[LINK] Does the NBN bring redundancy?

Paul Brooks pbrooks-link at layer10.com.au
Wed Oct 5 11:21:21 AEDT 2011

On 5/10/2011 5:53 AM, Fernando Cassia wrote:
> As an observer from the other side of the globe, I wonder what the
> policy has been by the NBN project with regards to existing fibre
> networks. Does the NBN bring redundancy to private networks -NBN fibre
> layout in parallel with existing fibre lines- or does it re-use
> existing fibre backbones when available?.

Fernando - The fibre portion of the NBN is primarily access network - the GPON bit -
which is most parts of the country are areas where there is no existing fibre in the
access network.
Where there is access network fibre, such as within business precincts, the NBN fibre
is in parallel, so an NBN connection could be a redundancy option for a fibre-based
service on a different fibre network.
Of course, if the user wants redundancy the user would want to be mindful of whether
both fibre cables used the same ducts and building entry points.

NBN might acquire dark fibre cores from an existing fibre cable, which could be
thought of as re-using existing cables - but at the purely passive glass level, not in
any active sense.

For long-haul fibre backbones (which is what I see in my mental picture when I see the
word 'backbone') the NBN is not playing in that space - service providers have to
approach one or more of the existing long-haul fibre network operators for
transmission to get to an NBN hand-off point (Point of Interconnect), and then the
service rides on NBN fibre from there onwards.

>  If the later, does the NBN
> pay the existing fibre networks for traffic, or is there some sort of
> mutual agreement to let pass traffic free of charge in exchange for
> the use of each other´s network segments?.

The NBN does not exchange traffic with any other network within the NBN active
network. Traffic passes from an NBN-connected point through the NBN, and exits the NBN
into the RSPs network at the PoI.
Once in the RSP network of course the traffic can then be exchanged with other
networks in the usual way - including possibly re-entering the NBN at a PoI and being
carried back through the NBN to another NBN connected endpoint.

Hope this helps.


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