In July of 2022, a drowning at a St. Louis County pool ended in the death of a 6-year old boy. The 911 call was routed to an Emergency Call Routing Center in Colorado, designed to answer and manually transfer 911 calls with failed location reporting. But the worst-case scenario occurred, and the call was delayed. READ The Story Here

Here is an explanation of how these scenarios can occur on modern MLTS phone systems.

Two hundred forty million calls go to 911 centers across the US each year, according to NENA, the 911 Association. How calls get there and information is collected and passed to Public Safety may shock you.

While the 911 system in the US is available across the country, it is not a single massive system. What looks like an umbrella of national coverage is a mesh of smaller localized 911 networks operating autonomously from each other. In some circumstances, agencies have established connectivity (where they share a common border), allowing them to pass data and transfer calls between them seamlessly. In most cases, however, the transfer of calls between agencies occurs through the standard telephone network, and data is often conveyed verbally.

With the popularity of VoIP, nomadic user behavior became commonplace. Nomadic user behavior was very different from mobile user behavior. Mobile users were continuously on the move, whereas nomadic users were better described as migratory, meaning these users would operate from a fixed position, migrate to a new location, and then operate from there for a period, only to move once again. The problem this introduces in an MLTS environment is that the core system needs to be sure of the location of the remote device to determine the appropriate 911 PSAP center (today referred to as an Emergency Communications Center or ECC) to send emergency call traffic to.

Another problem introduced is that each 911 network is often isolated from its peer networks. Call transfers are impossible, except for a standard call transfer over a regular public switched telephone line. While this seems to be a simple conference call problem to overcome, it is more complex. This is because the inbound telephone trunks to a 911 center are specialized (CAMA) trunks that originate from the regional 911 Selective Router and are reserved for inbound local 911 calls from the local network. In addition, inbound calls from outside the region must reach the ECC on administrative lines, which may not ring into dispatch, and are typically not monitored or staffed 24×7.

As VoIP devices became more commonplace and deployments grew larger and larger, the industry started to collapse and consolidate the infrastructure. This included moving many voice solutions to the cloud and much of their inbound and outbound telephone trunks. This exasperated the nomadic problem as with trunks in the cloud, local 911 call routing was impossible for the enterprise, as the localized E911 routing model logic was no longer possible.

To combat the issue quickly, some existing technology was expanded and used to provide a mechanism that would allow “long-distance 911 call routing” through a new carrier entity called a Voice Positioning Carrier (VPC). Mobile and Nomadic users without location information could be routed to these VPC Centers, where the Emergency Call Routing Center (ECRC) call takers would determine the caller’s location and then connect that caller with the appropriate 911 center local to them. In addition, MLTS users began taking advantage of these VPC ECRCs and routing ANY CALL that had a questionable location to the VPC ECRC, treating them as a safety net security blanket. While this sounds like a logical fix to the problem, it introduces a dangerous situation and what could end up as a fatal flaw in logic – literally.

Take the following into consideration about VPC ECRC Routing:

You’re MLTS has no idea of a station’s location. It must be TOLD through some process

The MLTS can have logic for calls with “no location” for VPC ECRC routing

The VPC ECRC Call Taker has no idea where the caller is – AT ALL

The location query is VERBAL, and the caller must communicate where they are

The VPC ECRC must then decide what agency serves that location

And now the shocking part that is rarely mentioned . . . .

In many cases (not all), the connection from the VPC ECRC to the 911 ECC is made via a typical 10-digit phone call to an administrative number that too often does NOT REACH the destination ECC or ring into the 911 center itself. This can cause delays, have calls go to voicemail (as the call did initially in this incident), or have a litany of other problems, not to mention the massive delay injected into the call process.

The VPC routes calls from known locations to ECCs in remote areas, so local trunking is not required in every 911 service area. The VPC ECRC service is better known as the ECC OF LAST RESORT. This means that no other physical entity exists that can handle or process the call or provide call handling. This is an important fact, and enterprises should not rely on this last-ditch resource to provide service to the emergency caller. So far too often, I see the attitude being taken to “Just let the VPC ECRC route the call . . . “and I’ll admit that before I fully understood what was happening there, it seemed like a viable option.

Therefore, this blog post’s purpose is not to scold but to educate. It is to help MLTS administrators better to understand the potential adverse outcomes of a particular action. Providing that education to those unaware of the problem is likely the best fix. Let’s face it; I don’t know anyone in the industry purposely trying to harm anyone. Additionally, these situations are not everyday occurrences or ones that there is vast knowledge around. They are the exception to the rule and one of the primary reasons 911 experts should be consulted on these issues.

Each year, I spend countless hours teaching consultants, engineers, and technicians how 911 functions and how NG911 changes the landscape. I would much rather spend time educating individuals to do the job properly than trying to figure out what they broke unintentionally, especially when a death is involved. At that point, it is far too late. I’ll reiterate my standing offer to anyone:

If your team would like a personalized webinar or in-person session on how 911 works, examples of solutions that can be deployed costing $0 and up depending on functionality and complexity, I am happy to provide this to you in-person or online at ZERO COST to you or your organization (other than travel expense, of course). I have been a NENA Certified Emergency Number Professional for nearly the past two decades; I am the author of Kari’s Law and a contributor to the FCC on the defining language in the RAY BAUM’S Act, both of which are now Federal Law under the US Code of Federal Legislation Title 47.

I’m here to help . . . . and I’m always here to talk.

VP Public Safety Solutions
911inform, LLC


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