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Standard User tommy45
(knowledge is power) Thu 04-Oct-12 20:04:38
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Re: Interleaving on FTTC lines


[re: Ixel] [link to this post]
 
In reply to a post by Ixel:
Interleaving on VDSL2 is no where near as bad as it was on ADSLx (1, 2, 2+). Unless interleaving is quite high (e.g. INP 5 or greater) pings are still quite low in my view. I'm currently on INP 3, delay 8, depth hovering around 1000, and I am getting 16ms-18ms to bbc.co.uk.
Thing worrying thing is that DLM is able and capable of basically borking things on that front, as well as stealing sync too,
The end user who is paying should be given the choice of having a connection free from DLM and having fast path if they so desire it , Apart from one or two of the mass market Isp's insisting on it, I see no reason why those smaller ISP's could not do this once openreach recovered from their senior moment or three ,

Standard User jchamier
(knowledge is power) Thu 04-Oct-12 20:36:16
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Re: Interleaving on FTTC lines


[re: tommy45] [link to this post]
 
In reply to a post by tommy45:
Thing worrying thing is that DLM is able and capable of basically borking things on that front, as well as stealing sync too, The end user who is paying should be given the choice of having a connection free from DLM and having fast path if they so desire it , Apart from one or two of the mass market Isp's insisting on it, I see no reason why those smaller ISP's could not do this once openreach recovered from their senior moment or three ,


You're assuming DLM is there to break things. In fact its there because 99% of end users actually want a working internet connection - rather than one that is unusable for most of the day.

James BT Infinity 2 19/09/2012 - Estimate 44.6/6.5 - Install 52/12 - Actual 46 / 8 Mbps
13 years of broadband - ntl:(512k/1M)/BTbusiness(2M)/Metronet(2M)/Bulldog(8M/16M)/BE(16M)/BT FTTC(50M)
Standard User Ixel
(member) Thu 04-Oct-12 21:16:02
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Re: Interleaving on FTTC lines


[re: jchamier] [link to this post]
 
Still, if you accept responsibility you should have the option of being able to override DLM, e.g. a fixed profile. For example, I would rather have 12dB SNRM target on downstream and no interleaving, as opposed to INP 3, depth 1000~ and delay 8.

The best I've come to modifying the target SNRM (by offset or by specifying a maximum sync rate on DS and US) is using the Fritz!Box 7390, it has options which appear to do what they state, even though the HG612 isn't able to (I don't think the HG612 --snr parameter was designed for VDSLx anyway, only ADSLx). In my brief testing the only thing I will say is that this does temporarily alter your minimum and maximum sync rate set by the DLM. I didn't really spend long enough with testing this though as I found the HG612 still syncs far better (more speed) and is far more stable compared to the FB 7390 modem chip.


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Standard User RobertoS
(sensei) Thu 04-Oct-12 22:15:45
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Re: Interleaving on FTTC lines


[re: Ixel] [link to this post]
 
Yes re how the Fritz box does it. Uses a command it has to limit the rate, which indirectly alters the noise margin. In the same was as ADSL Max would normally give high noise margins once an 8128kbps sync was achieved.

I searched around for any way to rate limit on the HG612 but failed miserably.

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet Extra Fibre (FTTC). Sync ~ 56.0/13.9Mbps @ 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 asbokid
(member) Thu 04-Oct-12 22:21:44
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Re: Interleaving on FTTC lines


[re: Ixel] [link to this post]
 
In reply to a post by Ixel:
The best I've come to modifying the target SNRM (by offset or by specifying a maximum sync rate on DS and US) is using the Fritz!Box 7390, it has options which appear to do what they state

Any chance of some proof of this, please?!
even though the HG612 isn't able to (I don't think the HG612 --snr parameter was designed for VDSLx anyway, only ADSLx).

By all accounts (except yours), the DLM algorithm in the MSAN firmware sets the target SNR margin. This cannot be over-ridden by the VDSL2 CPE. Not by the Lantiq, not by the Ikanos, not by the Broadcom.. none of them can over-ride the DLM wink
I didn't really spend long enough with testing this though as I found the HG612 still syncs far better (more speed) and is far more stable compared to the FB 7390 modem chip.

What happened with the Cisco 887VA VDSL2 modem-router you were heralding a few months ago?

Back in June you were claiming that it was notably superior in performance to the Huawei (in spite of sharing the same chipset). This was your claim:
In the speed test the Cisco 887VA gets around 1Mbps better speed [than the HG612] on both download and upload.

The depressing thing is that some people might follow your advice. Only to squander £200, £300, maybe even £500 on a replacement VDSL2 modem.
And almost certainly it won't function any better than the modem supplied free by BT!

Cui bono? wink

cheers, a

Edited by asbokid (Thu 04-Oct-12 22:22:49)

Standard User RobertoS
(sensei) Thu 04-Oct-12 22:32:36
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Re: Interleaving on FTTC lines


[re: asbokid] [link to this post]
 
I went through an earlier post of his with fairly good proof. That's where I picked up on the Rate Limiting command, which is what he uses. See my previous post.

I'm sure he is right. As are you when you say trying to set the sync-time SNRM on the HG612 doesn't work. In fact in my experiments it really messes (in a small way) your syncs.

The rate limiting parameter is absent in xdslcmd frown. Which probaly means it isn't available on the chipset. But you're the guy who will find it if it does exist!

Deprecated in the current OR SIN of course - newly introduced as it wasn't there before they added the self-install modem or modem/router specs.

My broadband basic info/help site - www.robertos.me.uk | Domains,website and mail hosting - Tsohost.
Connection - Plusnet Extra Fibre (FTTC). Sync ~ 56.0/13.9Mbps @ 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 tommy45
(knowledge is power) Thu 04-Oct-12 22:36:08
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Re: Interleaving on FTTC lines


[re: jchamier] [link to this post]
 
In reply to a post by jchamier:
In reply to a post by tommy45:
Thing worrying thing is that DLM is able and capable of basically borking things on that front, as well as stealing sync too, The end user who is paying should be given the choice of having a connection free from DLM and having fast path if they so desire it , Apart from one or two of the mass market Isp's insisting on it, I see no reason why those smaller ISP's could not do this once openreach recovered from their senior moment or three ,


You're assuming DLM is there to break things. In fact its there because 99% of end users actually want a working internet connection - rather than one that is unusable for most of the day.
Well for me it would break things, as the latency would increase, by an unknown quantity , But as said the customers should be given the choice as we all use our Internet connections in different ways , As for not being able to use the connection most of the day, that is no longer the case and hasn't been for ages, The broadcom chipset seems able to handle the interference better than the other conexant netgear router did if that was the reason, but i'm on a 3db profile and fastpath , oh and when interleave and INP was applied that made little difference So it IMO borks the connection

Standard User Ixel
(member) Thu 04-Oct-12 22:41:10
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Re: Interleaving on FTTC lines


[re: asbokid] [link to this post]
 
I did post some proof on the kitz forum. But I didn't continue testing for reasons as stated, but I can't say I was encouraged to continue testing given your replies either.

If people wish to try this, that's their perogative, but I found from the small testing period that it didn't influence DLM to increase my profile (reduce interleaving) any quicker, or at all. Perhaps if I had given it more time it may have.

Can you explain why my IP profile was lower, my speed was lower, and my min rates accordingly adjusted, when I was performing a sync rate cap on my FB7390 during the testing? Matching what I virtually set the rates to. I know you're still going to doubt me whatever I post, even if I went back to testing to try and give you more and more proof, so I won't waste my time.

As for my Cisco 887VA, I sold it. I don't have to justify my reasons why. Perhaps it's best that I avoid any further participation on forums with any information I find and share, in future.

Thanks for your reply.

Edited by Ixel (Thu 04-Oct-12 22:48:50)

Standard User jchamier
(knowledge is power) Thu 04-Oct-12 23:14:29
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Re: Interleaving on FTTC lines


[re: tommy45] [link to this post]
 
In reply to a post by tommy45:
Well for me it would break things, as the latency would increase, by an unknown quantity ,


On ADSL the latency increase could be 5ms or even more with interleaving. I've read here that on VDSL the difference is 1ms or less.

Really can anyone tell the difference in 1ms latency? Especially if a specific server you connect to has a CPU load issue (due to faulty code) is more likely to be late in replying by upto 1 or 2 seconds?

James BT Infinity 2 19/09/2012 - Estimate 44.6/6.5 - Install 52/12 - Actual 46 / 8 Mbps
13 years of broadband - ntl:(512k/1M)/BTbusiness(2M)/Metronet(2M)/Bulldog(8M/16M)/BE(16M)/BT FTTC(50M)
Standard User tommy45
(knowledge is power) Fri 05-Oct-12 00:05:35
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Re: Interleaving on FTTC lines


[re: jchamier] [link to this post]
 
But that was the personal experience of one FTTC customer & in all fairness only is representative of that lines characteristics ,

As for the remainder it will be a "Post code lottery "so to speak,So they could well see a very different picture

And "base latency" ,s also Dependant on where in the country you happen to live or work, and of course the ISP's Peering as well as it's backhaul transits will play a significant part also in cases where BTwholsale wbc backhaul/peering isn't used

But the point remains the bill paying customer should be given the choice of what they want ,is that really asking too much, considering that VDSL is supposed to be the future?

Edited by tommy45 (Fri 05-Oct-12 00:08:12)

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