Adding E911 Support

I’m in the middle of migrating off native asterisk to FreePBX, and have a couple of questions about E911.

In the distant past, we had problems with accidental 911 calls - our company uses 9 to get outside lines. We originally fixed the problem by changing the dial plan to require 9911.

Recently, we have been getting more geographically remote extensions. We may also deploy softphone apps on cell phones.

Q1) I’d like to use a 911 IVR to filter 911 calls using a Misc Application set to a “911” feature code. The prompt would be something like:

“You have dialed 911. If this is an emergency at the company office press *. If you are calling from a remote extension, please hang up and use your cell phone, or a local land line, to contact emergency services.”

Does this sound reasonable?

Q2) What’s the best way to transfer the call when * is pressed? I’m going to test with They need the CID set to our company number and the pbx needs to dial:

[email protected]

Can a misc destination be used to do this? Or is something like a custom extension required?


Be very careful with e911, you are legally liable if you offer it and it doesn’t work, unless you are completely confident in your VSP’s ability to assume that liability, and your own ability to do your bit right, then you shouldn’t even consider offering it.

Also, in some states, if you set up a phone (in a business) that does not have 911 on it you must put a sticker on the phone letting people no they cannot dial 911 from this handset… C.Y.A.

Too often people think of E911 remediation in their PBX as a legislative or regulatory compliance issue. The fact of the matter is that you are providing voice telephone services to a user, and in fact have taken on the responsibility of a ‘private carrier’.

Too often have I seen administrators ‘guessing’ at the law, or rationalizing their actions based on myths. Currently there is regulatory requirements in 18 states, and NENA (National Emergency Number Association) responded to an FCC Notice of Inquiry last year that “MLTS [PBX] Location capabilities are feasible, and [the FCC] should begin a proceeding to establish a timeframe for mandatory implementation.”

The rumor on the Hill is that this will be put out as a Notice of Proposed Rule-making (NPRM) in 2013, which would indicate a ruling later this year or early 2014.

In any case your concern is tort law. If an employee is harmed and your defense is “I put a sticker on the phone” think about what a jury would say to that. Martha Buyer, a respected Telecom Attorney wrote a white paper last year on E911 liability with her opinions. It is available on the 911 ETC site at:

Telecom and Legal Considerations in 911 Planning:
The Importance of a Team-Based Approach

The whitepaper examines the elements essential to constructing a reliable plan for the most efficient management of emergency information:
Technology Considerations
The Continuing Evolution of E911
Negligence and Liability 101
Federal Law and Regulation / 911-Specific Laws / State Regulations
NENA Model Legislation
911 RFPs and Implementation

Full Disclosure: Martha does not work for Avaya, although I personally recommend her in many cases. She knows Telecom, and she knows E911.

I think the whitepaper is a great start in understanding your responsibilities, and is completely vendor generic.

More information on E911 and NG911 in general are in my blogs and podcasts (links below)

Interesting discussion. I don’t think the threat of a lawsuit will keep me from implementing E911. It wouldn’t fly around my house.

My wife is an anesthesiologist. Every time she puts someone under, there is a small possibility that they won’t wake up - it’s a known percentage based on drug reaction. Not only is she faced with prospect of losing a patient every day she works, she’ll most likely get sued if someone dies. Not providing 911 service to company employees when it is so inexpensive and technically possible is morally wrong - even if it’s not a perfect solution.

Also, I visited the county emergency services office a couple of years ago to ask about 911 service. They were in difficult position as well. At the time, about 60% of all 911 calls were from cell phones, and most didn’t provide GPS co-ordinates. I would think that the current cell phone caller percentage is even higher, and hopefully most have GPS capability. Hopefully, the system has improved for the people receiving the 911 calls.

So back to my original question. I want to implement an outbound IVR for a 911 call that states the limits of the 911 call. I thought using a Misc Application with a 911 feature code would work, but found that the IVR only gets control when 911 is entered before I request dial (polycom phone). It doesn’t work if I go off-hook and then dial. I’ll get more time to investigate on Monday.


Fletch, I guess I should clarify, I would never setup a business or location without 911 capabilities, and don’t use the sticker approach, although if you look at carriers such as AT&T, they include the sticker requirement as part of their terms and conditions. I agree not only are their possible financial concerns of having been the system/service provider that didn’t provide 911 service and termination, as well as legal requirements in many states, I personally couldn’t live with the thought of someone needing emergency services and not being able to get them.

In one of the businesses I own we also do security camera work, and I often have clients ask to do audio monitoring as well, in most states legally all it takes is a sign on the front door and notice to your employees that audio recording is on the premises so you remove their expectation of privacy. However, I haven’t had a business owner talk me in to put it in yet as I am personally against it. Of course you can run to Sams Club and pick up one of their cheap CCTV systems with audio recording built into the camera. Just like the 911 stuff there are too many legal, civil and ethical issues not to just do it right the first time.

As for legislating PBX location requirements, that’s going to be tough in the future, whether it’s done by IP or some other function such as GPS embedding in the phones and towers like had to happen in the wireless industry, there are so many legacy PBXs that people are still using from decades ago, it will be a slow migration without draconian legislation requiring compliance deadlines similar to the killing of the analog wireless networks, and implementation of e911 requirements for wireless handsets. Which by the way almost killed Motorola’s cellular handset business, as they didn’t have processors that could provide the e911 integration and had to move to Qualcomm Chips for their CDMA phones. I could see the same thing happening to PBX vendors that had to change their entire architecture to accommodate new e911 requirements. Hosted PBX services, and PBX’s running multiple locations would most likely be the hardest to implement.

With FreePBX we can currently control 911 service by properly setting up outbound routes and trunks, and for multi-location systems, the Free Extensions Routing module allows you to easily define the proper route down to the handset/device level. But it also means when not using PSTN trunks you should be working with SIP trunk providers that pass 911 address information to the PSAP.

There is still plenty of room for error as a System Administrator that doesn’t understand the implications of providing proper emergency services configuration can leave their clients hanging when it comes time to make a call to 911.

We address these issues in our Open Telephony Training Seminar, and will also address it in our new FreePBX Certification program.

Take a look at adding the Free Extension Routing Module, then define Emergency Routes for your off site extensions (could be a problem if someone is using something such as a very portable softphone.) But for remote deskphones, you can provide a DID that is associated with just that location, and force the 911 call to go out that route, as well as restrict that route to only those devices at the remote location. Sure it’s going to cost you a few dollars per month for e911 service for just that DID, but that’s just a cost of doing business, and being able to sleep at night.


You certainly provided some great commentary. The only thing I will comment on though, is the perception that E911 is expensive or difficult to implement.

E911 is about sending the right caller ID down the right trunk group, based on the location of the user. The location can be determined by Layer 3, Layer 2, or manually provisioning.

NG911 is happening fast, and there are new mechanisms that will allow NG911 services to happen in an Over The Top model on the legacy network. The link to the presentation is on YouTube and although this is directed at Avaya customers, the concepts and principals are generic and applicable to almost any PBX.

A shorter (3 minute) version that just gets to the meat is located here:

Again, these are not sales videos, these are presentations I made to the FCC and other legislative and regulatory bodies to show them that E911, NG911 is not difficult to implement, there is more Myths out there than facts, and a little education can go a long way to implement E911.

As for Hosted E911, the VPC model is becoming more and more applicable as companies flatten and consolidate their locations to central data centers. VPC trunking from carriers like 911ETC, RedSky and others are becoming more and more popular and solve the geographic boundaries that the legacy E911 environments shackle our networks with.


Thanks for taking the time to stop by and comment on our humble Open Source site. Many of us “old school” telecom folks shudder at all of the folks who use our IP PBX to supply carrier type services. Frankly we have enabled an entire class of unregulated telcos that are putting their customers at risk.

The barriers to entry have been removed but the technical and regulatory onus is on the network operator. Purchasing a hosted instance of a PBX and connecting to a SIP provider does not make you a carrier.

For those of you who don’t know Mark works in NJ at what is left of Bell Laboratories. Bell Labs was the embodiment of American technical excellence and Mark walks the halls that were once traversed by the likes of Claude Shannon. If you are in the telecom business you owe it to yourself to know the history of Bell Labs (and Bellcore).

Mark, I believe we met in 2002/2003, I had an office in the Verizon Wireless NOC in Bedminster. I was working for Winphoria Networks with founders Murali Aravamudanand Guru Pai on a wireless soft switch trial, two ex Bell Labs guys that started Winphoria to explore the potential for Soft Switching.

Those were fun times, contributing to IETF SIP drafts and trying to explain how circuit switching days were numbered.

The power of an Open Source Class 4/5 switch in Asterisk, the ease of configuration with the FreePBX interface has been nothing short of revolution. I am glad that you follow our efforts and please stop by more often.

Best Regards…Scott


As I’m sure you are aware, there are multiple sides to the e911 equation, in the 90’s I was working in the wireless industry and about a week after e911 wireless requirements were made public a local PSAP in Viginia sent me notice wanting us to begin collecting e911 fees for implementation for wireless location in their area. Being a CDMA provider, the technology path was not even clear at that point, would location be tower based, phone based, etc. But the local PSAP knew they wanted that enhanced capability and moved on it quickly PSAP’s must make choices all the time as to what technology to implement for the public’s Safety.

Remember the cost of implementing these new technologies is not just on the PBX vendor side, the carrier side, but also the PSAP must keep up with the times.

As an example, last week in my area the local PSAP announced plans to upgrade their 911 center with the ability to send and receive sms/text messages. Just in the county I live in the cost of the network upgrades from the local carrier to enable that will be close to 20k per month for a new fiber backbone, over a ten year contract that’s two and a half million dollars. This cost does not include equipment upgrades or software upgrades to add that enhanced capability, or the marketing it will take to get the public on board and the future standardization and cooperation with other area PSAPs, to standardize sms emergency services, like 911.

All of this funding will be coming from the state 911 funds collected from telecom carriers, which in the end is collected from end users. This is just one county, multiply that across the number of PSAPs across the country. Then add in the cost of implementing PBX based location services you mention, it’s going to add incremental cost to vendors, but ultimately to the end users.

Cost aside, In situations such as campus environments where the phone system is supporting multiple locations across a several block radius, it does become more important to be able to closely associate a device with an address, or exact location, as opposed to just the PBX location or a generic address. This can be accomplished today in the FreePBX/Asterisk environment by several different methods, but like any PBX solution will ultimately depend on the telecom carrier and PSAP support as well.

I watched your video and sure it would be great to send additional data to the 911 center, but that center must also be able to support receiving that data.

I’m not certain that any PSAP would base adding technology based solely on a closed proprietary PBX system… but it’s not too late, you have found our little open source project, we welcome your experience on our forum.

Wow, that was a long time ago, but I clearly remember talking to you and a few other folks about the soft switch, and I think we discussed 911 call handling as well if memory serves me correctly.

I happened to catch the originating post on my Google E911 alert feed, and that is what brought me to the site. I try to make sure the myths and rumors don’t propagate too far, and that folks have a good understanding on their 911 configurations.

Good catching up with you, and another proof point of this business having deep roots. Stay well!

You raise many good points, and I am glad you see the value of my ‘little science project’ I presented to the CSRIC at the FCC.

As a matter of fact, there is a company that is in existence right now called They have have services in 300+ PSAPs across nearly 30 states, and the Public Safety industry LOVES THEM. They started to provide additional data for residences and cell phones, but I got them to develop an API for ANY PBX to talk to them over the internet, and they in turn communicate to the PSAP with the required encryption.

I just did a webinar on this for IAUG this past week. I am in the process of making it into a YouTube video, as the IAUG webinar is on the member side of and not publicly available.

Check out

I’ll investigate the smart911 api, thanks for sharing that.

I also suggest that people (especially the people that would be reading this forum) to research the capabilities of their local PSAPs, although not provided by an api, rather manually, My local 911 center has a 911 Dispatch Advisory Form on their website that allows you to add notes to the Dispatch System for your phone numbers and Physical address. Information includes:
Name, Phone Number, Physical Address, Apt#, Gate Code, House Description, Directions, Bedroom Location, Name and Emergency contact in case of an emergency at your location, location of a key, Major Medical History, regular medications, etc, Local Doctors Name, Doctors Phone Number, Pets, Pets Name, Type of Pet, IF THEY BITE. Additional information.

This information resets at the beginning of the June Each year, and is provided ONLY to emergency personnel in an emergency. Also according to state law in my area this information is protected from Freedom of Information Act request, so it’s about a private as anything you provide your local government.

I too use bulk911’s services and you can also set up your outbound routes with the emergency number route type ticked and match both 911 as well as 922 in the dial pattern since Bulk 911 uses 922 as a test number to read back your number and address to you for verification.

Then, if your extensions have the Emergency CID field defined, that Emergency CallerID will be sent to the trunk that matches the digits 911 and 922 which should be your bulk 911 trunk. (Dont forget to leave the CID field blank in the bulk 911 trunk since you need the extension to provide it from the emergency CID field.

Im not sure I would want to use an IVR to interrupt or delay a nervous, panicked or scared individual who expects to hear a friendly emergency operator after dialing 911, so Ill leave that up to you.

If you need anything custom beyond the FreePBX GUI, I highly recommend Visual Dialplan. It works beautifully with FreePBX and can build a custom outbound rule based on drag and drop objects so you literally “draw” your dialplan like a Visio diagram.