911 Configuration

[PNI-ITRNP]

I am a consultant who has adopted a configuration of Cisco Telephony that was previously configured by another firm. That firm did not provide much in the way of documentation. In any case, this organization has added three new satellite offices in the last 6 months prior to us coming onboard, all in the same area code. The sites are connected either via a MetroE connection or a site-to-site VPN.

The organization recently realized they never configured 911 for these additional sites, and because no documentation was provided be the previous consulting firm they have tasked us with providing a solution. My forte is not in Cisco Telephony, networking, firewalls, sure no problem!

I have checked the configuration and determined that two of the sites are in the same city, the 3^rd satellite office is in a neighboring town, but in the same Area Code.

For two of the sites, I was planning on creating the Route Patterns for those sites, and the ERL and ALI information in CER. I believe they can go out the main PRI since they are in the same City.

However, the third site while it’s in the same Area code is in a different county. That site connects back to the home office via a site-to-site VPN.

The question I have is, can the 911 calls for this site go to the main PRI as the number is in the same Area Code? If it can then I should be able to configure a route pattern, create the ERL and ALI information in CER and treat it like any other satellite office. Also, I was planning on using IP Subnets in CER for the ELI Membership. Any gotchas that I should consider in any of this configuration?

Thank you in advance for any assistance the community can provide.

Rob

[Jaime Valencia]

I suggest you actually discuss this with your local 911 authorities, they should be able to tell you if the same ERL/ELIN can service all the offices, or if they're actually serviced by different PSAPs.

[Chris Deren]

It's not the area code that drives requirements for 911 routing, it's the PSAP location, if both locations belong to the same PSAP then you can use the same PRI for both, if they use different PSAPs then you may not. Configuring CUCM/CER is no sufficient for E911 to provide detailed "Location" field to PSAP, you also need ALI database configured with either directly with the provider if they can do it, or 3rd party such as RedSky or West. 

[PNI-ITRNP]

OK, this makes sense. I will need to find out and verify what PSAP this other location would be serviced by.

In the event, that it is a different PSAP, from my research it looks like I would need to add a local Voice Gateway with a connection to the local PSTN.

Is my thinking correct?

As far as the ALI Database is that submitted from CER or using another tool?

Again, this has been handed to me and while I know Cisco networking, the voice side of Cisco (aside from UCCX) is new to me. I did UCCX administration for 5 Years, but another administrator handled CUCM, CER, etc.

Thank you, Jaime and Chris, for the advice and thoughts.

[Andrew West]

When you have multiple sites like that you have a few ways you can get 911 calling out correctly. 

1. POTS lines coming in via FXO ports

2. Obviously PRIs

3. SIP if your spoke site (for example Verizon) has the correct address and your local numbers are going out of that spoke

The key to get ot the correct PSAP is typically the physical address where that number is originating from . It makes no difference if its SIP coming into your GWY because really your ITSP will typically control the physical address. 

[Chris Deren]

POTS lines are an option if E911 is required  and simple 911 is acceptable (need to consider state law), if E911 is required then other 2 listed options or CAMA trunks (if you can still get them, big if) would be the only options.

[PNI-ITRNP]

Thank you all for the responses. I apologize I was on vacation last week.

Makes sense that it is not the AREA code that drives the requirements. For two of the sites, it is clear that I can send the 911 calls out the primary PRI. These two sites use the same PSAP as the primary office.

The last site uses a different PSAP, I was able to verify this, different county different PSAP. The solution there looks like it will be adding a POTS line and using that with a 2901 Voice Gateway.

Again, I’m no expert in this arena, so could use a little guidance to finalize this solution. Especially if my thinking doesn’t sound doable! J My thoughts for the third site are:

1. Add 2901 Voice Gateway with FXO Pots line.
2. Route Group\List\Pattern in CUCM would direct 911 calls at this site to local gateway.
3. CER would have the correct ERL\ALI Information and I would use IP Subnet to assign that information to the correct phones at this 3rd site.

This may not be in the order of configuration but its where my brain is at. Also, the ALI Database still has me confused. However, given the fact that it was previously configured and 911 is working at the primary office I just need to determine how to get the ALI Database information to the provider.

I’m reading all kinds of manuals right now to determine I am heading in the right direction, but if anyone can provide a concise configuration template with all steps that would be awesome.

Aside from all this, I am going to accept a response as a solution just trying to get close enough in feeling confident with the 3rd site.

Thanks all for the Help.

[Chris Deren · Accepted solution]

POTS line is OK if you only have 1 ERL for that location which is tied to the address as it will not allow you to send out different ELINs. If you need E911 capability at this time with multiple ERLs/ELINs then you'll need either PRI, SIP or CAMA trunk.

[PNI-ITRNP]

Yes, there will be only one ERL for that location. It's a handful of phones at best.