Re: You're all over thinking this (was: Re: Vonage Selects TCS For VoIP E911 Service)

[Brad Knowles <brad () stop mail-abuse org>]

At 4:19 PM -0700 2005-07-20, Steve Gibbard wrote:

>  At some point it makes sense to solve the problems you can solve, rather
>  than inventing new ones.

	True enough.  However, the tough problems are always the ones you 
never thought of before you started building the system.  Therefore, 
it helps to try to come up with as many scenarios as you can, and try 
to find the various weaknesses in the system.  You might decide to 
not try to do anything to fix them, but you should at least be aware 
of them.

	For example, one example came to me tonight -- get a CDMA mobile 
phone with EV-DO and a flat-rate subscription, then run a SIP/VOIP 
softphone over that.  Yes, the cost of the EV-DO flat rate is high, 
but a few short duration long distance calls per month could very 
easily exceed the monthly rate you'd pay.  And in times of trouble, 
people frequently grab the device they're most familiar with, and not 
necessarily the right one for the job at hand.


	In the case of regular cell phones, if you are roaming on a 
network in a foreign country, or you have rented a local phone, I 
understand that the carriers have gotten together and made sure that 
the various 911/112/999 emergency services numbers work world-wide, 
so that if you're an American in Europe, you can still call 911 and 
have that work as expected.

	But in the case of the EV-DO softphone, things get nastier.  And 
I can see companies deciding to go with a dedicated EV-DO softphone, 
to save on overall expenses.

--
Brad Knowles, <brad () stop mail-abuse org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

    -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
    Assembly to the Governor, November 11, 1755

  SAGE member since 1995.  See <http://www.sage.org/> for more info.