I'm fairly familiar with CUCM and prinicples of IP Telephony but I'm very green with CER. I have a CER server at HQ that covers a building with 3 floors and about a dozen zones. All of the route patterns to support this have been setup in CUCM and a contiguous block of DID numbers was set aside a long time ago specifically for CER/E911. Everything works fine with E911 at HQ.
Recently a remote office came into play. The remote office has 3 or 4 users. There's only 1 physical IP Phone (for general use). Everybody there will use IP Communicator. All of the VoIP traffic is passing across a VPN tunnel. PSTN calls from this location use a SIP trunk at HQ. I have a couple of questions. First, is it reasonable to route 911 calls across the VPN tunnel to utilize voice gateway resources at HQ? Second, if we do that can a new zone be integrated into CER for this remote office such that calls originating from the remote office will go out to the PSAP via HQ and the PSAP will show address information for the remote office (assuming that all of the paperwork is done with the provider/PSAP)?
Sending 911 calls from centrelized location should only be considered if the SIP provider support e911 functionality and can route the call to local PSAP center where the phone is located. You would need to define different ERL/ELIN for those sites in CER. If that is not an option your only option would be to deploy local POTS lines for 911 calling.
Does L3 provider in US support E911 ? so that we can implement centralize CER.
- what is the terminology to tell provider, so they can route particular ELIN to local PSAP center?
- we only have 1 Cisco CER with one SIP trunk in HQ which serves 25 sites (we want all 25 sites to use CER at HQ and same SIP trunk in HQ), possible ?
- If Telco is able to provide "Location" info , then even we use HQ DID, call can still route to other cities local PSAP ?
- is the "Location" you mean here is similar to ESN?
Ah I see,thanks
I thought before ,ALI database can do it, with statement below:
"Some SIP trunk providers can provide ALI database updates and others do not and then you need to rely on 3rd party such as Intrado/West, RedSky, 911ETC, etc"