Re: Out-of-band paging

[Joel M Snyder <Joel.Snyder () Opus1 COM>]

On 7/28/10 3:40 PM, Joe Greco wrote:

> I would definitely consider the direction that cell and SMS is moving to
> be at-risk and probably effectively in-band during a communications
> crisis.  As I pointed out to someone else last night in private e-mail:
> [summary: TDM will run over same infrastructure too]

I agree with you & Brandon in terms of the directions: yes, your local 
access (and your tower access for GSM) will likely all be backhauled 
over the same unexpectedly attenuated piece of fiber, causing your 
alerts to be as silent as your dial tone.

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.

Obviously, using SMTP-to-SMS-over-the-Internet to tell yourself that 
your SMTP infrastructure is hosed is the wrong answer.

On the other hand, triply-redundantly engineering things to deal with 
the outage of the fiber that connects your building, POTS, GSM, and 
everything else may not be the right answer.  To some extent, there's 
the practical question of "if my entire city is disconnected, do I 
really need to know about it since I probably can't do anything about 
it?"  (Yes, I know your help desk would want to know, but 
realistically...)

I guess my point is: yeah, Brandon, Joe, you're right.  But, I've built 
the alerting solution that minimizes the risk I will miss an alert I 
care about while also minimizing my overall cost and minimizing the 
complexity of the alerting system.  I'm happy to make it better, 
cheaper, more robust, etc., but I think it's important to balance these 
things.  (I should also note, if anyone had any doubts, that I'm also 
one of those mom-and-pop ISPs, not Time-Warner or Verizon, so my concept 
of alerting is a bit different from someone who is trying to keep tabs 
on 1300 POPs in 40 countries...)

jms


--
Joel M Snyder, 1404 East Lind Road, Tucson, AZ, 85719
Senior Partner, Opus One       Phone: +1 520 324 0494
jms () Opus1 COM                http://www.opus1.com/jms