ADSL2+ Reliability Problems

JamesAllen · Nov 28, 2010, 12:00:54

Right an update. After 6 days of uptime my router lost routing last night again annoyingly. Same symptoms as always - router synced but no traffic can get to the default gateway.

Now what is weird is that I notice that my sync rate is suddenly the highest it's ever been. When I re-synced 6 days ago it was about 14200 or something like that. When I checked the router during the loss of routing yesterday it was synced at 16256. I thought once the router synced, the rate wouldn't change unless it re-negotiated the connection? The up stats showed the router had been up for 6 days but the sync rate has definitely changed.

I rebooted the router again and the high sync rate remained. I just did a speed test and I'm hitting the highest speeds I've ever had.

Still confused as to what could be causing this and it is quite concerning as my connection while perfect for the majority of time is unreliable every week or so.

Rik · Nov 28, 2010, 12:08:35

The only thing I can think of is trying a different router. Sorry, James.

JamesAllen · Nov 28, 2010, 12:12:33

I think that may have the to be the next test.

I'm hoping it's not a router fault as it was brand new although obviously it's possible. The only thing is, with the newest Netgear Firmware it would lose routing every 2 days or so. I then upgraded to the custom DGTeam FW and it now stays up for 5-6 days so something has changed. I suppose I'd expect if it was a hardware problem to still fail after 2 days but then nothing is obvious with this.

I may borrow the test router of the IDNet guys and see how that goes.

Rik · Nov 28, 2010, 12:16:03

It's got to be worth a try - eliminating the router is the next logical step.

Steve · Nov 28, 2010, 12:17:11

Have you tried static IP addresses or DHCP IP address reservation?

JamesAllen · Nov 28, 2010, 12:22:20

It's currently just using DHCP to obtain it's static IP. Could manually configuring the IP have an effect?

When I lose routing everything appears ok in terms of the router stats (sync, IP, gateway etc).

JamesAllen · Nov 28, 2010, 13:18:57

Just thinking about this some more. It may be coincidence but when I had a previous routing loss I also suddenly saw an increase in sync rate - higher than I'd ever had. Now with last nights problem again I see a sync rate higher than ever before. Ok, when it failed last week my sync dropped a little but still.. Wondering if it could be improvements at the exchange? It does appear that I keep getting improvements in sync as the weeks go by but also these loss of routing issues...

Food for thought.

Rik · Nov 28, 2010, 15:39:46

Definitely, James. If the loss of routing occurs between midnight and 7am, it could be BT's 21CN upgrade work.

JamesAllen · Nov 28, 2010, 15:41:59

It occurred before midnight yesterday and another time was during the afternoon so it seems to be quite random when it occurs. Though I did have a failure during the early hours a few weeks ago.

Still something to bear in mind though. The fact I am no synced at the highest I ever have could be some indication on changes to my line I would think.

Rik · Nov 28, 2010, 15:43:39

It could, it could just be less noisy times. I had a resync during the week around 2pm, and came back up at a slightly higher speed. Nothing to indicate what triggered the event though.

JamesAllen · Nov 28, 2010, 15:46:35

What is confusing me is that when I last rebooted - 6 days ago the sync rate was at 14200 and then last night it jumped to 16300 but the stats still said it had been connected for 6 days. Surely on a re-sync the connection stats should reset on the router? I.E. Sync rate can only change upon a new connection being established?

Rik · Nov 28, 2010, 16:00:25

They should reset, if you're looking at the WAN and not the LAN figure.

JamesAllen · Nov 28, 2010, 16:09:29

Yeah its the WAN connection stats. The sync rate had definitely changed but was still showing it had been connected for 6 days... Really weird.

Of course it may have re-synced not long after the last reboot and I just didn't notice ...

Rik · Nov 28, 2010, 16:11:32

Or the router is acting up.

JamesAllen · Nov 29, 2010, 21:14:50

Well after 44 hours it's just lost routing again.

Weird thing, once again is that I notice the sync rate is different BEFORE it has reconnected. It's at 14315 kbps. Now either the router lost sync shortly after the last problem and re-connected or something strange is going on here.
It's impossible for the sync rate to change while connected right?

I've just configured the router manually to use it's static IP, rather than using DHCP to obtain it. Will see if that helps.

Steve · Nov 29, 2010, 22:03:39

SRA or seamless rate adaption

http://forums.thinkbroadband.com/sky/2924249-sky-broadband-and-sra-seamless-rate-adaptation.html

Basically SRA (Seamless Rate Adaptation) is a feature of ADSL2+ which varies your line speed depending on the line quality or SNR (Signal to Noise Ratio) without actually having to re-sync, so basically you always have the fastest line speed for the current line conditions. This is different to ADSL1 which would re-sync to a slower speed, briefly loosing the connection, and will not sync back up if quality improves.

But as far as I am aware BT have not implemented this facility on their version of adsl2+

Good luck with the use of a static IP, it will take the DHCP server out as possible cause of loss of routing.

JamesAllen · Nov 29, 2010, 22:24:59

Thanks Steve - excellent information.

That does sound like what I'm seeing although it's hard to know if the router did re-sync not long after the last reboot. Looking at my logs now I see a message from 00:12 last night saying 'Router starting up' but the connection time when it failed a few hours ago was 44 hours. Weird.

It would be interesting to know for sure if SRA is not part of the current BT ADSL2+ implementation.

Will have to see if the manual IP configuration has an effect. If not the next step is trying a fix I saw related to the problems o2 customers were having with Netgear routers which matches what I'm seeing. Although I have already enabled a mode in the DGTeam firmware which was supposed to fix that anyway.

Time will tell.

JamesAllen · Nov 29, 2010, 22:44:39

Just to add to this, in the DGTeam firmware Seamless Rate Adaptation is set to on, so if it is supported by the exchange it would certainly be in effect.

Rik · Nov 30, 2010, 10:06:24

Afaik, BT haven't implemented it - the cheapskates.

JamesAllen · Dec 14, 2010, 12:24:13

Hi guys,

An update to my issue. I went away last week and once again the router failed - around 5-6 days since the last failure.

Now here's the weird part, I contacted IDNet support and they said the router had disconnected but it wasn't trying to re-connect. Now this fits with what I've seen before in that when it fails it remains synced and states 'Connected' in the status panel. It stayed down for over a day, but then suddenly decided to re-connect. I have no idea why it would suddenly do this.

Anyway, it just failed again last night. 5-6 days since the last re-connect. The duration seems to be fairly consistent between problems.

So IDNet support confirms that during these outages the router does disconnect but it appears that it still thinks it is fully connected and so doesn't bother trying to re-connect. Very weird and very annoying.

However it sounds like a router problem. Annoying as I bought it new off ebay but probably no way to get it sorted out..

Would just love to know why it seems to be fine for 5-6 days then loses connection but doesn't think it has..

Rik · Dec 14, 2010, 12:27:12

Over-heating?

JamesAllen · Dec 14, 2010, 12:29:43

Quote from: Rik on Dec 14, 2010, 12:27:12
Over-heating?

Good idea, although I don't think it's that as all I have to do is reapply the settings (without rebooting) and it re-connects then stays up for another 5-6 days or so. I'd think it would fail sooner if it was over heating perhaps. Hard one to diagnose. When it fails the internet light is active and flashing until I get it to re-connect.. That seems weird to me as well.

Rik · Dec 14, 2010, 12:31:11

I think you have to try a different router, James, to prove one way or another if that one is fritzed.

JamesAllen · Dec 14, 2010, 12:34:09

Quote from: Rik on Dec 14, 2010, 12:31:11
I think you have to try a different router, James, to prove one way or another if that one is fritzed.

Defo, I think you're right. Gone as far as I can with this testing now I think. Was good to have it fail while I was a way from home so support could check the line. Surprised me that it came back up after a day or so though.. Was like it finally realised it was disconnected.. lol.

JamesAllen · Dec 14, 2010, 12:35:13

My only problem now is the only router I have is a v2 DG834 router which I hear is that not great for ADSL2+. I have flashed it to the latest firmware but I wonder how good a test it'll be and what kind of performance hit I'll take.

It's a test though I suppose. IDNet have no test routers available for me to use unfortunately.