[VoiceOps] 911 address policy for company phones at home

Nathan Anderson nathana at fsr.com
Fri Jan 18 17:13:01 EST 2013

Kinda/sorta.  So you are doing (in essence) what I proposed in my last paragraph: transmitting a different CLID to the PSAP than you transmit to all other called parties for that station.

The thing is that this doesn't seem to solve the original poster's problem.  In your example, the station in question has a DID: 415-886-7923, and it (presumably) uses that DID for all external outbound calls, but uses the main switchboard number as the CLID when dialing emergency services (911).  That works great if all of the stations are at the same address as what is provisioned in E911 for the switchboard number.  If that station isn't at that address, I take it your solution is to "override" this so that the emergency CLID matches the external CLID, and then to provision that DID in E911 with the right address.

The way I understood it, though, the original question dealt with a scenario like this:

My internal Caller ID is: 330 (THE MARKETING GUY)
My external Caller ID is: 415.886.7900 (no DID! You call the switchboard and ask for 330.)
My emergency Caller ID is: 415.886.7900

...so the company in question -- for whatever reason, I presume they have a good one and it's not my position to ask or judge -- does not hand out DIDs to stations and wants all outbound calls to look like they are coming from HQ regardless, and station 330 is physically at MARKETING GUY's residence (since he telecommutes), not company HQ.

So, the question is, how do you transmit the correct address to the dispatcher for MARKETING GUY's residence in this scenario, instead of company HQ's address?  My proposed solution was this:

My internal Caller ID is: 330 (THE MARKETING GUY)
My external Caller ID is: 415.886.7900 (no DID! You call the switchboard and ask for 330.)
My emergency Caller ID is: 415.886.7923 ("throwaway" number)

...then you provision the dude's residential address on the 7923 number.  But MARKETING GUY has no clue that this number exists, and in fact dialing that number will not lead you to his station, thus the "throwaway" label.  (In addition to confusing MARKETING GUY when PSAP asks him if he is calling from 7923, if the call drops and PSAP tries to get hold of him again, that will fail.  Another reason why this kludgey solution is not great.)

This is all predicated on the notion that the only way that most E911 services work is by binding an address to a telephone number in a database on their end.  Are there any E911 providers that you can transmit an address to in the call signalling, in real-time during call set-up?  That would solve the problem entirely.

Nathan Anderson
First Step Internet, LLC
nathana at fsr.com

-----Original Message-----
From: Joshua Goldbard [mailto:j at 2600hz.com] 
Sent: Friday, January 18, 2013 1:47 PM
To: Nathan Anderson
Cc: voiceops at voiceops.org
Subject: Re: [VoiceOps] 911 address policy for company phones at home


CLID as it applies to the PSTN is inherently outbound. That being said, a number of switches (PBXs) have the capability of modifying the caller ID of a user. You see this with internal Caller IDs and external caller ID (extension versus CNAM). Some providers (2600hz included) have introduced a third caller ID classification: emergency.

Let me give you a practical example.

My Internal Caller ID is: 7923 (THE MARKETING GUY)
My external Caller ID is: 415.886.7923 2600hz
My emergency Caller ID is: 415.886.7900 2600hz ($Address)

The purpose here is to take our block of 100 DIDs and only support emergency services in a single uniform fashion. We can override this on a user by user or per-device basis, but the point is to simplify emergency calling.

Does that help clarify what we're doing?


P.S. I previously sent this email only to Nathan. Adding voiceops onto the chain just in case there's interest.

Joshua Goldbard
VP of Marketing, 2600hz

116 Natoma Street, Floor 2
San Francisco, CA, 94104
415.886.7923 | j at 2600hz.com

On Jan 18, 2013, at 1:04 PM, Nathan Anderson <nathana at fsr.com>

	I'm confused, and I apologize to those who have already been involved in this discussion thread for a while since I am just now jumping in.  CLID is inherently outbound, so I am not sure what you mean by "inbound vs. outbound caller IDs".  Perhaps by "inbound CLID" you mean DID, or DNIS?
	I'm also not sure how you propose to bind E911 details to a device instead of a telephone number.  The few E911 services I've looked at all only give you the option to provision E911 information via TN.  So if you propose a set-up such as what is being discussed here, where each company phone only has an internal extension # and no DID, and CLID is uniformly set to a single number for all outbound calls from any phone whether it is located in the office building or at an employee's residence, then there can only be a single E911 address for all of those phones.  That seems inescapable.  Are you saying that there are E911 companies that can provision differently, and not use the CLID as the "key" to looking up an address?  What do they use/how do they work, and can you name some names?
	The only other kludgey workaround I can think of that might pass muster would be to assign unique "throwaway" TNs to each individual extension that you would use as the CLID for outbound from that extension *only* when 911 is dialed, and continue to use the global office TN as CLID across all extensions for all other outbound calls.  It's not a perfect solution, since if the individuals using those phones have no clue about those numbers, they might get confused when asked to verify their own telephone number by the PSAP and the dispatcher reads some number back to them that isn't their main office number.  At that point, you might as well let the customer know that these numbers exist and give them the option of using them as DIDs for the extensions/devices they've been assigned to.
	Nathan Anderson
	First Step Internet, LLC
	nathana at fsr.com
	-----Original Message-----
	From: voiceops-bounces at voiceops.org [mailto:voiceops-bounces at voiceops.org] On Behalf Of Carlos Alvarez
	Sent: Friday, January 18, 2013 11:49 AM
	To: Joshua Goldbard
	Cc: voiceops at voiceops.org
	Subject: Re: [VoiceOps] 911 address policy for company phones at home
	On Fri, Jan 18, 2013 at 12:46 PM, Joshua Goldbard <j at 2600hz.com> wrote:
	Yeah, but you're talking about inbound.
	In many corporate environments, the outbound caller ID is uniform for a location (and even if it's not, most systems support uniform caller ID for emergencies). E911 is an outbound service and the inbound and outbound caller IDs can certainly be different.
	Does that help clarify my viewpoint?
	Ah, yes.  We very rarely get anyone who wants to do that, so it didn't cross my mind.
	We do have special 911 CLID/DID settings and special processing for those calls.  However we bind them to a device, since the device is what has location, in most of our installations.
	Carlos Alvarez
	VoiceOps mailing list
	VoiceOps at voiceops.org

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