[LINK] Fwd: Look, up in the sky! [Was: Lag will set our broadband back: expert]

Crispin Harris crispin.harris at gmail.com
Wed Jul 29 13:44:08 AEST 2009

 On Wed, Jul 29, 2009 at 10:51 AM, Jan Whitaker <jwhit at melbpc.org.au> wrote:

> At 12:01 PM 29/07/2009, David Boxall wrote:
> >So what are the potential impacts on reliability, durability,
> >maintenance costs and value of the network, given that it seems much -
> >if not most - of it will be overhead?
> Part of it will depend on what support systems they put in place. If
> they don't have a maintenance strategy, the reliability will suffer.
> I don't know how resilient fibre is, though. It is glass, but may be
> quite flexible in the strands in cables. At least they won't be
> subject to backhoes. ;-)
> Jan

Fibre can be quite resilient to the vagaries of wind/weather and percussive
vibration that open-air cables receive - IF the right type of cable is

A cable with a reinforced wire-mesh shield, external tensioning and
strain-relief can be VERY resistant to environmental affects (up to a

However, taking the view of someone who is a cynical security
analyst/consultant and have been an IT/ICT responder to disasters in
multiple locales, there ARE some risks that are not generally considered (or
are rejected).

In *SOME* cases, pole-top can have substantial (read: business destroying)
the representative example in this case is Hurricane Katrina in Louisiana
(sic) some years ago.

The majority of the fibre in the gulf states of the US was pole-top fibre
laid by cheaper alternative telcos, with Bell-South having the vast majority
of the subterranean conduit.

With the passing of the hurricane, massive amounts of the pole-top network
was found (days/weeks later) up to several hundred kilometres away from it's
operational location.

Unlike the power infrastructure, very little of the pole-top fibre survived
the winds, and even when the cables did, local segment replacement is
usually infeasible. (thus complicating the options for return-to-service).

The long-and-the short of this is that those communications networks that
were reliant on pole-top infrastructure in the hurricane zone were severely
impacted (in a number of cases the service providers did not recover from
the event, and quietly folded into Bell-South and other major

NOTE: This is a specific risk case, and only a valid concern in
Hurricane/Cyclone prone areas. (But given that Cyclone weather systems have
passed as south as Perth greater metropolitan area in recent memory (read:
late 80's) ... )

(It would be REALLY interesting to see the comparative
deployment/maintenance/support costings for Pole-top vs subterranean cable
over several time-frames: Installation; 5 years; 10 years & 25 years. Mostly
because some of the maintenance savings that you see in pole-top electricity
distribution do not occur in Optical fibre environments.)

Crispin Harris
crispin.harris at gmail.com
"Well, you know... most Catholics are so boring, you kind of expect them to
be fairly reasonable and not, say, frothing papal fanboys with the IQ of a
turnip. So he had me fooled. Not any more, though."
Thanks to Eric The FruitBat (etfb.livejournal.com)

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