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Standard User maxima120
(newbie) Sat 01-Feb-14 15:48:10
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Compare ADSL modems/routers by latency


[link to this post]
 
Is there a recent article which compares ADSL modems (modem/router) devices by their internal latency?

I cant find anything.. Google becoming more and more useless with all those 'individualisation' feature kicked in..

I need to find a low latency modem (or modem/router) with good brand and withing reasonable amount of money.

But I need to find the latency figures somehow..

Any ideas?
Administrator MrSaffron
(staff) Sun 02-Feb-14 09:49:20
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Re: Compare ADSL modems/routers by latency


[re: maxima120] [link to this post]
 
Never seen anyone test it.

You talking adsl, vdsl, cable or fttp routers?

For most services the wan connection itself is vastly more variable latency wise

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 maxima120
(newbie) Sun 02-Feb-14 10:39:48
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Re: Compare ADSL modems/routers by latency


[re: MrSaffron] [link to this post]
 
Adsl, Andrew smile) the hint is in the title..

To be more specific i am interested in 2 kinds of latency.

One is what i called internal - latency between adsl line and the ethernet port. The one which is solely a characteristic of the modem/router.

The other is between the modem adsl port and the isp modem adsl port (which may or may not have relation to my modem - i am not sure whether a better modem can make it slightly less delayed).

So i am looking for the benchmarks on the 'internal' latency..

Presumably some cisco products must lead the band. But i want to find a price/ratio product..

Yes i know what 99% would think. What the heck he is talking about. How difference in 50 microsec would make a difference if you are looking at 100 millisec latency to a meaningful internet service..

May be not. But i'd like to know! smile


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Standard User jchamier
(eat-sleep-adslguide) Sun 02-Feb-14 11:12:46
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Re: Compare ADSL modems/routers by latency


[re: maxima120] [link to this post]
 
In reply to a post by maxima120:
Presumably some cisco products must lead the band.

Maybe, maybe not.

Home user ADSL in the UK is dominated by PPPoA encapsulation (and PPPoE on FTTC/VDSL). However some ISPs don't use this (notably Sky, but they seem to be moving back to PPPoA). One question to ask router manufacturers is if they have hardware acceleration of the PPP as that will also affect latency of the packets passing from Ethernet to ADSL.

I think there was a page somewhere on fastest routers with WAN to LAN throughput; and there was a thread in the FTTC forum last year about the unexpected overhead that PPPoE causes for those with fast lines (330 Mbps on FTTP).

James BT Infinity 2 19/09/2012 - Sold 42/6 - Getting 49/8.5 - Sync 53 / 9.5 Mbps @ 470m approx
14 years of broadband (ntl: cable to BT FTTC) - Router: Asus RT-N66U - Modem: Huawei HG612 speedtest
Standard User maxima120
(newbie) Sun 02-Feb-14 11:30:30
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Re: Compare ADSL modems/routers by latency


[re: jchamier] [link to this post]
 
Thank you. You gave me the right directions.. Will dig in..

However wanted just to point out that throughput isnt related to latency. Not directly. But presumably higher quality modem with higher throughput might have lower latency
Standard User RobertoS
(sensei) Sun 02-Feb-14 11:44:48
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Re: Compare ADSL modems/routers by latency


[re: maxima120] [link to this post]
 
However, I suggest that what you are talking about is not compatible with "... good brand and withing reasonable amount of money", unless your definition of "reasonable" is fairly high wrt modems and modem/routers. How far above £100 do you mean?

My broadband basic info/help site - www.robertos.me.uk | Domains,site and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 59.4/14.4Mbps @ 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 02-Feb-14 11:45:14)

Standard User jchamier
(eat-sleep-adslguide) Sun 02-Feb-14 13:16:52
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Re: Compare ADSL modems/routers by latency


[re: maxima120] [link to this post]
 
In reply to a post by maxima120:
However wanted just to point out that throughput isnt related to latency. Not directly. But presumably higher quality modem with higher throughput might have lower latency

Yes, agreed. It was the only data point I knew of. However even if you find a router (cisco, juniper, etc) that can route from one side to the other in 1ms (quite possible in enterprise environments with 1 GigE) the added complexity of having to encapsulate the packet in a PPP frame adds a bunch of unknown CPU time and the router software efficiency.

James BT Infinity 2 19/09/2012 - Sold 42/6 - Getting 49/8.5 - Sync 53 / 9.5 Mbps @ 470m approx
14 years of broadband (ntl: cable to BT FTTC) - Router: Asus RT-N66U - Modem: Huawei HG612 speedtest
Standard User maxima120
(newbie) Sun 02-Feb-14 13:27:06
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Re: Compare ADSL modems/routers by latency


[re: RobertoS] [link to this post]
 
its tricky question, my employer will pay for it... but if the price raises the eyebrows they wont smile so am not sure.. 200-250? I guess..
Standard User RobertoS
(sensei) Sun 02-Feb-14 13:32:42
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Re: Compare ADSL modems/routers by latency


[re: maxima120] [link to this post]
 
Unless they are in huge money trading they'd be better looking after their business than worrying about it.

Even if they are, they would be better getting their auto-trading software re-written in C rather than any C++ or similar higher level language. That's if they can find anyone still able to write a working complex system in it these days.

My broadband basic info/help site - www.robertos.me.uk | Domains,site and mail hosting - Tsohost.
Connection - Plusnet UnLim Fibre (FTTC). Sync ~ 59.4/14.4Mbps @ 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 maxima120
(newbie) Sun 02-Feb-14 13:52:23
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Re: Compare ADSL modems/routers by latency


[re: RobertoS] [link to this post]
 
I know the theme.. But its nothing to do with it..

in this case its just my own preference to get a decent modem.. Obviously nobody can make money on latency trading sitting in the middle of nowhere
Standard User maxima120
(newbie) Sun 02-Feb-14 14:26:21
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Re: Compare ADSL modems/routers by latency


[re: maxima120] [link to this post]
 
I haven't looked at modems for about 2 yrs.. Lots of changes..

Kinda like this one: http://www.asus.com/uk/Networking/DSLN66U/

Can I reuse it if (ever!?) BT Infinity will be served on my cabinet?
Administrator MrSaffron
(staff) Sun 02-Feb-14 16:05:28
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Re: Compare ADSL modems/routers by latency


[re: maxima120] [link to this post]
 
I think the problem is that to do this testing in a meaningful way you need to spend a good few thousands of pounds on a test setup where has many parameters as possible are under control, i.e. own and configure the DSLAM too and a suitable cable loading to simulate different distances.

All that would be thrown away by any ISP that runs a DLM system that might impose a greater depth of interleaving.

To be frank, anyone looking at shaving 1 to 2 ms from an ADSL line is using the wrong technology, then need to be looking at full fibre connectivity and save all the time the ADSL maths takes and rely on fibre interfaces which are much faster.

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.
Administrator MrSaffron
(staff) Sun 02-Feb-14 16:06:25
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Re: Compare ADSL modems/routers by latency


[re: maxima120] [link to this post]
 
Which based reports from actual users the built in VDSL2 modem is slow in terms of throughput. So yes that modem would work on a FTTC service.

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 maxima120
(newbie) Sun 02-Feb-14 16:59:49
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Re: Compare ADSL modems/routers by latency


[re: MrSaffron] [link to this post]
 
Totally agree.. Now tell that to the conservation officer who stopped bt from pulling fibre to my home smile
Administrator MrSaffron
(staff) Sun 02-Feb-14 19:51:51
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Re: Compare ADSL modems/routers by latency


[re: maxima120] [link to this post]
 
Based on other thread you mean fttc whereas i was talking fttp

Fttc can have higher latency than adsl2+ depending on depth of interleave used

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.
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