[AusNOG] ADSL2+ line sync data

[Mike Trewartha]

With the change in loop lengths, what is the likelihood of some bodies current decent (ie. 18mbit+) ADSL2+ sync speeds dropping once FTTN is deployed?


Regards, Mike. 

Sent from my iPhone

On 13/09/2013, at 8:32 AM, Paul Brooks <pbrooks-ausnog at layer10.com.au> wrote:

> On 13/09/2013 7:08 AM, Guy Ellis wrote:
>> Paul,
>> 
>> In response to your challenge (Exercise for the reader - work out how VDSL2 would be any different)...
>> 
>> In contrast to the current ADSL2+ network, there are 3 big differences with the proposed VDSL2 FTTN deployment - 
>> (i) shorter loop lengths (700-800m) 
>> (ii) vectoring (crosstalk--)
>> (iii) bonding (speed++)
>> 
>> While such a VDSL2 network is not as good as fibre, it's no where near as bad as the current ADSL2+ network.
>> Right now some poor folks are on 6km loop lengths, there's plenty of crosstalk and getting bonding working is a challenge.
> You can forget about pair bonding in the broader plan - I sincerely doubt the budget or street cabinets will be big enough to build two ports for every dwelling.
> 
> My point was that - without vectoring - the VDSL2 chart would look much the same.
> 
> Sure the axis labels would change - distances to 5km become distances to 800 metres, bandwidth tops out at 120 Mbps instead of 24 Mbps - but the shape of the chart would look much the same. A negligable proportion getting the full 'up to' speed, roughly 30% of people getting speeds down to 50% of the "up to" limit, and a large hump majority of people down the low end getting about 10 - 15 Mbps - probably better than the ~4 Mbps they might get now with ADSL2, but not really up to the new benchmark.
> 
> That leaves vectoring as the major difference - which will make speeds more predictable and push a lot more services to the right to higher speeds, reduce the width of the fuzzy cloud in the second diagram, but still won't deliver 50 Mbps further than about 750 metres.
> 
> 
> Anyway, back to the original topic  - I was looking for ADSL2+ data - anyone?
>  
> 
> 
>> 
>> Regards,
>>  - Guy.
>> 
>> 
>> 
>> 
>> On 12/09/2013 12:17 PM, Paul Brooks wrote:
>>> A recent Ofcom (UK) report has a very interesting chart of ADSL2+ line speeds:
>>> Ofcom Infrastructure Report 2012 Update
>>> http://stakeholders.ofcom.org.uk/market-data-research/other/telecoms-research/broadband-speeds/infrastructure-report-2012/
>>> http://stakeholders.ofcom.org.uk/binaries/research/telecoms-research/infrastructure-report/Infrastructure-report2012.pdf
>>> Figure 4 on page 11:
>>> <mime-attachment.png>
>>> This chart is effectively the result of the ADSL line-sync/attenuation curve combined with the increasing area of circles of increasing radius around the exchange - and demonstrates very clearly why so many people get low ADSL2+ line speeds.
>>> (Exercise for the reader - work out how VDSL2 would be any different)
>>> 
>>> Also scatter-plots of sync-speed with line-length, as per Figure 8 from another UK report:
>>> 
>>> <mime-attachment.png>
>>> Now every DSLAM network operator can put together similar charts - but I'm not aware of any stats for Australian networks, apart from the heat maps put out by iiNet and the adsl2exchanges.com.au site, which aren't quite what I'm looking for.
>>> For all you DSLAM operators - I would be very interested in putting together similar charts for the Australian networks, to see how our copper loop network varies from the UK network. If anyone is willing                 to share data or statistics, I'm very interested in pulling together similar Australian charts - on a non-identified, aggregated, anonymised basis if you wish.
>>> Please contact me off-list - thanks.
>>> Paul.
>>>  
>>> 
>>> 
>>> 
>>> 
>>> _______________________________________________
>>> AusNOG mailing list
>>> AusNOG at lists.ausnog.net
>>> http://lists.ausnog.net/mailman/listinfo/ausnog
>> 
>> 
>> -- 
>> Guy Ellis
>> guy at traverse.com.au
>> www.traverse.com.au
>> T: +61 3 9386 4435 M: +61 419 398 234
>> 
>> 
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