Experiences with 911 calls and SIP
Hi all, I'm having a discussion with one of my vendors about the 911 capabilities of their SIP VoIP phone system. The vendor says that if we use an Enhanced 911 service that their phone system will transmit location information to the PSAP at the time of the call in addition to the ANI. I was under the impression that this functionality was not possible, hence all the problems that Vonage is having. Can anyone help clarify this for me? Thanks, Dan
On Wed, 18 May 2005, Dan Lockwood wrote:
I'm having a discussion with one of my vendors about the 911 capabilities of their SIP VoIP phone system. The vendor says that if we use an Enhanced 911 service that their phone system will transmit location information to the PSAP at the time of the call in addition to the ANI. I was under the impression that this functionality was not possible, hence all the problems that Vonage is having. Can anyone help clarify this for me? Are you buying just the hardware or the service as well?
If you are buying some voice-related service, there's absolutely no reason why they *can't* be transmitting ALI/PS (that's location identification) along with the ANI when 911 call is placed. The reason Vonage didn't do it is because they a) didn't want to do it b) didn't have to do it. Both have now changed and Vonage is busily working on e911 integration. -alex
On Wed, 18 May 2005, Dan Lockwood wrote:
I'm having a discussion with one of my vendors about the 911 capabilities of their SIP VoIP phone system. The vendor says that if we use an Enhanced 911 service that their phone system will transmit location information to the PSAP at the time of the call in addition to the ANI. I was under the impression that this functionality was not possible, hence all the problems that Vonage is having. Can anyone help clarify this for me?
The vendor *CAN*, if they are properly connected to the selective routers and ANI/ALI database, both route the call to the correct PSAP and display the location of where you *TELL* them the phone is located. He isn't technically correct that the system transmits location information to the PSAP at the time of the call. The system transmits ANI (calling number) and the PSAP queries a regional database to obtain the location. It can take several hour sor even days to update the database if you move. In most cases, telephone service providers *MUST* maintain a toll-free number available to the PSAP operators 24/7. In the event of missing or incorrect location information, the PSAP can call the carrier who *MUST* answer with a human being[1], not an auto-attendant. That person can then tell the PSAP the current location of record. If you take your Xten laptop to Bangladesh and register your SIP phone there, don't expect the ambulance to arrive where you *ARE*, only where you told your carrier the phone was located. The same issue occurs with off-premise stations to analog PBX systems and the like. G.I.G.O. [1] I suppose that the human being could be in India and give the same level of service we've all grown to cherish from SBC and AT&T... -- Jay Hennigan - CCIE #7880 - Network Administration - jay@west.net WestNet: Connecting you to the planet. 805 884-6323 WB6RDV NetLojix Communications, Inc. - http://www.netlojix.com/
On Wed, 18 May 2005, Dan Lockwood wrote:
I'm having a discussion with one of my vendors about the 911 capabilities of their SIP VoIP phone system. The vendor says that if we use an Enhanced 911 service that their phone system will transmit location information to the PSAP at the time of the call in addition to the ANI. I was under the impression that this functionality was not possible, hence all the problems that Vonage is having. Can anyone help clarify this for me?
Given the state of flux that VoIP is in right now regarding E911, your best bet may be to set up the PBX at each site to route 911 to a bank of two or three outgoing POTS lines. (I will be very interested to find out what you eventually decide. In addition to the work I'm doing at JustThe.net, I'm working at another California school district, and our assistant IT director is talking about possibly going VOIP in the next few years.) -- JustThe.net - Apple Valley, CA - http://JustThe.net/ - 888.480.4NET (4638) Steven J. Sobol, Geek In Charge / sjsobol@JustThe.net / PGP: 0xE3AE35ED "The wisdom of a fool won't set you free" --New Order, "Bizarre Love Triangle"
I can't see any reason it wouldn't be possible with appropriate cooperation from the Telco and Government agencies involved. However, the real question is how do they know the location and which PSAP to route you to. Your SIP phone could be anywhere in the world, literally, without changing anything about it's SIP registration other than the IP address (and, with VPNs, maybe not even that). Owen --On Wednesday, May 18, 2005 9:44 AM -0700 Dan Lockwood <dlockwood@shastacoe.org> wrote:
Hi all,
I'm having a discussion with one of my vendors about the 911 capabilities of their SIP VoIP phone system. The vendor says that if we use an Enhanced 911 service that their phone system will transmit location information to the PSAP at the time of the call in addition to the ANI. I was under the impression that this functionality was not possible, hence all the problems that Vonage is having. Can anyone help clarify this for me?
Thanks, Dan
-- If it wasn't crypto-signed, it probably didn't come from me.
participants (5)
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alex＠pilosoft.com -
Dan Lockwood -
Jay Hennigan -
Owen DeLong -
Steven J. Sobol