[unisog] VOIP 911 considerations

Steven Leikeim sleikeim at ucalgary.ca
Mon May 26 21:10:07 GMT 2008

On Wed, May 21, 2008 at 01:35:50PM -0700, Peter Van Epp wrote:
> 	The number one fun question to ask of both your VOIP vendor and your
> risk manager is "what about 911?". Get ready to see the most amazing soft shoe
> dance from your VOIP vendor because this is very hard and ugly to get right.
> I believe our current implementation depends on poking in to switch MIBS to
> aquire the physical location of the set run the phone is currently connected
> to, I don't know if anyone has ever tried it ... An appropriate (loaded) 

If you're doing VOIP in-house, it should be possible to find an, at least
approximate, location for a phone. If you're using an outside vendor for VOIP
then you really need to make sure that the proper location information is

Here in Calgary, an incident occured with a 911 call on a VOIP phone which
resulted in a long delay in the arrival of EMS. Unfortunately, the child later
died. The 911 call was routed, not to the local emergency dispatch centre, but
to the vendor's 911 call centre. Apparently, they did not have the correct
address and called for an ambulance in the WRONG CITY!! This is apparently the
first time this problem has occured in Canada, but there are cases where this
has happened in the US.

In any case, you need to have a procedure for finding where the call originated
and how to find the phone when you arrive on-scene. It's one thing to find
someone who's in the middle of a big open space, but if they're in an odd
location they might be hard to find and/or be unable to give good information
about where they are. In any case, you need to test your ability to find a
given phone quickly before you have an emergency where that is necessary.

Steven Leikeim

News articles

National Post:	http://www.nationalpost.com/news/story,html?id=485069
The Register:	http://www.theregister.co.uk/2008/05/06/crtc_investigates_failed_911_call/
CBC:		http://www.cbc.ca/canada/calgary/story/2008/05/02/crtc-voip.html


Steven Leikeim, GSEC-Gold                 | We, the willing
Department of Electrical and Computer     | led by the unknowing
     Engineering                          | are doing the impossible
Schulich School of Engineering            | for the ungrateful.
University of Calgary                     | We have done so much
Calgary, Alberta                          | for so long with so little
                                          | we are now qualified
Phone: (403) 220-5373 Fax: (403) 282-6855 | to do anything with nothing.

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