cancel
Showing results for 
Search instead for 
Did you mean: 

Connection Drops

buylow
Dabbler
Posts: 17
Registered: ‎26-11-2008

Connection Drops

Hi,
My parents are having some problems with connection drops. Their exchange has been upgraded to ADSL2+ and
their line appears to have been upgraded. This would be fine if it worked (more speed!) but their connection keeps dropping, usually after about 13 minutes, and they have to reboot the modem to continue. By logging in to the modem I can do a soft reboot every time the connection fails, but they have to power it off/on.
I have raised a ticket, and plusnet got interleaving turned on. I have also tidied up some wiring which may have helped. One or other of these changes seems to have moved the SNR from about 11 to about 18.
They have a Tenda WBR-T2 modem which is on the list at http://community.plus.net/library/hardware/adsl2-hardware/ as being ok for adsl2+
Using telnet to get the stats gives:

        ADSL Link Info
adsl: ADSL driver and PHY status
Status: Showtime  Channel: FAST, Upstream rate = 440 Kbps, Downstream rate = 9727 Kbps
Link Power State: L0
Mode:                  ADSL2+
Channel:                Fast
Trellis:                U:ON /D:ON
Line Status:            No Defect
Training Status:        Showtime
                Down            Up
SNR (dB):      17.8            31.6
Attn(dB):      35.5            13.7
Pwr(dBm):      0.0            12.3
Max(Kbps):      19432          888
Rate (Kbps):    9727            440
                        G.dmt framing
K:              127(0)          56
R:              16              8
S:              1              1
D:              96              8
                        ADSL2 framing
MSGc:          71              12
B:              126            55
M:              1              1
T:              2              1
R:              16              8
S:              0.4161          4.0000
L:              2749            128
D:              96              8
                        Counters
SF:            2190            2188
SFErr:          0              32
RS:            337322          148784
RSCorr:        0              0
RSUnCorr:      0              0
HEC:            0              7
OCD:            0              0
LCD:            0              0
Total Cells:    810849          317136
Data Cells:    60              1018
Drop Cells:    0
Bit Errors:    0              186
ES:            0              0
SES:            0              0
UAS:            33              61

Any thoughts on what to try now? (and anyone know what Pwr is?)
plusnet's latest reply said "the router you are using is an ADSL and not ADSL2 router" which seems plain wrong, the stats say "Mode:                  ADSL2+".
If buying a new router is the thing to try, any suggestions on make/model? (I meant to bring mine with me to try when I came to visit but I forgot - my bad.)
Thanks for any suggestions
15 REPLIES
sjrinfroyle
Grafter
Posts: 895
Registered: ‎08-05-2011

Re: Connection Drops

One thing that I can point out. Interleaving is not turned on. It it showing "fast" in your connection logs. If the fault it still open, say that interleaving is not on or if not open a new one and say the interleaving order has failed.
buylow
Dabbler
Posts: 17
Registered: ‎26-11-2008

Re: Connection Drops

I wondered about that. I've turned logging on and when starting up the logs say things like:

Jan 1 00:00:30 user crit kernel: ADSL G.992 message exchange 
Jan 1 00:00:31 user crit kernel: ADSL link down 
Jan 1 00:00:36 user crit kernel: ADSL G.994 training 
Jan 1 00:00:43 user crit kernel: ADSL G.992 started 
Jan 1 00:00:47 user crit kernel: ADSL G.992 channel analysis 
Jan 1 00:00:54 user crit kernel: ADSL G.992 message exchange 
Jan 1 00:00:54 user crit kernel: ADSL link up, interleaved, us=440, ds=9727 
Jan 1 00:00:55 user debug syslog: iptables -t nat -A PREROUTING -i br0 -d 192.168.0.1 -p udp --dport 53 -j DNAT --to 128.9.0.107 
Jan 1 00:00:55 daemon notice pppd[667]: PPP: Start to connect ... 
Jan 1 00:00:55 daemon crit pppd[667]: PPP server detected. 
Jan 1 00:00:56 daemon crit pppd[667]: PPP session established. 
Jan 1 00:00:56 daemon crit pppd[667]: PPP LCP UP. 
Jan 1 00:00:57 daemon crit pppd[667]: PPP LCP UP. 
Jan 1 00:00:57 daemon crit pppd[667]: Received valid IP address from server. Connection UP. 

So I'm not sure if interleaving is on or off. I'll try and be patient and see if anything else changes in the next day or so ...
Community Gaffer
Community Gaffer
Posts: 17,667
Thanks: 659
Fixes: 163
Registered: ‎05-04-2007

Re: Connection Drops

I *think* I've found the right account, and just performed a quick check on the line and it's confused me too.
Interleaving is showing as 'opt-in', which should mean it's turned on. However run mode is showing as fastpath not interleaved.
I'll ask one of our faults guys to take a look.
If this post resolved your issue please click the 'This fixed my problem' button
 Chris Parr
 Plusnet Staff
Community Veteran
Posts: 4,890
Thanks: 129
Fixes: 24
Registered: ‎14-07-2009

Re: Connection Drops

Quote from: buylow
... I've turned logging on ...

It might be a good idea to set the correct time on the router, then you'll know when the logged events really happened.
buylow
Dabbler
Posts: 17
Registered: ‎26-11-2008

Re: Connection Drops

Quote from: Chris
I *think* I've found the right account, and just performed a quick check on the line and it's confused me too.
Interleaving is showing as 'opt-in', which should mean it's turned on. However run mode is showing as fastpath not interleaved.
I'll ask one of our faults guys to take a look.

Thanks Chris, see ticket 44701111
We bought another modem (Linksys WAG160N) today to see how that handled the line and it seems slightly better. I noticed the connection was down earlier but it came back up by itself with this modem. If the line is glitchy for some reason clearly it's better if the modem recovers by itself instead of us having to reboot it. I'm only here for a couple more days so I'd like to get it fixed by then if possible. Also if I get called to do remote support I need this line for VPN access to work so I've been trying to fix it asap.
buylow
Dabbler
Posts: 17
Registered: ‎26-11-2008

Re: Connection Drops

Quote from: ReedRichards
It might be a good idea to set the correct time on the router, then you'll know when the logged events really happened.

I don't know if it's possible to set the time on that router, the logs show that it gets the time from the internet fairly quickly when it is starting up. The messages I quoted were from before it had found the time, so it still showed Jan 1. Got a different modem now, so won't worry about this.
buylow
Dabbler
Posts: 17
Registered: ‎26-11-2008

Re: Connection Drops

Quote from: Chris
I'll ask one of our faults guys to take a look.

<bump>
Be interested to know what they found ...
(New modem doesn't seem to show any interleaving status, so I can't see anything from here)
Community Veteran
Posts: 4,890
Thanks: 129
Fixes: 24
Registered: ‎14-07-2009

Re: Connection Drops

Quote from: buylow
We bought another modem (Linksys WAG160N)

I hope it lasts.  I find Linksys routers can be short-lived.
Quote from: buylow
If the line is glitchy for some reason clearly it's better if the modem recovers by itself instead of us having to reboot it.

All routers that are working properly should re-establish a dropped connection.  Your old one was faulty.
jojopillo
Grafter
Posts: 9,786
Registered: ‎16-06-2010

Re: Connection Drops

Hi buylow,
I can see from the connection logs that the line is a lot more stable now. Either the old router was faulty or there was an idle timeout set on the other one (which I would have suspected, seeing that a lot of the disconnections were exactly 14 minutes)
Are things better now then?
Jojo Smiley
buylow
Dabbler
Posts: 17
Registered: ‎26-11-2008

Re: Connection Drops

Yes, it seemed fine over the weekend apart from when I was messing with the phone connection. (hadn't put a filter on it at first - understandable that might cause an issue!) The disconnections were very regular, but the problem was they happened even if I was using it, so the line was definitely not idle :-(
Seems good now anyway, thanks for asking. As you say, I guess the old modem was faulty.
So is interleaving on or off now from what you can see?
And what is the situation regarding line speed? From my (limited) understanding of the numbers, they could perhaps get a fair increase in speed although they don't have any large need for it. Will the line adapt by itself, or will it stay at the current speed unless something is changed at the bt/plusnet end?
Reliability is the main priority, so leaving it at the current speed is ok ...
dick:quote
Highlighted
jojopillo
Grafter
Posts: 9,786
Registered: ‎16-06-2010

Re: Connection Drops

Hi buylow,
The downstream is on fast path, so interleaving is off at the moment. As for the speed. The line is currently banded at 4M-9M so the maximum sync rate will be 9728Kbps. Currently the line is syncing at 9726Kbps, so it is performing at its optimum now. Before I suggest turning off the banding to get a better speed can I confirm that they are plugged into the master/test socket with no extensions between the socket and the router.
Jojo Smiley
buylow
Dabbler
Posts: 17
Registered: ‎26-11-2008

Re: Connection Drops

Quote from: Joanne
The downstream is on fast path, so interleaving is off at the moment. As for the speed. The line is currently banded at 4M-9M so the maximum sync rate will be 9728Kbps. Currently the line is syncing at 9726Kbps, so it is performing at its optimum now. Before I suggest turning off the banding to get a better speed can I confirm that they are plugged into the master/test socket with no extensions between the socket and the router.

Ok, I thought interleaving was turned on earlier, but then there was some confusion over whether it was on or off.
No, they're back to their "normal" setup with the modem in their usual socket. I think the stats are broadly similar anyway (e.g. SNR about 17 from memory).
Should they do this before you turn banding off? It seems like this would give a false impression of the line conditions? So it might change to some high sync rate, and then when they change back to the normal socket maybe it can't handle that high rate?? (probably trying to understand too much instead of just doing what you say, sorry.) Is there a downside to just turning the banding off with the current connection setup?
Thanks for the help, btw.  Smiley  I went and read some FAQs after my last post and learnt about DLM and banding, should have done that first.  Embarrassed
Do you have any thoughts on whether they're likely to see improved speeds? If they're only likely to see a smallish improvement and the line ends up banded again at a similar rate then maybe it's not worth the effort. On the other hand, if they're likely to get a good increase, maybe a 50% or 100% better rate, then maybe that's worth going for ...
jojopillo
Grafter
Posts: 9,786
Registered: ‎16-06-2010

Re: Connection Drops

HI buylow,
it's a fair point you have about the set up that they have. The thing is, do they need more speed? If not, then I would say leave it as it is. I'd say the line, in perfect condition, would be capable of 12-13000Kbps
About the test socket; it's a catch 22. In most cases (not all the time, of course) it will be internal wiring that will cause banding like this. I could remove the banding as it is, but I'd much rather remove it while it's in the test socket, as this will indicate a problem outside the property if it were to be banded again.
Jojo Smiley
buylow
Dabbler
Posts: 17
Registered: ‎26-11-2008

Re: Connection Drops

Hi Jo,
Ok, thanks for the comments. We'll leave it as it is, it ain't broke now so why fix it!
Thanks again for your help.  Smiley