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Event Logging Query

shalom2010
Grafter
Posts: 972
Registered: 28-12-2012

Event Logging Query

Can someone confirm what "xDSL linestate down" in the event logging of the router actually means?
Does it mean a disconnection to Plusnet (like a PPP session) or does it mean the modem has re synched?
(NB: Although I have had three of the above within a five minute period a few days ago my BT IP Profile remains the same)
Thanks
4 REPLIES
Plusnet Alumni (retired) chrispurvey
Plusnet Alumni (retired)
Posts: 5,369
Fixes: 1
Registered: 13-07-2012

Re: Event Logging Query

Hi there,
The xDSL linestate down is a PPP drop and no sync is lost.
This can also relate to a drop in sync, however that does not appear to be the case here.
shalom2010
Grafter
Posts: 972
Registered: 28-12-2012

Re: Event Logging Query

Many thanks Chris, I thought maybe the case.
Community Veteran
Posts: 26,548
Thanks: 791
Fixes: 9
Registered: 10-04-2007

Re: Event Logging Query

I see xDSL down events which are loss of sync with the exchange where the PPP session does not drop. It depends upon how quickly the sync is re-established. Here's an extract from my router log:
<102> Feb 24 06:10:18 SNTP Synchronised to server: 212.159.13.50 
<102> Feb 24 07:10:18 SNTP Synchronised to server: 212.159.13.49
<102> Feb 24 08:10:18 SNTP Synchronised to server: 212.159.13.50
<102> Feb 24 09:10:18 SNTP Synchronised to server: 212.159.6.9
<37> Feb 24 09:12:47 LOGIN User admin logged in on TELNET (192.168.1.6)
<102> Feb 24 10:10:18 SNTP Synchronised to server: 212.159.6.10
<173> Feb 24 10:43:29 xDSL linestate down
<173> Feb 24 10:43:42 xDSL linestate up (ITU-T G.992.1; downstream: 7520 kbit/s, upstream: 832 kbit/s; output Power Down: 19.9 dBm, Up: 12.7 dBm; line Attenuation Down: 22.5 dB, Up: 14.5 dB; snr Margin Down: 6.1 dB, Up: 12.0 dB)
<102> Feb 24 11:10:18 SNTP Synchronised to server: 212.159.13.49
<102> Feb 24 12:10:18 SNTP Synchronised to server: 212.159.6.10
<102> Feb 24 13:10:18 SNTP Synchronised to server: 212.159.13.49
<102> Feb 24 14:10:18 SNTP Synchronised to server: 212.159.6.10
<102> Feb 24 15:10:18 SNTP Synchronised to server: 212.159.13.49
<84> Feb 24 15:16:47 IDS scan parser : tcp port scan: 173.194.41.137 scanned at least 10 ports at 80.229.*.*. (1 of 1) : 173.194.41.137  80.229.*.*    40    57  TCP 443->65162 [...R..] seq 618647986 ack 0 win 0
<102> Feb 24 16:10:19 SNTP Synchronised to server: 212.159.13.50
<102> Feb 24 17:09:57 SNTP Synchronised to server: 212.159.6.10
<102> Feb 24 18:09:57 SNTP Synchronised to server: 212.159.13.49
<132> Feb 24 19:00:14 PPP link down (Internet) [80.229.7.240]

<38> Feb 24 19:00:30 PPP CHAP Receive challenge from rhost ERX2.Reading2 (Internet)
<38> Feb 24 19:00:30 PPP CHAP Receive challenge from rhost pcl-ag05 (Internet)
<38> Feb 24 19:00:31 PPP CHAP Receive success (Internet)
<132> Feb 24 19:00:31 PPP link up (Internet) [80.229.7.240]

<84> Feb 24 19:00:45 IDS scan parser : tcp port scan: 173.194.35.133 scanned at least 10 ports at 80.229.*.*. (1 of 2) : 173.194.35.133  80.229.*.*    40    52  TCP 443->50833 [...R..] seq 3547599127 ack 0 win 0
<102> Feb 24 19:09:57 SNTP Synchronised to server: 212.159.13.50
<102> Feb 24 20:09:57 SNTP Synchronised again to server: 212.159.13.50

The loss of sync is at 10:43:29.
Further down you can see a loss of the PPP session. That is followed by the CHAP challenge messages as it re-authenticates before it comes up again.
If you have a total loss of the connection you will see
xDSL linestate down
PPP link down (Internet)
Chap challenge messages (the first is from BT as it interprets the @plusdsl.net and then tries to connect you to Plusnet, the second is from the Plusnet gateway, then the success message
PPP link up (Internet)
Incidently, on a 20CN exchange I saw a lot of xDSL (loss of sync events) on the TG582 on the standard firmware. Upgrading to the latest router firmware practically stopped them.
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)
Bright
Grafter
Posts: 363
Registered: 02-02-2013

Re: Event Logging Query

@jelv
It looks like you're on ADSL whereas the OP is on FTTC, presumably with the TG582n and its modified firmware. Which makes messages about xDSL linestate a bit anomolous (since the router doesn't, as far as I know, know anything about the VDSL line state!).