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Standard User jelv
(knowledge is power) Fri 26-Apr-13 12:19:14
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Sync lost on incoming call on 20CN Marconi exchange


[link to this post]
 
I have been chasing a fault with my line (which normally has absolutely minimal errors), whereby when there is an incoming call hundreds of errors are logged in seconds and if we don't answer the phone quickly enough it loses sync. I've now been told it is a 'feature' of Marconi exchanges and there is nothing that can be done about it - I just have to wait for the exchange to be upgraded to 21CN (or fibre).

The more the line is being used at the time, the more likely it is to drop. As I use VoIP on the line this situation is unacceptable.

Has anyone else come across this?

SamKnows shows 21 WBC for September, but the spreadsheet from BT Wholesale doesn't list the exchange - which is the more likely to be correct?

jelv

Plusnet user since November 2001

Edited by jelv (Fri 26-Apr-13 12:22:44)

Standard User yarwell
(sensei) Fri 26-Apr-13 12:44:56
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
that's not a feature of any ADSL that I've head of. As you said, normally you don't have many errors.

A line fault generating interference from the extra current perhaps, or a device at your end - filter refresh perhaps ?

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Standard User jelv
(knowledge is power) Fri 26-Apr-13 12:56:56
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: yarwell] [link to this post]
 
What has been eliminated:

All recent testing has been from the test socket.
Filter - several been tried - last engineer's visit I gained a filtered faceplate.
Routers - two TG582n's with three different firmware versions
Telephones - DECT and wired. However fault still occurs even if there is no phone plugged in at all!

Last visit the engineer disconnect my master socket and clipped his tester on to the bare incoming wires - still seeing CRC errors when the phone rang.

However the absolute killer fact is that he disconnected my line inside the exchange and connected his tester there - he still saw loads of CRC errors when the line was rung. That eliminates E side, D side and everything at my end.

They've done multiple lifts and shifts.

The response from BTw was that it's a known issue with Marconi 20CN exchanges and I have to lump it!

jelv

Plusnet user since November 2001


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Standard User jelv
(knowledge is power) Fri 26-Apr-13 13:05:59
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
From some bit loading charts I've seen from other users it looks like Marconi exchanges may not use downstream tones 33-36 which can reduce the maximum sync possible. I'm not seeing an 8128 sync and my attenuation is 21.5dB.

jelv

Plusnet user since November 2001
Standard User 4M2
(fountain of knowledge) Fri 26-Apr-13 13:25:29
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
I had that problem on 20CN and PN/OR never seemed to be able or willing to fix it - eventually the only fix was to switch to partial LLU frown

Edit: SFI inially did a "LIC change" (?) at the exchange which did help a little but after that nothing seemed to be done...

Edited by 4M2 (Fri 26-Apr-13 13:31:10)

Standard User yarwell
(sensei) Fri 26-Apr-13 14:50:56
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
perhaps the exchange end filter is the issue, though I would have tried a different breed of router in case something else hangs on better.

If they're saying it's the Marconi exchange does that change if you get 21CN broadband - did 21CN telephony go anywhere in the end ?

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Administrator MrSaffron
(staff) Fri 26-Apr-13 15:16:50
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: yarwell] [link to this post]
 
21CN broadband is a new DSLAM at the exchange end, just the 21CN telephony part of the roll-out is on hold

Andrew Ferguson, andrew@thinkbroadband.com
www.thinkbroadband.com - formerly known as ADSLguide.org.uk
The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User yarwell
(sensei) Fri 26-Apr-13 15:39:23
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
I'm confused - Marconi exchange or Marconi DSLAM ? Did BT use Marconi DSLAMs ? Fujitsu and Alacatel I remember from 10 years ago. Then the 21CN ones were Huawei I think.

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Standard User jelv
(knowledge is power) Fri 26-Apr-13 15:45:33
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: yarwell] [link to this post]
 
Can't answer that - all that's been said is 'Marconi exchange'

jelv

Plusnet user since November 2001
Standard User jelv
(knowledge is power) Fri 26-Apr-13 15:48:02
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: yarwell] [link to this post]
 
My exchange is 20CN only (with no LLU either).

jelv

Plusnet user since November 2001
Standard User yarwell
(sensei) Fri 26-Apr-13 15:50:27
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
hmm, there's certainly a lot of Marconi voice switch / exchange kit around in BT - the DSLAM isn't an exchange at all , though it lives in the exchange building.

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Standard User Zarjaz
(knowledge is power) Fri 26-Apr-13 17:42:49
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: 4M2] [link to this post]
 
A 'LIC change', so the 'port' that provides the voice has been shifted to a different port. The LIC is connected before ADSL equipment, so chances of it having any effect on the sync are slim to none. Have come across it once, but upon closer inspection it turned out to be a faulty splitter card in the 20cn DSLAM.

Standard User 4M2
(fountain of knowledge) Fri 26-Apr-13 18:03:52
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: Zarjaz] [link to this post]
 
In reply to a post by Zarjaz:
A 'LIC change', so the 'port' that provides the voice has been shifted to a different port. The LIC is connected before ADSL equipment, so chances of it having any effect on the sync are slim to none. Have come across it once, but upon closer inspection it turned out to be a faulty splitter card in the 20cn DSLAM.


I think the SFI was running out of ideas at the exchange, it was a Saturday afternoon job and after working on the problem for a couple of hours he had to pack in.

After that nothing was being done so I switched to partial LLU and the problem was solved smile
Standard User Zarjaz
(knowledge is power) Fri 26-Apr-13 19:38:37
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: 4M2] [link to this post]
 
After that nothing was being done so I switched to partial LLU and the problem was solved

So you kept the Btw LIC, and just had new LLU DSLAM ties ........... proving it wasn't the LIC, right ?

Standard User 4M2
(fountain of knowledge) Fri 26-Apr-13 19:59:27
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: Zarjaz] [link to this post]
 
In reply to a post by Zarjaz:
After that nothing was being done so I switched to partial LLU and the problem was solved

So you kept the Btw LIC, and just had new LLU DSLAM ties ........... proving it wasn't the LIC, right ?


It seems that way...

But I never did find out what the actual problem was, Plusnet closed the ticket and I found it impossible to get any information from them or get them to request OR to investigate further, also there wasn't a voice fault as such so BT wouldn't do anything. Lost patience with Plusnet and, as I wasn't in a contract, went to partial LLU and kept the line with BT smile
Standard User jelv
(knowledge is power) Fri 26-Apr-13 21:55:47
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: 4M2] [link to this post]
 
What were your sync speeds (down and up)? I'm finding that although the attenuation says I should easily get 8128/832 I never get above 7808. Looking at the bit/tone allocation, tones 33-36 are not being used.

jelv

Plusnet user since November 2001
Standard User 4M2
(fountain of knowledge) Fri 26-Apr-13 23:50:32
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
This was when I had the problems during October 2011: http://farm9.staticflickr.com/8526/8684848940_cf1d45...

Hope it's revelant smile

Edit: and a RS graph http://farm7.staticflickr.com/6235/6279314911_3a32b5... from about the same time showing the effect of incoming phone calls - each after approx 6 rings of the phone frown

Edited by 4M2 (Fri 26-Apr-13 23:58:09)

Standard User jelv
(knowledge is power) Sat 27-Apr-13 00:32:08
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: 4M2] [link to this post]
 
Relevant? I'll say so. That exactly mirrors what I'm seeing right down to the bigger than normal gap between the upstream and downstream.

If the exchange had another DSLAM that was not Marconi a transfer on to that would have cured the problem.

jelv

Plusnet user since November 2001

Edited by jelv (Sat 27-Apr-13 00:33:43)

Standard User 4M2
(fountain of knowledge) Sat 27-Apr-13 01:00:46
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
What are you going to do? Unlike you I had the option of switching to partial LLU which was much less troublesome for me than trying to get OR and PN back onto the case. Eventually Bob Pullen responded to my calls for help but by that time it was too late since I had already left PN frown
Standard User Fosterthiele
(newbie) Sat 27-Apr-13 08:25:04
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Re: Sync lost on incoming call on 20CN Marconi exchange *DELETED*


[re: 4M2] [link to this post]
 
Post deleted by Sadoldman

Edited by Fosterthiele (Sat 27-Apr-13 08:25:34)

Standard User jelv
(knowledge is power) Sat 27-Apr-13 08:50:02
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: 4M2] [link to this post]
 
Some exchanges have DSLAMS from different manufacturers. I've asked PN to find out if that is the case with my exchange - if it is a lift and shift would fix it. If I was with an ISP that would fight my cause with BT to demand they fix it I might stand a chance of a satisfactory outcome, with Plusnet I fear there's no chance of that whatsoever - I'm just having to decide which of two compromises I'm going to have to take.

What shook me was that an ISP as large as Plusnet was unaware of the specifics of this issue (and nothing I've had back from them indicates that they are aware even now). Instead I had a complete diagnosis within 15 minutes of contacting another ISP with a reputation for fixing issues and that also stands no nonsense from BT.

jelv

Plusnet user since November 2001
Standard User Zarjaz
(knowledge is power) Sat 27-Apr-13 09:32:42
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
Some exchanges have DSLAMS from different manufacturers. I've asked PN to find out if that is the case with my exchange - if it is a lift and shift would fix it.

Sadly, not true. A lift and shift won't get you on to the other suppliers equipment, it'll be a new port on the same stuff, *maybe* another card.

You would need a cease and reprovide.
Instead I had a complete diagnosis within 15 minutes of contacting another ISP with a reputation for fixing issues and that also stands no nonsense from BT.

A and A perchance ?

Standard User 4M2
(fountain of knowledge) Sat 27-Apr-13 11:45:46
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
One thing that I didn't mention about my line fault was it developed over time: for years the DSL wasn't affected by incoming calls, then towards the end of 2011 six or more rings of the phone would cause the DSL to drop and the router would resync almost immediately. Plusnet never "saw" these disconnections because they were so short and that made it really difficult to get anything done about it.

Also, at that time, the ticketing system at PN meant that adding to a ticket that hadn't been responded to by PN staff put the case to the back of the queue - this obviously made the whole experience incredibly frustrating!

Edit: Anyway a valuable lesson was learnt by me: to never get into a contract with an ISP for BB - a minimum term gives one more options, sadly for you though your choice is only based on 20CN kit (ADSL MAX) at the exchange...

Edited by 4M2 (Sat 27-Apr-13 12:07:02)

Standard User jelv
(knowledge is power) Sat 27-Apr-13 15:04:53
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Re: Sync lost on incoming call on 20CN Marconi exchange *DELETED*


[re: 4M2] [link to this post]
 
Post deleted by jelv
Standard User jelv
(knowledge is power) Sat 27-Apr-13 15:07:58
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: 4M2] [link to this post]
 
I know all about short drops of sync where the PPP does not drop. When that happens nothing appears in the radius logs so Plusnet then reply to the ticket saying something like
I have retested your line and can see the connection has been stable for over 3 days
Which prompts posts like this: http://community.plus.net/forum/index.php/topic,1130...

Nine days after that post I get
Thank you for getting back to us. I have been testing your connection and the broadband has been stable for 3 days which is good news
And another four days later I get
Unfortunately our testing has not revealed any condition on your line that would confirm the details of the issue as you have reported them. Our connectivity checker has not even been able to see the drops in connection on the 11th that you reported.
I'll leave you to image what my response to those was!

I raised this fault on 20th March. The information from Plusnet still doesn't tell the whole story which I learnt from another ISP within 15 minutes as posted here.

jelv

Plusnet user since November 2001

Edited by jelv (Sat 27-Apr-13 15:12:59)

Standard User 4M2
(fountain of knowledge) Sat 27-Apr-13 16:09:39
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
I can fully understand your frustration with PN about this - I had a very similar experience...possibly it's now time for you to walk away?
Standard User jelv
(knowledge is power) Wed 08-May-13 14:26:59
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
Well thanks to the information provided to me by Andrews and Arnold I seem to have reached a resolution of sorts; it was they who told me that this issue affected Max Premium users only. Following a point of Plusnet having no further ideas I requested a downgrade to standard Max and the issue has gone away.

jelv

Plusnet user since November 2001 - not sure for how much longer
Standard User yarwell
(sensei) Wed 08-May-13 14:47:49
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
thans for the update. Related to lower SNR margin on the upstream perhaps ?

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Standard User jelv
(knowledge is power) Wed 08-May-13 15:24:13
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: yarwell] [link to this post]
 
The upstream margin was around 15 on Max Premium - that should have been enough!

jelv

Plusnet user since November 2001 - not sure for how much longer
Standard User 4M2
(fountain of knowledge) Wed 08-May-13 16:22:25
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
In reply to a post by jelv:
Well thanks to the information provided to me by Andrews and Arnold I seem to have reached a resolution of sorts; it was they who told me that this issue affected Max Premium users only.


That's really interesting because it was after I had the ADSL MAX upstream uncapped that I started to have problems caused by incoming calls when I was with Plusnet. Upstream SNRM was 21dB on 448K then SNRM reduced to 12dB on 832K.
Standard User jelv
(knowledge is power) Wed 19-Jun-13 08:49:22
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
To wrap this up: my line is now uber stable since I changed to ADSL Max instead of Max Premium. Currently the line has been in sync for nearly 4 weeks with no drops whatsoever:

Up time (Days hh:mm:ss): 27 days, 10:31:45
xDSL Standard: ITU-T G.992.1
xDSL Annex: Annex A
Channel Mode: Fast

Downstream

Noise Margin: 6.0 dB
Bandwidth: 7616 kbps
Attenuation: 21.0 dB
Power: 19.9 dBm

Errors:
FEC: 0
CRC: 177
HEC: 295

Failures since last reset:
LOF: 0
LOS: 0
LPR: 0
ES : 155

Upstream

Noise Margin: 23.0 dB
Bandwidth: 448 kbps
Attenuation: 14.0 dB
Power: 12.0 dBm

Errors:
FEC: 4
CRC: 242
HEC: N/A

Interesting that another side effect of the excrementy Marconi exchange is that I can't get the full 8192 sync in spite of the stats showing clearly it should be possible.

Edit: Replacement of censored word

jelv

Plusnet user since November 2001 - not sure for how much longer

Edited by jelv (Wed 19-Jun-13 08:51:52)

Standard User XRaySpeX
(eat-sleep-adslguide) Wed 19-Jun-13 09:56:16
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
In reply to a post by jelv:
that I can't get the full 8192 sync in spite of the stats showing clearly it should be possible.
Could be you are on Interleaved despite the "Channel Mode: Fast" if that's a Netgear router. Is there a "D:" line in those stats?

1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 20 Meg WBC
Standard User yarwell
(sensei) Wed 19-Jun-13 10:23:22
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
Noise Margin: 6.0 dB - seems like you can't get 8128 'cos of that.

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Standard User jelv
(knowledge is power) Wed 19-Jun-13 10:47:13
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: yarwell] [link to this post]
 
I think the noise margin is the average across the tones actually in use. Marconi 20CN exchanges don't use all the possible ADSL1 tones.

jelv

Plusnet user since November 2001 - not sure for how much longer
Standard User yarwell
(sensei) Wed 19-Jun-13 13:43:30
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
I do wish you would stop calling the DSLAM an exchange wink

I get 8128, the vendor code on the DSLAM is TSTC which is TI is that a Marconi DSLAM ? I only get 7616 with some routers, on account of being interleaved and requiring S=1/2 to get the full tilt on 36.5 dB attenuation.

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Standard User jelv
(knowledge is power) Wed 19-Jun-13 15:05:22
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: yarwell] [link to this post]
 
Sorry - I stand corrected. You are quite right, some exchanges have a mixture of DSLAM suppliers (mine apparently doesn't frown ).

Yet another 'feature' of these DSLAMs appears to be that they don't return a vendor code. I'm on Fastpath (in case you hadn't deduced that from the stats).

jelv

Plusnet user since November 2001 - not sure for how much longer
Standard User yarwell
(sensei) Wed 19-Jun-13 15:33:34
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
http://www.kitz.co.uk/adsl/linestats_explanation.htm suggests Marconi is the TSTC chipset. Not all routers report remote chipsets either !

Seems an odd coincidence yours landed at exactly 7616 on Fastpath

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics
Standard User jelv
(knowledge is power) Wed 19-Jun-13 18:17:35
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: yarwell] [link to this post]
 
I wonder is there is more than one model/version of Marconi DSLAM?

I don't like coincidences, but as the line is now so stable and is fast enough to stream BBC iPlayer HD I'm not messing about any more.

jelv

Plusnet user since November 2001 - not sure for how much longer
Standard User RobertoS
(sensei) Wed 19-Jun-13 21:51:21
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
Strange that you have upstream FECs but not downstream. I have never seen upstream interleaving enabled on BT Wholesale circuits.

As XRaySpeX says, it would be useful to know the D: line in the router stats, and whether or not it is a Netgear.

POI - BT Wholesale version of G.992.1 is capped at 8128kbps, not 8192kbps. O2/Be LLU allows the full whack, I don't know about other LLUs.

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 53.4/16.8Mbps @ 600m. - BQM

"Where talent is a dwarf, self-esteem is a giant." - Jean-Antoine Petit-Senn.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Allergy information: This post was manufactured in an environment where nuts are present. It may include traces of understatement, litotes and humour.

Edited by RobertoS (Wed 19-Jun-13 21:53:20)

Standard User jelv
(knowledge is power) Wed 19-Jun-13 22:35:24
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: RobertoS] [link to this post]
 
This I think the relevant bit I see in RouterStats (it's a TG582 router):

System Vendor info (showtime): Local Remote
Country code: 0F00 0000
ID: TMMB ----
Specific: 3C61 0000

jelv

Plusnet user since November 2001 - not sure for how much longer
Standard User jelv
(knowledge is power) Mon 28-Nov-16 08:01:53
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
I've just come back to this topic and realised the story is incomplete.

I went back to AAISP to say I'd been told there was only Marconi in my exchange. They said no it isn't so I went back to Plusnet. They eventually managed to get me shifted to the alternative equipment and back on Max Premium - no more disconnects when the phone rang (and the strange gap between the upstream and downstream tones disappeared).

Plusnet 1/10
AAISP 10/10

jelv

AAISP November 2016
(Previous ISP Plusnet November 2001 to October 2016)
Telephone rental: Pulse8
Standard User Zarjaz
(eat-sleep-adslguide) Mon 28-Nov-16 18:17:13
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Re: Sync lost on incoming call on 20CN Marconi exchange


[re: jelv] [link to this post]
 
Any chance of an honourable mention too ?

I had the answers the day after your first post.

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