ADSL2 drop outs

Connection issues, drop outs or speed related faults for ADSL and ADSL2+ services
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-MadDog-
Posts: 19
Joined: Thu Jan 10, 2008 8:38 am
Location: Weipa

ADSL2 drop outs

Post by -MadDog- » Fri Sep 03, 2010 5:26 pm

Well we are currently having some drop outs with our connection.

We only just upgraded to ADSL2 last week, but when we were on our 8Mb connection we would get drop outs as well.

They are fairly random, as in no set times. It can be a couple of days between dropouts, and then you can get 5 in 5 min.

The router is a BiPAC 7404VNPX, and its the only thing connected to our lines. I have disconnect the phone from the voip router so there is only one cable going into the router from the wall with no filter.

This is the status when the connection has dropped out:
Image

Settings in the router:
Image

Image

And once the connection is back up I get this:

Image

Image

Image

And this is from the event log (sample):
Sep 03 17:02:10 home.gateway:turbo_extEvtHandlerProc:none: ADSL line is DOWN!
Sep 03 17:02:49 home.gateway:turbo_extEvtHandlerProc:none: ADSL line is UP!
Sep 03 17:02:56 home.gateway:sip_SipTransactionManager_?:none: SIP Registration successful for phone 09382795
Sep 03 17:03:04 home.gateway:turbo_extEvtHandlerProc:none: ADSL line is DOWN!
Sep 03 17:03:43 home.gateway:turbo_extEvtHandlerProc:none: ADSL line is UP!
Sep 03 17:03:46 home.gateway:sip_SipTransactionManager_?:none: SIP Registration successful for phone 09382795
Sep 03 17:03:59 home.gateway:turbo_extEvtHandlerProc:none: ADSL line is DOWN!
Sep 03 17:04:53 home.gateway:turbo_extEvtHandlerProc:none: ADSL line is UP!
Sep 03 17:04:55 home.gateway:sip_SipTransactionManager_?:none: SIP Registration successful for phone 09382795
Sep 03 17:05:08 home.gateway:turbo_extEvtHandlerProc:none: ADSL line is DOWN!
Sep 03 17:05:48 home.gateway:turbo_extEvtHandlerProc:none: ADSL line is UP!
Sep 03 17:05:51 home.gateway:sip_SipTransactionManager_?:none: SIP Registration successful for phone 09382795
Sep 03 17:06:22 home.gateway:turbo_extEvtHandlerProc:none: ADSL line is DOWN!
Sep 03 17:07:00 home.gateway:turbo_extEvtHandlerProc:none: ADSL line is UP!
Sep 03 17:07:03 home.gateway:sip_SipTransactionManager_?:none: SIP Registration successful for phone 09382795
Sep 03 17:07:22 home.gateway:turbo_extEvtHandlerProc:none: ADSL line is DOWN!
Sep 03 17:08:01 home.gateway:turbo_extEvtHandlerProc:none: ADSL line is UP!
Sep 03 17:08:08 home.gateway:sip_SipTransactionManager_?:none: SIP Registration successful for phone 09382795
Sep 03 17:08:23 home.gateway:turbo_extEvtHandlerProc:none: ADSL line is DOWN!
Sep 03 17:09:02 home.gateway:turbo_extEvtHandlerProc:none: ADSL line is UP!
Sep 03 17:09:18 home.gateway:turbo_extEvtHandlerProc:none: ADSL line is DOWN!
Sep 03 17:09:57 home.gateway:sip_SipTransactionManager_?:none: SIP Registration Error 1 for phone 09382795
Sep 03 17:10:25 home.gateway:turbo_extEvtHandlerProc:none: ADSL line is UP!
Sep 03 17:10:54 home.gateway:turbo_extEvtHandlerProc:none: ADSL line is DOWN!

----------- system log buffer tail --------------
So if anyone has any suggestions on what i can do it would be greatly appreciated :D

Cheers

Dazzled
Volunteer Site Admin
Posts: 6003
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Location: Sydney

Re: ADSL2 drop outs

Post by Dazzled » Fri Sep 03, 2010 6:30 pm

I don't know when each of the two status pages were done, but they tell a story:
1) Attenuation 47, SNR margin 6.85
2) Attenuation 47.5, SNR margin 27
with very different speeds.

That is a highly attenuated line, probably about 3.5 km long, and it doesn't take much added noise to make the high frequency ADSL2 analogue signal "inaudible". In case (1) the noise margin was tight, which also means the transmission rate may be too fast for all circumstances. Stability profiles, when applied, slow the rate to gain better noise handling. The intermittent nature of this doesn't seem consistent with permanently bad joints etc on the external phone line, and can make the cause hard to find. It might be an idea to watch for interference from your home, like an appliance, or television (this happened in the forum as recently as today). If you can arrange a modem swap it could be worthwhile, in case the Billion is flaky. Keep all phone line cables to the modem short - they can collect interference.

If you raise a support ticket the line can be tested, but the intermittent aspect may spoil that.

outbush
Posts: 327
Joined: Fri Jun 08, 2007 8:49 am

Re: ADSL2 drop outs

Post by outbush » Fri Sep 03, 2010 10:54 pm

-MadDog- wrote:Well we are currently having some drop outs with our connection.

We only just upgraded to ADSL2 last week, but when we were on our 8Mb connection we would get drop outs as well.

They are fairly random, as in no set times. It can be a couple of days between dropouts, and then you can get 5 in 5 min.

The router is a BiPAC 7404VNPX, and its the only thing connected to our lines. I have disconnect the phone from the voip router so there is only one cable going into the router from the wall with no filter.
......................

So if anyone has any suggestions on what i can do it would be greatly appreciated :D

Cheers
It seems that your modem is trying to sync to high (= more dropouts)for your line attenuation.
Try setting your"Connect Mode" to ADSL2+(auto fallback) if this is available
and set your "Coding Gain" to 5 (if your line is more stable, maybe 6)
apply settings and save config

Dazzled
Volunteer Site Admin
Posts: 6003
Joined: Mon Nov 13, 2006 1:16 pm
Location: Sydney

Re: ADSL2 drop outs

Post by Dazzled » Sat Sep 04, 2010 8:03 am

Thanks for the tip for increasing MadDog's noise margin Outbush. These Billions default to "auto" - is there a simple way for users to discover the actual gain (0 dB to 7 dB) which was automatically selected?

-MadDog-
Posts: 19
Joined: Thu Jan 10, 2008 8:38 am
Location: Weipa

Re: ADSL2 drop outs

Post by -MadDog- » Sat Sep 04, 2010 8:44 am

Hey guys, thank you very much for the replies.

Dazzled, the two status pages were taken about 5 min apart. One was when the modem first connected back up, and the other was about 5min after that, you can see it on the 'elapsed time'.

Here is that status from this morning:
Image

And here is the status after changing the connect mode and coding gain to what outbush said (ADSL2+(auto fallback), 5):
Image

Are these numbers any better? I will leave it on these settings and see if there is any dropouts anyway.

Cheers

outbush
Posts: 327
Joined: Fri Jun 08, 2007 8:49 am

Re: ADSL2 drop outs

Post by outbush » Sat Sep 04, 2010 12:29 pm

Dazzled wrote:Thanks for the tip for increasing MadDog's noise margin Outbush. These Billions default to "auto" - is there a simple way for users to discover the actual gain (0 dB to 7 dB) which was automatically selected?
Thats a question for the Billion Forums.

CoreyPlover
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Posts: 5922
Joined: Sat Nov 04, 2006 2:24 pm
Location: Melbourne, VIC

Re: ADSL2 drop outs

Post by CoreyPlover » Sun Sep 05, 2010 1:21 pm

outbush wrote:
Dazzled wrote:Thanks for the tip for increasing MadDog's noise margin Outbush. These Billions default to "auto" - is there a simple way for users to discover the actual gain (0 dB to 7 dB) which was automatically selected?
Thats a question for the Billion Forums.
This was asked in an old thread (http://au.billion.com/forums/index.php? ... &pid=45828) and it never got answered

In fact, even the meaning of "coding gain" wasn't fully determined: http://au.billion.com/forums/index.php? ... entry32977
I am a volunteer moderator and not an Exetel staff member. As with all forum posts, mine do not constitute any "official" Exetel position. Support tickets may be logged via https://helpdesk.exetel.com.au or residentialsupport@exetel.com.au

outbush
Posts: 327
Joined: Fri Jun 08, 2007 8:49 am

Re: ADSL2 drop outs

Post by outbush » Sun Sep 05, 2010 7:54 pm

CoreyPlover wrote:
outbush wrote:
Dazzled wrote:Thanks for the tip for increasing MadDog's noise margin Outbush. These Billions default to "auto" - is there a simple way for users to discover the actual gain (0 dB to 7 dB) which was automatically selected?
Thats a question for the Billion Forums.
This was asked in an old thread (http://au.billion.com/forums/index.php? ... &pid=45828) and it never got answered

In fact, even the meaning of "coding gain" wasn't fully determined: http://au.billion.com/forums/index.php? ... entry32977
Well I guess as it is a Billion secret, users should not be making adjustments to their settings to obtain better performance.

CoreyPlover
Volunteer Site Admin
Posts: 5922
Joined: Sat Nov 04, 2006 2:24 pm
Location: Melbourne, VIC

Re: ADSL2 drop outs

Post by CoreyPlover » Sun Sep 05, 2010 10:55 pm

I always thought that "coding gain" was synonymous with "Extra SNR Margin" but now I'm not sure because it sounds like it acts in the opposite direction (higher SNR margin usually means slower speeds, whereas here, the maximum coding gain of 7dB results in highest speeds) and it can't be synonymous with "how much lower would you like the SNR margin" because otherwise a 7dB coding gain would result in about 2-3db of SNR margin which is way too small for ADSL2+ to operate with stability.

Trying to reconcile "coding gain" to the Wikipedia article, it almost reads as though it is a variable error correcting code; one that allows you to tailor the threshold at which transmission errors are correctable or whether the packet is dropped and re-requested. By increasing this, even though the packets are larger in overhead, it may result in no (or few) re-requested packets, thus increasing the overall throughput.
I am a volunteer moderator and not an Exetel staff member. As with all forum posts, mine do not constitute any "official" Exetel position. Support tickets may be logged via https://helpdesk.exetel.com.au or residentialsupport@exetel.com.au

-MadDog-
Posts: 19
Joined: Thu Jan 10, 2008 8:38 am
Location: Weipa

Re: ADSL2 drop outs

Post by -MadDog- » Mon Sep 06, 2010 6:58 pm

So would anyone have any more suggestions because i am still getting drop outs? Just had a few in the last half an hour.

Should i change the coding gain to something else?

Cheers

CoreyPlover
Volunteer Site Admin
Posts: 5922
Joined: Sat Nov 04, 2006 2:24 pm
Location: Melbourne, VIC

Re: ADSL2 drop outs

Post by CoreyPlover » Tue Sep 07, 2010 1:36 pm

I don't think coding gain affects drop outs, mainly speeds, but I could well be wrong and it can't hurt trying 0dB instead of 7dB.

Otherwise, I would be logging a fault. The sudden spike in attenuation after the drop out in your sync stats suggests some sort of "burst" of interference, and if you've rule out local devices then the interference may be coming into your line from an external source. It is going to be very difficult to track it down however if it is so intermittent.
I am a volunteer moderator and not an Exetel staff member. As with all forum posts, mine do not constitute any "official" Exetel position. Support tickets may be logged via https://helpdesk.exetel.com.au or residentialsupport@exetel.com.au

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