


• Draytek Vigor 2850Vn 100Mb Half Duplex: 50-55 / 17 Mbps


• Draytek Vigor 2850Vn Auto-negotiation: 50-55 / 17 Mbps


• Apple Airport Extreme 4th Gen 100Mb Full Duplex: 3-5 / 17 Mbps


• Apple Airport Extreme 4th Gen 100Mb Half Duplex: 50-55 / 17 Mbps


• Plusnet/Technicolor TG582n Auto-negotiation: No connection - "Concentrator not reachable"

I'm assuming it should work at 100Mb Full Duplex?

[#10]

It's showing that your line is currently syncing at over 70Mb/s, can you try a <a href="http://community.plus.net/library/broadband/fibre-help-how-to-set-up-a-pppoe-dialler-in-vistawindows-7/">PPPoE</a> connection direct to the modem bypassing the router and give the results from there? Full duplex is fine too.

[#11]

Interestingly, PPPoE direct from the laptop worked in both Half Duplex and Full Duplex modes (yet Full Duplex on both routers caused throughput to plummet).
There is something weird going on, excluding the issue with the modem's LAN port. I tried the VDSL modem integrated into the Draytek 2850 and it synced at 80/20 with plenty of noise margin. Yet throughput wouldn't go any higher than about 50-51Mbps, in spite of an IP profile of 77.43Mbps. I checked the modem stats and all of the errored second, CRC and FEC counters were zero, so it wasn't that. QoS enabled/disabled makes no difference. No other limits are set on the router itself. The whole LAN-side network is gigabit.
My estimate was 49.9Mbps - is there something set somewhere which is artificially limiting speed to that value?
I'm more than happy with the 50Mbps I'm getting, and don't need more than that, but I'm just curious whether something is "wrong" somewhere.

[#12]

Quote

is there something set somewhere which is artificially limiting speed to that value?

Nothing we're aware of, anything like a line profile on ours or BT's systems wouldn't actually reflect on a line estimate.