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Standard User rogerh
(committed) Sat 14-Sep-13 13:43:51
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Interleaving on ADSL Max


[link to this post]
 
I have a long, unstable line which was actually helped when ADSL Max came in, as it allows sync down to 160bps downstream. For a long time the profile was set by BT's automated system (the name of which I forget) to include interleaving. This is probably a good thing? However, for the last year or two it has invariably set as Fast Path. When I asked my ISP (now assimilated into Talktalk Business) to change the profile to interleaved, they said they could not do this as it was entirely under the control of BT's automatic system.

Now I was aware that some people who preferred Fast Path for latency reasons were upset in the past as this was automatically changed to interleaved, but I was unaware of the opposite change being automatically applied. Are Talktalk right (it had to happen sometime ...)? Or is there any advantage to Fast Path I haven't thought of, such as allowing lower sync speeds?

I thought I would ask the experts here to get my facts straight, before perhaps taking it up in an ISP forum.

Many thanks

Roger
Standard User RobertoS
(sensei) Sat 14-Sep-13 14:17:11
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Re: Interleaving on ADSL Max


[re: rogerh] [link to this post]
 
Your ISP is talking rubbish.

The BT Wholesale DLM (Dynamic Line Management) can be set to Auto or Interleaved, that being a setting the ISP can select. Normally at initial setup time. IIRC it can also be set to Fast Path, but in severe problem cases it will still switch to Interleaved.

Once it is set, or switches to, interleaved it never automatically switches back to Fast Path.

You say your ISP is now part of TalkTalk Business. Is TalkTalk present at your exchange? Samknows is the best place to check, using your phone number. If you post the URL of the result that would be best for us.

Does this checker recognise your phone number, and is so what does it say please?

Finally, does the BT Performance Checker work for you? If it does, can you continue from the initial results to the Further Diagnostics near the bottom of the page. Then copy and paste the contents of the two results text boxes smile.

The above will confirm whether you are still on a BT Wholesale service in the first place, and give us useful diagnostics if you are.

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 51.8/16.8Mbps @ 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.
Standard User rogerh
(committed) Sat 14-Sep-13 14:25:30
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Re: Interleaving on ADSL Max


[re: RobertoS] [link to this post]
 
Only BT is present at my exchange, and that reluctantly! The last few nights the POTS line has been going down for an hour or so at 1am, I think they reckon rural people don't use the phone at night. (not relevant to current issue) WNCER


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Standard User 4M2
(knowledge is power) Sat 14-Sep-13 14:33:46
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Re: Interleaving on ADSL Max


[re: rogerh] [link to this post]
 
In reply to a post by rogerh:
I have a long, unstable line which was actually helped when ADSL Max came in, as it allows sync down to 160bps downstream. For a long time the profile was set by BT's automated system (the name of which I forget) to include interleaving. This is probably a good thing? However, for the last year or two it has invariably set as Fast Path. When I asked my ISP (now assimilated into Talktalk Business) to change the profile to interleaved, they said they could not do this as it was entirely under the control of BT's automatic system.


I think that I have heard that once a line is changed from interleaved to fastpath, usually manually by an ISP, some(?) ISP's can not manually reverse it back to interleaved.
Standard User rogerh
(committed) Sat 14-Sep-13 14:34:18
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Re: Interleaving on ADSL Max


[re: rogerh] [link to this post]
 
Speedtest: DL 0.01, UL 0.00, Latency 38.38ms Further diagnostics: "an error occurred" and a suggestion to rerun test. Not very helpful I know, but this is a rather marginal line. Officially condemned as unusable by BT.
Standard User rogerh
(committed) Sat 14-Sep-13 14:36:20
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Re: Interleaving on ADSL Max


[re: 4M2] [link to this post]
 
Is that "can't" or "won't", I can see them not wanting to be bothered? But I certainly never asked them to change it in the first place.
Standard User jelv
(knowledge is power) Sat 14-Sep-13 15:26:55
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Re: Interleaving on ADSL Max


[re: rogerh] [link to this post]
 
In reply to a post by rogerh:
When I asked my ISP (now assimilated into Talktalk Business) to change the profile to interleaved, they said they could not do this as it was entirely under the control of BT's automatic system.
I suggest that finding you are using an ISP whose support haven't a clue what they are talking about on such a basic matter is a strong hint to change ISP!

jelv

Plusnet user since November 2001 - not sure for how much longer
Standard User RobertoS
(sensei) Sat 14-Sep-13 15:53:05
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Re: Interleaving on ADSL Max


[re: jelv] [link to this post]
 
They'll have been trained only on TalkTalk LLU, with just a rudimentary briefing on the BT Wholesale option they under-provision.

Which explains it, but is far from an acceptable excuse by the company.

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 51.8/16.8Mbps @ 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.
Standard User 4M2
(knowledge is power) Sat 14-Sep-13 16:44:17
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Re: Interleaving on ADSL Max


[re: rogerh] [link to this post]
 
Xilo/uno TTB partial LLU:

"Broadband Interleaving

New lines are set to 'Auto' which is our recommended setting.

If interleaving has been applied due to poor line conditions, we can remove this to lower latency for gaming by setting 'Opt Out' or if you would like better stability over latency, please set to 'Opt In'.

[If] We are unable to determine the current status of interleaving on your line.

If you would like to make a change, please complete the form below and your request will be actioned manually."

Edited by 4M2 (Sat 14-Sep-13 16:54:26)

Standard User yarwell
(sensei) Sat 14-Sep-13 18:18:23
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Re: Interleaving on ADSL Max


[re: 4M2] [link to this post]
 
In reply to a post by 4M2:
New lines are set to 'Auto' which is our recommended setting.

If interleaving has been applied due to poor line conditions, we can remove this to lower latency for gaming by setting 'Opt Out' or if you would like better stability over latency, please set to 'Opt In'.


Opt in would be appropriate on a very long line.

--

Phil

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

MaxDSL diagnostics
Standard User XRaySpeX
(eat-sleep-adslguide) Sat 14-Sep-13 18:22:37
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Re: Interleaving on ADSL Max


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
The BT Wholesale DLM (Dynamic Line Management) can be set to Auto or Interleaved, that being a setting the ISP can select.
BTw may very well offer that feature to ISPs but not all ISPs take it up (can't be bothered!), EE for 1. Pretty sure EE leaves interleaving entirely in hands of DLM.
In reply to a post by RobertoS:
Once it is set, or switches to, interleaved it never automatically switches back to Fast Path.
Don't think that can be right! Few weekends ago my Fast Path connection went bad, discons, wildly oscillating NM & speed (suspect some BT eng messing about at exchange or cab) but still usable. DLM compensated by applying Interleaving. Didn't bother reporting it to EE as expected it would right itself. Come Mon. connection became solid again. Later that day or next, Fast Path reinstated itself.

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) Sat 14-Sep-13 18:24:12
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Re: Interleaving on ADSL Max


[re: XRaySpeX] [link to this post]
 
Auto is auto, and I would expect it to go both ways. Opt-out and Opt-in cover the alternative scenarios.

--

Phil

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

MaxDSL diagnostics
Standard User XRaySpeX
(eat-sleep-adslguide) Sat 14-Sep-13 18:24:48
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Re: Interleaving on ADSL Max


[re: 4M2] [link to this post]
 
That's LLU, but OP only has BTw ADSL Max available.

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 4M2
(knowledge is power) Sat 14-Sep-13 18:32:23
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Re: Interleaving on ADSL Max


[re: yarwell] [link to this post]
 
In reply to a post by yarwell:
In reply to a post by 4M2:
New lines are set to 'Auto' which is our recommended setting.

If interleaving has been applied due to poor line conditions, we can remove this to lower latency for gaming by setting 'Opt Out' or if you would like better stability over latency, please set to 'Opt In'.


Opt in would be appropriate on a very long line.


Sure smile Matt at uno certainly recommended that I stay on interleaved after it was auto-selected even on a ADSL2+ 37dB downstream attenuation and 6dB SNRM.

Would ADSL MAX fair better than ADSL2+ on fastpath with the same line length and a stable 6dB SNRM?
Standard User yarwell
(sensei) Sat 14-Sep-13 18:38:43
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Re: Interleaving on ADSL Max


[re: 4M2] [link to this post]
 
In reply to a post by 4M2:
Would ADSL MAX fair better than ADSL2+ on fastpath with the same line length and a stable 6dB SNRM?
37 dB ? No, I get >9M downstream at that which G.dmt cannot do.

--

Phil

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

MaxDSL diagnostics
Standard User RobertoS
(sensei) Sat 14-Sep-13 19:28:35
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Re: Interleaving on ADSL Max


[re: XRaySpeX] [link to this post]
 
WBC DLM may be able to switch back, particularly in its recent incarnation where IP Profile no longer goes in steps. It didn't when the ADSL2+ Mbps steps were in force.

I was describing ADSL Max 20CN DLM behaviour, where it definitely did not switch away from interleaved once imposed. The "Auto" applied only to turning it on, or else the criteria for reinstating Fast Path were far too stringent. It never happened for anyone on these forums.

The OP is probably on IPSC G.DMT and that still has stepped IP Profiles within the WBC DLM. The Fast Path v Interleaving behaviour for IPSC I accept is open to question.

He could still be on ADSL Max couldn't he?

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 51.8/16.8Mbps @ 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.
Standard User XRaySpeX
(eat-sleep-adslguide) Sat 14-Sep-13 20:02:33
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Re: Interleaving on ADSL Max


[re: RobertoS] [link to this post]
 
Yes, sorry, you were describing old ADSL Max DLM.

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 rogerh
(committed) Sat 14-Sep-13 20:21:57
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Re: Interleaving on ADSL Max


[re: RobertoS] [link to this post]
 
I don't think we have got 21C anything. My connection is still on ADSL Max AFAIK. Talktalk keep telling me they are going to put me on a "new and better" product in six months but this is just wishful thinking on their part.
Standard User rogerh
(committed) Sat 14-Sep-13 20:27:30
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Re: Interleaving on ADSL Max


[re: yarwell] [link to this post]
 
This is my suspicion, that someone at Talktalk has opted me in to Fast Path at some stage. For about 5 years (and before that on ADSL500) the connection was always interleaved: for 2 or 3 years it has been always Fast Path. Despite the downstream sync varying from 160 to 800 and something, and upstream usually being about 300 to 448.

Are there any additional limitations on sync speed with interleaving?
Standard User RobertoS
(sensei) Sat 14-Sep-13 22:12:41
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Re: Interleaving on ADSL Max


[re: rogerh] [link to this post]
 
In reply to a post by rogerh:
Are there any additional limitations on sync speed with interleaving?
No. (Except on ADSL Max if you sync at 8128kbps on Fast Path then on Interleaved you more often than not only sync at 7616kbps).

The whole point of interleaving is to improve throughput speed (including speed test speed) at any given sync speed, but at the cost of a few milliseconds latency. On your line you need interleaving.

I have this basic description, and at the that bottom of that page is a link to Kitz's more detailed explanation of how it works.

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 51.8/16.8Mbps @ 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.
Standard User 4M2
(knowledge is power) Sat 14-Sep-13 22:52:17
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Re: Interleaving on ADSL Max


[re: RobertoS] [link to this post]
 
Particularly relevant to the OP might be that on a long line fastpath can actually be slower than interleaved since there may have to be excessive re-transmission of packets due to a greater likelihood of the packets being corrupted by noise?
Standard User rogerh
(committed) Sat 14-Sep-13 23:31:00
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Re: Interleaving on ADSL Max


[re: 4M2] [link to this post]
 
Thanks, everyone, for confirming my ideas. I shall now have to get back to Talktalk and see how far I get!

Roger
Standard User RobertoS
(sensei) Sun 15-Sep-13 00:17:28
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Re: Interleaving on ADSL Max


[re: 4M2] [link to this post]
 
tongue smile
The whole point of interleaving is to improve throughput speed (including speed test speed) at any given sync speed


My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 51.8/16.8Mbps @ 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.
Standard User 4M2
(knowledge is power) Sun 15-Sep-13 14:33:13
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Re: Interleaving on ADSL Max


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
tongue smile
The whole point of interleaving is to improve throughput speed (including speed test speed) at any given sync speed


Can interleaving depth also have an effect on sync speed?

On my partial LLU connection I can sync anywhere between ~12500Kbps and ~13500Kbps on a 6dB SNRM (37dB attenuation.) The TG585 v7 router does not indicate interleaving nor it's depth but I certainly get fewer FEC down errors at ~12500Kbps than at ~13500Kbps. I tend not to take any note of output power up/down but I think it stays at 12dBm and 19dBm. Obviously when there are differences in sync speed (down bandwidth) there are corresponding differences in throughput speeds...
Standard User RobertoS
(sensei) Sun 15-Sep-13 15:04:18
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Re: Interleaving on ADSL Max


[re: 4M2] [link to this post]
 
No. The interleaving depth is probably the same at both sync's, the sync varying depending on line conditions at the time you connect.

Lower errors are an expected result of lower sync speed. That's why bumping up the sync-time noise margin is the standard fix on BT Wholesale DLMs. A higher sync-time SNRM lowers the sync speed, so lowers the error rates, which is what the DLM wishes to achieve.

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 51.8/16.8Mbps @ 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.
Standard User 4M2
(knowledge is power) Sun 15-Sep-13 15:29:20
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Re: Interleaving on ADSL Max


[re: RobertoS] [link to this post]
 
Sync time SNRM's are always very close to 6dB though (according to the router log) would a difference of 0.5dB on the reported SNRM equate to a variation of ~1000Kbps in sync speed on a 37dB attenuation?

Edited by 4M2 (Sun 15-Sep-13 15:30:44)

Standard User RobertoS
(sensei) Sun 15-Sep-13 15:58:16
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Re: Interleaving on ADSL Max


[re: 4M2] [link to this post]
 
Sync-time SNRMs are by definition always close to the current parameter setting in the DLM. What is different, and causes sync speeds to differ between sync's, is the SNR.

See my website description of the process smile.

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 51.8/16.8Mbps @ 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 (Sun 15-Sep-13 15:58:43)

Standard User 4M2
(knowledge is power) Sun 15-Sep-13 16:18:01
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Re: Interleaving on ADSL Max


[re: RobertoS] [link to this post]
 
Thanks Bob, but I don't know what my SNR is smile

Perhaps I got confused when with ADSL Max there can be a reduction in sync speed:

Your website "Connection speed may or may not be affected, but on ADSL Max if the line can connect at 8128kbps on Fast Path this is usually reduced to 7616kbps. A few combinations of modem/router and exchange DSLAM can still achieve the full 8128kbps even with interleaving, particularly TI chipset-based."

And Kitz: "It should also be pointed out that whilst BTw state that applying interleaving shouldn't reduce your line speed, it does reduce the maximum line rate achievable from 8128kbps to 7616kbps due to the additional overhead required for check bytes.
Note: although BT state 7616 is maximum sync speed with interleaving, many instances of higher sync speeds have been reported by users. This is dependent upon your router being able to support S=1/2 mode which effectively combines two RS code words into a larger logical code word of 510 bytes (ANSI T1.413).

Interleaving and Error Correction are always switched on at the same time and the 7616 profile has a 512kbps error correction overhead with an increased latency of around 16 ms.
Whilst Interleaving on its own may not reduce your maximum sync speed, Forward Error Correction can and does affect your maximum sync rate."

Edited by 4M2 (Sun 15-Sep-13 16:23:03)

Standard User RobertoS
(sensei) Sun 15-Sep-13 16:41:26
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Re: Interleaving on ADSL Max


[re: 4M2] [link to this post]
 
Very rare to be able to find out the SNR, but it is that which changes all the time. SNRM just tells you how much it is changing, and is reset at every sync.

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 51.8/16.8Mbps @ 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.
Standard User 4M2
(knowledge is power) Sun 15-Sep-13 17:13:40
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Re: Interleaving on ADSL Max


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
Very rare to be able to find out the SNR, but it is that which changes all the time. SNRM just tells you how much it is changing, and is reset at every sync.


So in other words: a variation in SNRM whilst a router is sync'd to the exchange can be seen as an indication in the variation of SNR that is happening all the time since there is a default SNRM. Thus sync speed would be calculated according to the SNR at sync time together with a further reduction in sync speed corresponding to the default noise margin.

Returning to the Forward Error Correction/interleaving topic: are FEC errors reported by a router an indication of interleaving depth?
Standard User RobertoS
(sensei) Sun 15-Sep-13 20:19:29
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Re: Interleaving on ADSL Max


[re: 4M2] [link to this post]
 
In reply to a post by 4M2:
Returning to the Forward Error Correction/interleaving topic: are FEC errors reported by a router an indication of interleaving depth?
Too deep for me, that. Basically the greater the interleaving depth, the more uncorrected errors would become "corrected", but latency would increase.

Up to the point where the remaining errors are uncorrectable.

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 51.8/16.8Mbps @ 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.
Standard User yarwell
(sensei) Mon 16-Sep-13 19:52:11
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Re: Interleaving on ADSL Max


[re: 4M2] [link to this post]
 
the bandwidth for the extra data (for the error correction) has to come from somewhere I guess.

--

Phil

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

MaxDSL diagnostics
Standard User RobertoS
(sensei) Mon 16-Sep-13 23:26:42
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Re: Interleaving on ADSL Max


[re: yarwell] [link to this post]
 
Tut Phil! That's nothing to do with the sync speed, merely the way the bits are used. And as the whole point of interleaving is to increase the throughput for a given sync, by reducing the number of retransmissions required ....

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 51.8/16.8Mbps @ 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.
Standard User yarwell
(sensei) Thu 19-Sep-13 07:35:01
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Re: Interleaving on ADSL Max


[re: RobertoS] [link to this post]
 
Tut Phil! That's nothing to do with the sync speed, merely the way the bits are used.
But why does 8128 fast path often drop to 7616 interleaved ?

--

Phil

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

MaxDSL diagnostics
Standard User RobertoS
(sensei) Thu 19-Sep-13 11:51:50
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Re: Interleaving on ADSL Max


[re: yarwell] [link to this post]
 
Don't forget with there is a setting that allows the full 8128 on interleaved, given appropriate hardware and firmware. Just that most combinations don't have that setting available in both parts.

We may as well ask why ADSL Max has a maximum sync of 8128kbps, not 8192kbps.

In fact it was frequently reported that on O2/Be, interleaving could increase sync. Presumably because it was applied at (real) training time and reduced the error rates, so allowing a higher speed to be negotiated.

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 51.8/16.8Mbps @ 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 (Thu 19-Sep-13 12:05:19)

Standard User adslmax
(knowledge is power) Thu 19-Sep-13 12:56:51
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Re: Interleaving on ADSL Max


[re: RobertoS] [link to this post]
 
BT could easily put 8888K on it. (instead of 8128K or 8192K) but it alway's will be 8128K or 7616K (with interleaved)

plusnetADSL2+15.7 Meg
Standard User 4M2
(knowledge is power) Thu 19-Sep-13 13:18:48
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Re: Interleaving on ADSL Max


[re: adslmax] [link to this post]
 
In reply to a post by adslmax:
BT could easily put 8888K on it. (instead of 8128K or 8192K) but it alway's will be 8128K or 7616K (with interleaved)


Perhaps the IP Profiling system on G.DMT will only work on speeds up to 8128Kbps and there wouldn't be any advantage in having a faster downstream sync speed?
Standard User adslmax
(knowledge is power) Thu 19-Sep-13 14:40:52
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Re: Interleaving on ADSL Max


[re: 4M2] [link to this post]
 
In reply to a post by 4M2:
In reply to a post by adslmax:
BT could easily put 8888K on it. (instead of 8128K or 8192K) but it alway's will be 8128K or 7616K (with interleaved)


Perhaps the IP Profiling system on G.DMT will only work on speeds up to 8128Kbps and there wouldn't be any advantage in having a faster downstream sync speed?


BT can increasing IP Profile no problem. But, they wouldn't do it. They put a cap on 7150K out of 8128K.

plusnetADSL2+15.7 Meg
Administrator MrSaffron
(staff) Thu 19-Sep-13 14:44:18
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Re: Interleaving on ADSL Max


[re: adslmax] [link to this post]
 
Explain?

Or do the ATM to IP overheads not mean anything?

Andrew Ferguson, [email protected]
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 4M2
(knowledge is power) Thu 19-Sep-13 14:51:28
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Re: Interleaving on ADSL Max


[re: MrSaffron] [link to this post]
 
Is the IP Profile a means of limiting throughput speed also - no point in allocating a 8128Kbps bandwidth to a line that can not handle that speed, so perhaps, in a sense, the IP Profile is a cap?
Administrator MrSaffron
(staff) Thu 19-Sep-13 15:42:41
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Re: Interleaving on ADSL Max


[re: 4M2] [link to this post]
 
The 8128 Kbps bandwidth is for carrying 53 byte packets of data, which actually carry a 48 byte IP payload.

Now do the maths.

Andrew Ferguson, [email protected]
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 4M2
(knowledge is power) Thu 19-Sep-13 16:54:14
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Re: Interleaving on ADSL Max


[re: MrSaffron] [link to this post]
 
In reply to a post by MrSaffron:
The 8128 Kbps bandwidth is for carrying 53 byte packets of data, which actually carry a 48 byte IP payload.

Now do the maths.


8128Kbps - 635Kbps = 7493Kbps when headers are subtracted? smile
Standard User jelv
(knowledge is power) Thu 19-Sep-13 17:32:16
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Re: Interleaving on ADSL Max


[re: adslmax] [link to this post]
 
My current 20CN ADSL Max Premium stats:

Noise Margin: 6.6 dB
Bandwidth: 8128 kbps
Attenuation: 20.5 dB
Power: 19.9 dBm

Errors:
FEC: 479
CRC: 13
HEC: 140

As you can see I'm on interleaved as I have FEC errors and have a full 8128 sync.

jelv

Plusnet user since November 2001 - not sure for how much longer
Administrator MrSaffron
(staff) Thu 19-Sep-13 17:35:17
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Re: Interleaving on ADSL Max


[re: 4M2] [link to this post]
 
8128 Kbps or 153 packets per second

153 packets carry an IP payload of 153*48=7344 Kbps

So yes potential for a massive improvement of around 3%. Those with WBC will seen these improvements already of course due to the dynamic IP Profile.

Andrew Ferguson, [email protected]
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 4M2
(knowledge is power) Thu 19-Sep-13 17:54:37
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Re: Interleaving on ADSL Max


[re: MrSaffron] [link to this post]
 
In reply to a post by MrSaffron:
8128 Kbps or 153 packets per second


Please explain how you calculated a figure of 153 packets per second?
Standard User adslmax
(knowledge is power) Thu 19-Sep-13 19:26:27
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Re: Interleaving on ADSL Max


[re: 4M2] [link to this post]
 
In reply to a post by jelv:
My current 20CN ADSL Max Premium stats:

Noise Margin: 6.6 dB
Bandwidth: 8128 kbps
Attenuation: 20.5 dB
Power: 19.9 dBm

Errors:
FEC: 479
CRC: 13
HEC: 140

As you can see I'm on interleaved as I have FEC errors and have a full 8128 sync.


U aren't on interleaved because if u are, it would be sync rate at 7616k!

plusnetADSL2+15.7 Meg
Administrator MrSaffron
(staff) Thu 19-Sep-13 20:12:18
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Re: Interleaving on ADSL Max


[re: 4M2] [link to this post]
 
8128 / 53 ie size of the atm packet

Andrew Ferguson, [email protected]
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 jelv
(knowledge is power) Thu 19-Sep-13 21:13:15
Print Post

Re: Interleaving on ADSL Max


[re: adslmax] [link to this post]
 
1. If I was on Fastpath there would be no FEC errors - you can only get them when interleaving is on.

2. The router reports:

xdsl info expand=enabled
Physical Layer Statistics:

Modem state: up
Up time (Days hh:mm:ss): 2 days, 8:37:33
xDSL Standard: ITU-T G.992.1
xDSL Annex: Annex A
Channel Mode: Interleaved

3. As part of the diagnosis of a recent problem Plusnet asked for interleaving to be turned on, I saw a jump in the latency.

PS It would help if you learned how to post to this forum properly - you posted as a reply to a post by 4M2, not as a reply to my post.

jelv

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

Edited by jelv (Thu 19-Sep-13 21:17:37)

Standard User RobertoS
(sensei) Thu 19-Sep-13 21:32:14
Print Post

Re: Interleaving on ADSL Max


[re: adslmax] [link to this post]
 
In reply to a post by adslmax:
U aren't on interleaved because if u are, it would be sync rate at 7616k!
Wrong. IIRC, already discussed. If router and DSLAM are both Broadcom based, it just needs the right firmwares and settings.

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 51.8/16.8Mbps @ 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.
Standard User adslmax
(knowledge is power) Thu 19-Sep-13 21:41:55
Print Post

Re: Interleaving on ADSL Max


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
In reply to a post by adslmax:
U aren't on interleaved because if u are, it would be sync rate at 7616k!
Wrong. IIRC, already discussed. If router and DSLAM are both Broadcom based, it just needs the right firmwares and settings.


ah ok then.

plusnetADSL2+16 Meg
Standard User RobertoS
(sensei) Thu 19-Sep-13 21:50:34
Print Post

Re: Interleaving on ADSL Max


[re: adslmax] [link to this post]
 
Some of the old Tiscali AR7 kit handled it as well I think. As long as the exchange had Broadcom.

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 51.8/16.8Mbps @ 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.
Standard User adslmax
(knowledge is power) Thu 19-Sep-13 21:53:23
Print Post

Re: Interleaving on ADSL Max


[re: RobertoS] [link to this post]
 
I think my Netgear DGND3700v2 had broadcom chip on it?

plusnetADSL2+16 Meg
Standard User RobertoS
(sensei) Thu 19-Sep-13 22:02:34
Print Post

Re: Interleaving on ADSL Max


[re: adslmax] [link to this post]
 
No idea sorry.

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 51.8/16.8Mbps @ 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.
Standard User yarwell
(sensei) Fri 20-Sep-13 12:09:31
Print Post

Re: Interleaving on ADSL Max


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
Don't forget with there is a setting that allows the full 8128 on interleaved
Indeed, I used to get it.

Doesn't explain why it drops to 7616 without the S=1/2 option or whatever it's called. Perhaps I'll read it up.

--

Phil

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

MaxDSL diagnostics
Standard User yarwell
(sensei) Fri 20-Sep-13 14:47:11
Print Post

Re: Interleaving on ADSL Max


[re: 4M2] [link to this post]
 
In reply to a post by 4M2:
Perhaps the IP Profiling system on G.DMT will only work on speeds up to 8128Kbps and there wouldn't be any advantage in having a faster downstream sync speed?

8128 is listed at https://www.iol.unh.edu/services/testing/dsl/knowled... as a speed ceiling in some circumstances -

Due to limitations in system
architecture, specifically the maximum allowable Reed-Solomon codeword size (255 bytes), the maximum
achievable downstream data rate is 8.16Mbps. However, in real world systems at least one byte of each ReedSolomon codeword will be used for framing overhead, thus limiting the maximum achievable downstream data rate
to 8.128Mbps.


if the Alcatel and other DSLAMs adopted that approach in the early days you can see how it became psrt of the product spec.

--

Phil

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

MaxDSL diagnostics
Standard User RobertoS
(sensei) Fri 20-Sep-13 18:55:11
Print Post

Re: Interleaving on ADSL Max


[re: yarwell] [link to this post]
 
That's a great find Phil. Thanks smile.

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 51.8/16.8Mbps @ 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.
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