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