My SIP Trunk provider (CenturyLink) has given me a list of all of our DIDs and their corresponding registered physical addresses. I have the ability to update that in their portal as needed, so that side of things is figured out.
What I need to figure out is how to make sure when user1 dials out from their Zulu (or other softphone) client at their desk (or their desk phone or whatever the case may be) the outbound CID number it comes from is correct.
Some thoughts I had:
Choose the CID based on the IP address of the SIP peer. (seems complicated)
Manually set each location’s extensions to use the appropriate CID and let remote workers know they should not use their softphone for 911.
Setup a dedicated emergency Outbound route for each location with the appropriate CID and only allow that location’s extensions to use their emergency Outbound route.
The part that has me stumped is how to handle remote workers and workers who change offices regularly (sometimes within the same day). I want to keep management of this as low as possible to prevent human error.
Under each extension in the Advanced tab there is a field called Emergency CallerID. You can put the associated DID to be used for 911 there. Then you create an Outbound Route for 911, choose “Emergency Route” and do not add a Route CID and make sure “Override Extension” is disabled.
When someone calls 911 this route will match and because it’s tagged as an Emergency Route the outbound callerid macro will look for the extensions Emergency CallerID and use that.
I would suggest any extensions that are or can be mobile, hard or soft, be redirected QUICKLY to a BRIEF but succinct message that the call must be made from the users cell phone, all the warm-ware units using such mobile extensions will have been previously well drilled of the need to NOT USE the softphone or hardphone for 911 calls.
A) Cell phone service will use GPS to locate the call for the E911 service they get connected to,
B) Every user of these mobile extension will either have a phone in their pocket or just use the ‘other button’ for such calls, most Android softphones allow direct integration with phone dialing , some allow controlling the ‘trunk’ used by dial pattern
