Re: Out-of-band paging

[Martin Hepworth <maxsec () gmail com>]

On 28 July 2010 15:42, Leo Bicknell <bicknell () ufp org> wrote:

> In a message written on Wed, Jul 28, 2010 at 04:38:25PM +0200, Joel M
> Snyder wrote:
> > But... you can take this sort of 'single point of failure' argument
> > almost as far as you want.  In the security business (where I spend most
> > of my time), I see people do this a lot--they get deep into the
> > ultra-ultra-ultra marginal risk, which takes then an enormous amount of
> > money to mitigate.  It's an easy rat hole to explore, and often fun.
>
> I agree worring about the cell site is not the worry.
>
> However I suspect many of the folks relying on SMS have no idea how
> it works inside the carrier.  There are in fact other points of
> failure that may be much more "single point".  For instance your
> SMS likely passes through a database in the carrier network (in
> case your phone is off).  That's redundant, right? Fully RAID'ed
> and a hot standby spare and all that, after all it probably handles
> SMS's for a few million customers.
>
> Not always.
>
> --
>       Leo Bicknell - bicknell () ufp org - CCIE 3440
>        PGP keys at http://www.ufp.org/~bicknell/<http://www.ufp.org/%7Ebicknell/>

(view from the UK where SMS is very very prevalent)

TXT's can take ages to deliver (hours days not uncommon).

GSM networks can get put to emergency access only so they don't get swamped
when a civil emergency occurs and emergency workers  need priority access to
mobile network.  eg 7 July 2005 in London

-- 
Martin Hepworth
Oxford, UK