nanog mailing list archives
Re: Vonage Selects TCS For VoIP E911 Service
From: Brad Knowles <brad () stop mail-abuse org>
Date: Wed, 20 Jul 2005 12:46:03 +0200
At 11:21 AM +0100 2005-07-20, Michael.Dillon () btradianz com wrote:
On the other hand, maybe all you want to do is to route the call to the right E911 center. In that case, as long as you are in the right county you are probably OK.
If all you use the "last known position" information for is routing to the correct E911 system, that might be okay. However, one thing I believe you need to also transmit along with the position information is "time since last fix", so that you can get some sort of idea how long it's been since that position information was reasonably accurate.
If the time since last fix is several hours, then the person might now be on a plane using a picocell or broadband wireless network connection that is not position-enhanced, and using the position information for routing to the presumed correct E911 system may be inappropriate.
So long as we give additional information which gives the system an idea of the expected level of age and error in the information, I think the risks should be able to be reasonably minimized.
In any case, no solution to E911 and VoIP is likely to meet 100% of its requirements, but if you can improve the situation significantly, then it is still worth doing.
I guess it also depends on what you mean by "significantly". Is a 10% solution significant? Do you need 90% before you're significant? And what's the cost of false positives, as well as false negatives? I think all these factors need to be considered, when looking at potential solutions.
-- 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.
Current thread:
- Re: You're all over thinking this, (continued)
- Re: You're all over thinking this Crist Clark (Jul 22)
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- Re: You're all over thinking this Crist Clark (Jul 22)
- Re: You're all over thinking this Peter Corlett (Jul 21)
- Re: You're all over thinking this John Dupuy (Jul 22)
- Re: Vonage Selects TCS For VoIP E911 Service Michael . Dillon (Jul 20)
- Re: Vonage Selects TCS For VoIP E911 Service Andre Oppermann (Jul 20)
- Re: Vonage Selects TCS For VoIP E911 Service Brad Knowles (Jul 20)
- Re: Vonage Selects TCS For VoIP E911 Service Pete Templin (Jul 20)
- Re: Vonage Selects TCS For VoIP E911 Service Jeffrey I. Schiller (Jul 20)
- Re: Vonage Selects TCS For VoIP E911 Service Michael . Dillon (Jul 20)
- Re: Vonage Selects TCS For VoIP E911 Service David Barak (Jul 20)
- Re: Vonage Selects TCS For VoIP E911 Service Ryuichi TAKASHIMA (Jul 20)
- Re: Vonage Selects TCS For VoIP E911 Service Michael . Dillon (Jul 20)
- Re: Vonage Selects TCS For VoIP E911 Service Alex Rubenstein (Jul 20)
- Re: Vonage Selects TCS For VoIP E911 Service Joel Jaeggli (Jul 20)
- Re: Vonage Selects TCS For VoIP E911 Service Stephen Sprunk (Jul 20)