In the absence of Adam Walker

[#1]

Hi Alex,
Thanks for your explanattion.  That makes some sense.
Regards,
Chandu.

[#2]

@Adam Walker or Alex Rolls,
I notice that since 09.05 on 22nd August my line has been very unstable and the frequency of line disconnect is gradually increasing.   The line stability since completion of work on 14th July did not last very long.  I fear that this may lead to going through long process of fault finding etc.
Do I now raise a ticket for fault or wait for a few days more?
Many regards,
Chandu.

[#3]

Hi chandu,
Your line is not dropping particularly heavily but is occasionally dropping out.

I have made some adjustments to your line configuration in an attempt to achieve a fully stable connection.  This involved raising the line SNR margin to 12dB (previously 6dB) and enabling interleaving.  If the line is fully stable we can lower your SNR margin to 9dB to see if we can improve the performance further.  The goal currently is to achieve stability.

[#4]

Thank you Alex.
I may be little thick here, for which please forgive me.  I notice from my router's statistics, which is copied below, that though the router has been on 24/7 since 14th July as the system up time suggests, but I keep losing WAN - PPPoA, which resets the timer.  WLAN, which I believe is to do with my wireless connection/s and it differs from the system up time because some 146 hours ago I had reset my SSID and the WPA/PSK encryption key.  The worrying part is the losss of PPPoA.  Is this something to do with Plusnet or is it to do with BT's state of the line?  Please explain the above to me in very simple terms, so that I can increase my knowledge base and enable me to understand things better!
My Router Statistics: at 15:10 today
System Up Time 406:38:16
Port Status TxPkts RxPkts Collisions Tx B/s Rx B/s Up Time
WAN PPPoA 3773 5150 0 19 157 09:20:42
LAN 10M/100M 41104 7904 0 8 0 406:38:11
WLAN 11M/54M 1028587 815289 0 2279 263 146:54:56
ADSL Link Downstream Upstream
Connection Speed 3071 kbps 448 kbps
Line Attenuation 61.5 db 34.1 db
Noise Margin 7.3 db 18.3 db
I will appreciate your feedback on this.  Thanks.
Regards,
Chandu.

[#5]

Fundamentally there are two stages to the connection process.
- Synchronisation
- Authentication (via PPPoA)
The PPPoA status relates to the authentication status of your modem.  Your router sends out your Plusnet username and password to our systems and establishes a PPP session with us.  If your PPP session is lost then this could be because:
- You have lost the link with our systems but not lost synchronisation
- You have lost the link with our systems because you have lost synchronisation
The router logs will contain information on whether just PPP was lost or both PPP and Sync.  The graphing we regularly post on threads and tickets like this one:

Are simply graphs of your PPP status.  Each vertical line is a loss of PPP session.  Hope that helps.

[#6]

Thank you Alex for the clarification.
I have been to Kitz forum and found the following comment/s with regard to loss of PPPoA session:

Quote

The dropping PPPoA session could possibly be the result caused by the ISP's equipment or the interface between the exchange and the ISP.

What are your thoughts on the above comment/s?

[#7]

Dropping PPPoA simply means the PPP session was lost between your router and our systems (RADIUS).  There are lots of points between your router and our RADIUS system that could cause this.  I have tested your line thoroughly including ensuring our configuration is correct and no fault was found.

[#8]

Quote from: Alex

I have tested your line thoroughly including ensuring our configuration is correct and no fault was found.

I just had another PPPoA session drop at 17:33.  The router stats are:
System Up Time 409:15:38
Port Status TxPkts RxPkts Collisions Tx B/s Rx B/s Up Time
WAN PPPoA 1197 1641 0 326 5701 00:06:01
LAN 10M/100M 41327 7904 0 8 0 409:15:33
WLAN 11M/54M 1065237 849304 0 2313 272 149:32:18
ADSL Link Downstream Upstream
Connection Speed 2639 kbps 444 kbps
Line Attenuation 61.5 db 34.1 db
Noise Margin 12.3 db 18.0 db
The SNRM Down is 12db and Up is 18db which has now resulted in Downstream speed of 2639 kbps and upstream speed of 444 kbps.
Would your configuring the SNRM from 6 to 12db cause the drop of PPPoA session?  And, are the upstream and Downstream speeds as they should be?
Regards,
Chandu.

[#9]

Quote

Would your configuring the SNRM from 6 to 12db cause the drop of PPPoA session?

Yes, it will cause a resync with the exchange at the new SRNM, which, in turn, will cause a drop of the PPPoA session.

[#10]

Quote from: MisterW

Yes, it will cause a resync with the exchange at the new SRNM, which, in turn, will cause a drop of the PPPoA session.

Thanks MisterW.  I wan't sure that's why I asked.  Much appreciated..
Regards,
Chandu.
jim:green quote fixed mod:end

[#11]

@Alex
I have just done BT Speed Test (at 19.10) after you have reset SNRM from 6 to 12db with interleaving on,  Though the IP profile has dropped from 2.5 to 2.0 Mbps, the downstream speed achieved was 1.9mbps and upstream speed is at 0.366Mbps.  So, I am quite happy with these speeds (considering my line length) as long as they stay that way and the PPPoA does not drop and stabilises.  Please leave things as they are and lets see how we fare.
Regards,
Chandu.

[#12]

Hi Chandu,
Glad to hear things have improved again. The current connection has been up for just over 16 hours so its just a game of wait-and-see at the moment....
Alex is away until next week so I'll keep an eye on things in the meantime.
Adam

[#13]

Hello Adam,
Welcome back.  I think Alex deserves a well earned rest and fun. 
Yes agreed.  The connection has been up for over 17 hours now.  But according to BT Speed Test this afternoon, my downstream speed has now dropped to 1.68Mbps and the upstream is at 0.338Mbps.
Certainly I will appreciate if you could please keep an eye on PPPoA drops. 
Thank you.
Chandu.

[#14]

Hello again, Adam,
It appears that my line has stabilised well, except for occassional drop.  Do you think it is time to drop the SNRM from 12 dB to 9dB, with interleaving still ON?
Incidentally, where is Alex?  Has he been assigned a new project?
Thank you in advance and I await your feedback.
Chandu.

[#15]

Hi Chandu,
Granted you are getting some longer connections but if the line is dropping it's probably better to leave things as they are - with a lower SNR you'll certainly see more connection drops than you are doing currently.
If you did want to change the SNR settings to see what happened to the line the best bet would be to get a router that's compatible with Routerstats, which will allow you to specify the SNR you'd like from your own router - there's several users on here that know all about that, a search through or post in the hardware board would certainly get you the information you need to go ahead with that. That way you can try the 9dB SNR and keep it if you wish, or set it back to 12 if you find it's more unstable than you'd like.
Hope that helps,