Fttc "Stuck" session.

Fttc went down at about 13:45 this afternoon, got back to find that sync was fine but no PPP.

Spoke to P/N support who claims they see me online and it's a stuck session, said it needs to be left out of Sync for an hour for the DLSAM/MSAN to notice and clear it.

Is this likely to be the case, whilst I'm sure a session can get stuck it strikes me as odd that they can't simply kill it from their end and that it would take the DSLAM/MSAN 1hr of being out of sync for it to notice.

Thankfully I have a backup ADSL2+ line with Pulse8 so i'm still online.

Recall this from the early days of the ADSL roll-outs but don't recall this happening on FTTC ever

If you have open reach modem plus a router, have you tried turning both off for a few seconds and back on.

Yes...

Even tried a different HG612 incase it was something to do with my unlocked one.

Tried rebooting the router (Even though pretty sure it didn't need it, Its quite happily authing to pulse8/TT on the other port/PPPoE1)

Router is an ER-X

/var/log/messages was showing Timeouts waiting for pad0 packets

Sounds like garbage. PPPoE sessions are surely under the ISP control, as you think.

Maybe whoever you spoke to isn't high enough to be able to kill it.

In reply to a post by RobertoS:

Sounds like garbage. PPPoE sessions are surely under the ISP control, as you think.

Maybe whoever you spoke to isn't high enough to be able to kill it.

I'm not totally unconvinced that something isn't up with the FTTC MSAN as i tried changing the username to bt_test@startup_domain and couldn't get a PPP session up to that either.

Edit:

Called them back they killed the stuck session from their end and it came up straight away.
Edit2:

Looking into this further it looks like it's an option available to the ISP in the BTwholesale self service toolset.

https://www.btwholesale.com/assets/documents/knowled...

Edited by dragon2611 (Tue 25-Aug-15 21:40:36)

In reply to a post by dragon2611:

I'm not totally unconvinced that something isn't up with the FTTC MSAN as i tried changing the username to bt_test@startup_domain and couldn't get a PPP session up to that either.

Because the PPPoE session with Plusnet was active.

Edit:

Called them back they killed the stuck session from their end and it came up straight away.
Edit2:

Looking into this further it looks like it's an option available to the ISP in the BTwholesale self service toolset.

https://www.btwholesale.com/assets/documents/knowled...

Quite.

Edited by RobertoS (Tue 25-Aug-15 22:07:29)

In reply to a post by MrSaffron:

Recall this from the early days of the ADSL roll-outs but don't recall this happening on FTTC ever

If you have open reach modem plus a router, have you tried turning both off for a few seconds and back on.

Sorry, it's a bit unclear what you meant here, and I'm sorry but that is poor advice as well.
Stuck sessions have not been uncommon on Plusnet including FTTC especially when the was a lot of network issues last Summer/Autumn, and they still do happen if the PPP is lost due to some ungraceful event anywhere between the user and Plusnet.

In some cases on FTTC, logging into the Router and clicking Disconnect for the PPP Internet session and then switching it off for a minimum of 10 minutes will sometimes clear the stale session.

Clicking Disconnect and powering off the Router should be done before even contemplating turning off the Modem - a reboot will do nothing to help clear any stale/stuck sessions.
If anyone is going to turn off their Modem, it should be turned off for at the very least 30 minutes and preferably a hour to ensure the sync loss doesn't get counted as a drop in connection and it resets some of the DLM counters. But it any event I'm not certain that turning off the modem will help resolve a stuck stale session.
Certainly on 20CN, turning off the Modem/Router for an hour always cleared stale sessions, and Plusnet gave similar advice for 21CN when they had quite a few stale session problems with those Network issues.

Unfortunately, in a lot of cases, it's still necessary to get Plusnet to kill the stale session.

If you can find the paperwork that says the DLM interprets an 30 minute or hour outage differently to a few seconds of no signal (not even the sync pre-amble) then happy to mode advice.

Have been doing the occasional full kit power cycle for a year now, and nothing untoward has resulted.

Also not I say 'I don't recall this happening' so now as you say it seems to be a PlusNet thing will add that to the memory core. Maybe other providers have it but just clear it and users are none the wiser.

I too have often done a few short (less than a minute) disconnections within quarter of an hour when swapping kit around and suffered no ill effects.

This 30 minute thing seems to be a recent "internet myth" to add to the many others . IIRC it first came along as an exaggerated way of waiting for a PPP session to drop normally at the ISP, for those with no (or no obvious) PPP session close facility in their router.

If I just want a re-sync until recently I just pulled the HG612 power cable out of the HG612 socket, not touching the router at all. Waited say 20 seconds and plugged it back in.

Edited by RobertoS (Wed 26-Aug-15 11:54:46)

In reply to a post by MrSaffron:

If you can find the paperwork that says the DLM interprets an 30 minute or hour outage differently to a few seconds of no signal (not even the sync pre-amble) then happy to mode advice.

Have been doing the occasional full kit power cycle for a year now, and nothing untoward has resulted.

Also not I say 'I don't recall this happening' so now as you say it seems to be a PlusNet thing will add that to the memory core. Maybe other providers have it but just clear it and users are none the wiser.

The details about some of the DLM counters are all over on kitz, especially the forum. Yes you can often get away with a quick resync now and again if you've had no other issues with your connection. DLM counts the disconnects in 15 minute intervals.

Plusnet forums were littered with threads last summer/autumn with the consequences of stale sessions as a result of some network outages (3 IIRC). I have no idea if the "problem" is just a Plusnet thing, I have not researched how other ISPs systems handle a stuck stale session should one arise, they may well clear it and users are none the wiser.

However, as I have already said rebooting/turning of the modem as opposed to clicking Disconnect and turning off the Router, will do nothing for a stale session. You must remember that if a users SNRM is below 6 at the time they will end up with a lower sync speed. Turning off/rebooting a modem should generally be an absolute last resort with connection problems.

In reply to a post by RobertoS:

I too have often done a few short (less than a minute) disconnections within quarter of an hour when swapping kit around and suffered no ill effects.

This 30 minute thing seems to be a recent "internet myth" to add to the many others . IIRC it first came along as an exaggerated way of waiting for a PPP session to drop normally at the ISP, for those with no (or no obvious) PPP session close facility in their router.

It is NOT an "internet myth" as far as FTTC - see my response to Mr.Saffron above. It may well have been distorted over the years as a consequence of Routers not having a Disconnect button for the PPP, but that is more likely to be in cases of combined modem/routers especially on ADSL/2+. If you do not have a Disconnect button, then you should "Pull the power plug" not just unplug it from the line.

In reply to a post by RobertoS:

If I just want a re-sync until recently I just pulled the HG612 power cable out of the HG612 socket, not touching the router at all. Waited say 20 seconds and plugged it back in.

IF you choose to do that, as mentioned above, if you have no other connection issues, fine, BUT it should be at least 30 seconds, there is specific Openreach guidance on that.

I didn't mention disconnecting the OR modem from the line.

The Openreach guidance refers to CPs needing to have their PPP session drop shorter than the re-sync time of the modem from whatever cause, so as to receive an update on the new sync speed which is triggered at PPP connection time.

Your post about 30 minutes or so, and your rigmarole about the procedure to follow, are most certainly the stuff of myth I'm afraid. Have you any official sources for your ideas?

DLM counters have nothing to do with this.

The 'pay' site makes a lot of misinterpretations about how DLM works based on the ASSIA v BT court case ruling, particularly about how the data from the 15 min bins is analysed.

The fact is though that this 30 min thing is a complete myth and irrelevant to how RAMBo analyses the 24hr data.

Edited by deleted (Wed 26-Aug-15 14:27:58)

I can't see anyone having mentioned unplugging from the BT socket only. Rebooting requires a power off and on.

In reply to a post by RobertoS:

I didn't mention disconnecting the OR modem from the line.

Excuse me You talked about pulling the power plug on your HG612. So now you are going to try and convince me it doesn't contain a modem

People are getting confused between two issues here, PPP sessions and Sync - which started because unfortunately Andrew's post mentioned resyncing the modem which I've already said will have no beneficial effect on a stuck stale session. Go read all the posts on Plusnet's forum last year where users did this to no avail.
I've tried to split out the two aspects here - resyncing and PPP sessions.
The Openreach guidance to which I made mention of the 30 seconds is specifically about a simple straightforward resync - nothing else, you have confused it by mentioning PPP again and that is a different bit of Openreach documentation.
Even AndyCHZ has quoted the Openreach guidance to which I was referring.

In reply to a post by RobertoS:

Your post about 30 minutes or so, and your rigmarole about the procedure to follow, are most certainly the stuff of myth I'm afraid. Have you any official sources for your ideas?

In reply to a post by AndyHCZ:

The fact is though that this 30 min thing is a complete myth and irrelevant to how RAMBo analyses the 24hr data.

Complete garbage. Go and read ALL the stuff on kitz where not only do Openreach documents and data get quoted, but I also prefer to believe the experts that work for Openreach and especially those at the coal-face that know about these issues rather than someone who just reads and quotes from Openreach documents and doesn't always get the technical interpretation correct.

In reply to a post by AndyHCZ:

The 'pay' site makes a lot of misinterpretations about how DLM works based on the ASSIA v BT court case ruling, particularly about how the data from the 15 min bins is analysed.

Another red herring, this is totally irrelevant to any of this.

In reply to a post by AndyHCZ:

DLM counters have nothing to do with this.

Correct, DLM counters have absolutely nothing to do with Stale sessions.

In reply to a post by broadband66:

I can't see anyone having mentioned unplugging from the BT socket only. Rebooting requires a power off and on.

It wasn't, it was just supposed to be a bit of clarification on how you should best resync the modem, and the issue has been confused again.

Mildly embarrassing.

I guess people from the 'pay' site also attend the monthly product group meetings with OR...

Disconnecting a modem from a line to most people means disconnecting the DSL cable at one end or the other. It doesn't mean causing a loss of sync by powering it down.

You seem to completely misunderstand everything about the subject, and not realise that everyone you are disputing the issue with here knows an awful lot more than you. Considering your odd interpretation of the language in several places perhaps your misconceptions are to be expected.

Gabbling on about problems people have had in the past on Plusnet and Kitz forums is pointless, particularly if you were involved in giving incorrect advice.

Equally pointless seems to be trying to educate you, so I for one will give up. I shall merely try to help people I find you misinforming.

However, before I go:-

Clicking Disconnect and powering off the Router should be done before even contemplating turning off the Modem

If you mean closing the PPP session, say so. Disconnecting means removing physical connections. It is possibly "best practice", but is rarely a necessity.

If anyone is going to turn off their Modem, it should be turned off for at the very least 30 minutes and preferably a hour to ensure the sync loss doesn't get counted as a drop in connection and it resets some of the DLM counters.

Utter drivel.

But it any event I'm not certain that turning off the modem will help resolve a stuck stale session.
Certainly on 20CN, turning off the Modem/Router for an hour always cleared stale sessions, and Plusnet gave similar advice for 21CN when they had quite a few stale session problems with those Network issues.

Everything you say after the first sentence of it contradicts that first sentence.

Quite apart from the fact that "turning the modem/router off for an hour always cleared stale sessions" is not true. As you say immediately afterwards:-

Unfortunately, in a lot of cases, it's still necessary to get Plusnet to kill the stale session.

What is this "pay" site I have seen mentioned a few time recently please?

Edited by RobertoS (Wed 26-Aug-15 15:42:43)

In reply to a post by AndyHCZ:

Mildly embarrassing.

I guess people from the 'pay' site also attend the monthly product group meetings with OR...

I bet they don't boast about having access to info, and then back-pedalling when asked to prove /back it up, unlike what you do,when claiming it to be fact, citing that it's that old cop out chestnut "commercially sensitive" info,
You i think post a lot of tripe!! in order to deliberately mislead people and disrupt things

Edited by tommy45 (Wed 26-Aug-15 17:08:25)

In reply to a post by RobertoS:

What is this "pay" site I have seen mentioned a few time recently please?

I don't know for sure what he means by PAY site, but he possibly means that because Kitz accepts voluntary donations from those that may wish to make a donation, nothing more ,it's in no way as he describes ,yet more misleading off topic, and disruptive comments from him This

Maybe he would like to clarify what exactly he means by PAY site or will he be unable to answer that too due to it being "commercially sensitive" information to discus on a public forum ?

Edited by tommy45 (Wed 26-Aug-15 17:51:03)

That was my feeling, and that it was a way of being derogatory about a particular site without specifically naming it, because he has no respect at all for it.

In reply to a post by RobertoS:

Disconnecting a modem from a line to most people means disconnecting the DSL cable at one end or the other. It doesn't mean causing a loss of sync by powering it down.

You are now playing on words where I have described a method. It's pointless arguing with you as you seem to refuse to see the wood for the trees.

In reply to a post by RobertoS:

You seem to completely misunderstand everything about the subject, and not realise that everyone you are disputing the issue with here knows an awful lot more than you. Considering your odd interpretation of the language in several places perhaps your misconceptions are to be expected.

Gabbling on about problems people have had in the past on Plusnet and Kitz forums is pointless, particularly if you were involved in giving incorrect advice.

Equally pointless seems to be trying to educate you, so I for one will give up. I shall merely try to help people I find you misinforming.

As you undoubtedly seem not to be an engineer, you are the one getting confused. I was NOT solely referring to "users problems" on the kitz site, but the wealth of CORRECT information that is there, from the experts, especially those in the field. I am quite willing to be "educated" but that would be by people who are the experts, not the non-engineers that seem to misinterpret what they choose. You seem to ignore the fact that there will be quite a few readers here that do not understand all the technical terms involved, and trying to explain things in a plain and simpler way is not "odd interpretation of the language", and it not always easy to do, sometimes things could be worded better.

In reply to a post by RobertoS:

However, before I go:-

Clicking Disconnect and powering off the Router should be done before even contemplating turning off the Modem

If you mean closing the PPP session, say so. Disconnecting means removing physical connections. It is possibly "best practice", but is rarely a necessity.

"Closing" a PPP session will mean little to most non-technical users. If you log into a Router with the ability in the PPP Interface, the button is marked DISCONNECT. It seems you again want to twist the interpretation.
It is "best practice" and the reason is to help reduce the possibility of a stuck stale session issue which can arise on occasion, and even the experts don't always know why.
If you wish to go round offering advice which is not "best practice" that is your choice.
Do NOT criticise me for choosing to give "best practice" advice.

In reply to a post by RobertoS:

If anyone is going to turn off their Modem, it should be turned off for at the very least 30 minutes and preferably a hour to ensure the sync loss doesn't get counted as a drop in connection and it resets some of the DLM counters.

Utter drivel.

It seems you can't be bothered to go and read up on it.

In reply to a post by RobertoS:

But it any event I'm not certain that turning off the modem will help resolve a stuck stale session.
Certainly on 20CN, turning off the Modem/Router for an hour always cleared stale sessions, and Plusnet gave similar advice for 21CN when they had quite a few stale session problems with those Network issues.

Everything you say after the first sentence of it contradicts that first sentence.

Quite apart from the fact that "turning the modem/router off for an hour always cleared stale sessions" is not true. As you say immediately afterwards:-

Unfortunately, in a lot of cases, it's still necessary to get Plusnet to kill the stale session.

Whilst I will agree that was badly worded, the first sentence was referring to FTTC, I think the meaning is clear. On 20CN because of the way PPP Authentication etc. is done, the action usually results in the stale session dying. 21CN is different and I can't be certain that it is always the case (I don't see, nor do I investigate all possible examples that might exist). The fact remains that in some situations, what you do as a user, does not result in the expected outcome. All attempts at different actions to get a stale session to die, fail. Then Plusnet need to kill it.

In conclusion, I don't intend to waste any more time on this simply because you choose not to give best practice advise on occasion, and twist what I was actually saying rather than try and understand what I did mean (despite some bad wording)

Bad wording means bad information.

what is this pay site you referring to?

whats embarrassing is openreach not knowing how to rollout g.inp on their own network. Which is living proof that you can attend 1000s of meetings and still not have a clue.

It's easy to be a keyboard warrior.

There are issues with retransmission (OR admit this to ISPs) - the latest one being with VoIP. But at the end of the day, they know a heck of a lot more than you or I ever will.

In reply to a post by ChrisAO:

In reply to a post by RobertoS:

If anyone is going to turn off their Modem, it should be turned off for at the very least 30 minutes and preferably a hour to ensure the sync loss doesn't get counted as a drop in connection and it resets some of the DLM counters.

Utter drivel.

It seems you can't be bothered to go and read up on it.

The DLM stuff that's on Kitz's site is pretty comprehensive - if the DLM uses MTBR (mean time between retrains) as an indicator of line stability, then simply turning the modem off/on again quickly shouldn't cause an issue - the DLM will see this as a one off. If you do this a couple of times in quick succession however, the DLM will factor it in to deciding what to do with the line.

The 30 minutes thing is a "better safe than sorry" approach to ensure the retrain isn't counted.

Whether this is anecdotal, based on fact or whatever, there is no official documentation from BT in the public domain AFAIK - just excerpts etc which I know Andy has posted details on in the past, since he got in to a slanging match with Kitz IIRC.

The stuck session thing appears to get mentioned on plus.net a fair bit - which is slightly amusing since a lot of plus.net people over on the community site seem to be able to tear down their PPP session multiple times every night, in pursuit of elusive lower pings & higher speed downloads... But it does indeed appear to get stuck at the plus.net end sometimes.

I just power off my router for a bit and leave the modem as is - no need to worry about 30 minutes when they're separate boxes.

@Andy - Kitz isn't a pay site any more than TBB or community.plus.net is.

In reply to a post by AndyHCZ:

The 'pay' site

False.
The site is not in any way shape or form a pay site, so stop that libellous & vindictive rumour that you are spreading.

makes a lot of misinterpretations about how DLM works based on the ASSIA v BT court case ruling,

False.
It was written prior to the ASSIA court case. None of the information on that page is assumed from or taken from any of the court case documentation.

particularly about how the data from the 15 min bins is analysed

BT collects the data from 15 min bins. This isnt just a BT thing, most routers store data in 15 min bins.
However, if you are still unsure you could always get your ISP to use the BRAT/RRT tool from KBD which will (if they have the correct permission) show the data recorded by the DLM system for KBD in 15 min units.

The fact is though that this 30 min thing is a complete myth and irrelevant to how RAMBo analyses the 24hr data.

False
Ive never said the 30 mins is anything to do with how RAMBo analyses the data at all.

I have said how they monitor for Wide Area Events, and that relies on uptime during that 15 min time frame. The 30 min is simply a precaution on how the DLM sees the retrain as a forced or unforced event.

The over-riding fact is that the system does allow 'x' retrains per day (depending upon your profile) and will turn a blind eye. But there are many examples whereby some users have been messing with a new router and they do exceed the MTBR so get caught by the DLM.

You don't have to wait 30 mins. I don't if I know Im going to be doing a straight swap that is only going to involve one or two resyncs. However if Im going to be messing with firmwares and configurations on a router, then I will.

It is a fact is every time you disconnect and resync in the same 15 min period then the MTBR counter will increase by 1. It is a fact that if there is a complete 15 min bin without any uptime then the the previous retrain event is classed as an unforced retrain.

Mildly embarrassing.

For you - spinning lies that aren't true.

I guess people from the 'pay' site also attend the monthly product group meetings with OR.

My information about DLM comes from BT Wholesale and information distributed to ISPs.
The DLM system was designed by and is owned by BT wholesale. RAMBo design and implementation. 'belongs' to BT Wholesale. Theres 3 sub-systems:- 20CN, 21CN & NGA.


Im sure Saffy knows and can confirm that I have always had BTw contacts there going back >12 years. Ive always made info available on my site, but just so you know both BT Openreach and BT Wholesale are fully aware of what's up there. In fact it was the BT CEO that encouraged and endorsed what I was doing.

Just because the information I get doesn't come from the same source within BT doesnt mean that you can constantly diss the information that I put out.

Some people (especially those on the "pay" site) are clearly jealous

False!
I am most certainly not jealous of you, nor do I want to be 'part of your circle' as was claimed on the PN forums. Ive been doing what I do for over 12 years and the info is put out there for all to read. Why on earth would I be jealous of you.

I don't go round stirring things up and talking to people in a condescending manner when they have a problem with their broadband refusing to believe that Openreach/BT/Plusnet may have got something wrong. I'm not the reason why people get wound up on the Plusnet forums.


Your problem Andy appears to be the fact that I do get info, and what you fail to comprehend is that what one department says isn't necessarily the same as what another says. Unlike you I know and accept that BT do on occasion stuff things up and everything doesnt go to plan. Its been happening for the past 13 years.

A classic example of this was G.INP when you refused to believe any of the info on my site, simply because it wasn't what Openreach was saying on the info you got. You sat there telling people that things 'were working as intended' and that 'it wasn't causing any detriment to how they used their connection'.

I on the other-hand knew something wasn't working how it should, I was the one sympathising with users who suddenly lost 10Mbps of speed and doubling of latency. I was the one who contacted certain people in BT/Plusnet/Router Manufacturers. I think it was only when you saw me tell Bob Pullen about the HH5A's on the PN forum and telling him to swap to a HH5B, that you shut up.

The information I had about G.INP was correct, despite you saying it was rubbish. This is one of the reasons why I got someone at Openreach to actually put their name to things. Im sure Andrew will confirm just how hard that is and how long it takes to go through that process as things are checked and double checked before you can publish.

If you want to say information is rubbish then take it up with BT not me. I put the information out there in the hope of helping people to get facts. You obviously seem to better than their Chief Engineer.
http://www.kitz.co.uk/adsl/ginp-retransmission.htm

--
edit - corrected typo for one place where I'd accidentally typo'd MTBR as MBTR

Edited by kitz (Fri 18-Sep-15 13:31:35)

In case anyone doubts the time frame and information about DLM on my site... and proof that Andy's defamatory comment about it being based on the ASSIA court case ruling is a lie:-

You can see its always been available to members of my site since May 2014. I never did get around to doing the graphic I intended, but after lots of requests I linked to it live without the graphics.
Ironically you can also see in that thread some input from cpettitt who wrote the one on Plusnet's site at about the same time.

Info about the DLM system was written prior to the DLM process and Ive always had some info about it. This was a 2006 version.

Just because AndyH doesnt get that info via Openreach does not mean its wrong. As mentioned the DLM system is BTwholesale's baby. The info that was available from BTw for the ISPs afaik was pulled at the time of the court case and locked down tight, which is why nothing else is available in the public domain now.

Thanks for that G.INP interview link kitz.