[AusNOG] DSL G.Fast Details

[Mark ZZZ Smith]

----- Original Message -----
From: Mark Delany <g2x at juliet.emu.st>
To: ausnog at lists.ausnog.net
Cc: 
Sent: Wednesday, 4 February 2015, 3:15
Subject: Re: [AusNOG] DSL G.Fast Details

On 03Feb15, Mark ZZZ Smith allegedly wrote:


> I found it particularly interesting that power is or can be supplied
> to the FTTdp node by the CPEs, which means the FTTdp equipment can
> possibly be installed inside the footpath pits themselves without
> needing power infrastructure

Is there an upgrade path to this approach or is FTTdp the end game?

* I'm not quite sure what you're asking. Are you asking about an upgrade path to FTTdp, or an upgrade path from FTTdp to FTTP?

I don't really understand how there could be an upgrade path as
replacing all the downstream copper with fibre leaves you with the
problem of powering the pit

* That's the point of my comment - the power for the 'pit'/FTTdp equipment in the pit comes from the attached subscribers' CPE (and therefore the subscribers' mains supply.) The FTTdp equipment in the pit doesn't need an independent power source. In other words, if there are no active CPE attached to the FTTdp equipment in the pit, it isn't operating.

 - unless the vestigial copper stays forever
as a power source. Alternatively, custom pit-to-premise cabling could
include POE-like stranding.

* There is no custom pit-to-premise cabling, the existing copper leadins are used - that is the specific benefit of this solution over FTTP, as FTTP requires installation of premises specific (front garden, driveway, house entry) and therefore much more expensive fibre leadins.

* For those 


Given that upstream of the pit is active, an intriguing aspect of an
optics upgrade in this scenario is that pit-to-premise could remain
active after upgrading to fibre. Intriguing because active to the
premise is what some advocate as the real end game.

* I agree it should be the end game if you going to deploy FTTP. Google got it right - symmetric active FTTP is the real end game if you're going to go to the expense of deploying fibre (as its all going to carry Internet traffic and, as described in RFC3449, the best links to carry Internet protocols over, and more specifically TCP, are symmetric ones.)

* That being said, as the main device people are now using to access the Internet are smartphones and tablets:

http://www.businessinsider.com.au/slide-deck-heres-how-internet-usage-is-changing-in-australia-2014-12


* and Chromebooks were the top 3 laptop sellers on Amazon this past Christmas:

http://www.pcworld.com/article/2863936/amazons-three-top-selling-computers-for-the-holidays-were-chromebooks.html


* I think the emerging trend could be described as 'wireless cloud first' for typical end users. I consequently wonder whether many 100s of Megabits to the home is really going to be necessary.


As an aside, at 50m gaps, how many premises per pit? 10-20 I guess?

* That'd be my guess. I might have a look over the next few days.


Mark.


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