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Configuring Teams to Comply with RAY BAUM’s 911 Act


The RAY BAUM (Repack Airwaves Yielding Better Access for Users of Modern Services) Act was enacted on August 1, 2019. The Act is designed to ensure that a dispatchable location is provided automatically to the Public Safety Access Point (PSAP) when an emergency services call is placed from a Multi Line Telephone System (MLTS). Dispatchable locations must consist of the validated street address of the emergency services caller plus additional information to adequately identify the caller’s location such as floor, suite, apartment, etc. The Act went into effect on February 16, 2020. Their are two (2) deadlines for compliance:

         1. January 6, 2021
  • Applies to on-premises fixed devices associated with a MLTSambulance
  1. January 6, 2022
  • Adds the requirement that non-fixed devices and off-premises devices associated with an MLTS must be in compliance

State and municipal laws and regulations can supersede Federal laws, as long as they are not inconsistent with them.

Automatic Provisioning of Dispatchable Locations to Emergency Services

  • The act requires that “dispatchable locations” must be automatically provided to Emergency Services when a 911 call is placed
  • For on-premises non-fixed devices and off-premises devices, the location must be provided automatically where technically feasible otherwise the information can be based on end user manual update or enhanced location information
  • Teams can automatically provide a user’s current location for on-premises fixed and non-fixed devices.
    • It cannot currently provide this for off-premises devices found in a remote worker’s home or when signed on to the Teams Mobile Client while connected to a public WIFI hotspot
  • Teams does not currently have a built-in mechanism to allow users to manually update their current location. On-premises Microsoft Lync and Skype for Business have this capability
    • There are third party tools that can provide this functionality such as mye911 from RedSky Technologies
  • Enhanced location information refers to the use of coordinates or Geocodes (latitude and longitude) to determine a location. It is commonly believed that Microsoft will be adding the ability to identify the location of an emergency services caller by Geocodes if they are not connected to an internal network. At this time, no documentation could be found for this
  • The discussion of what constitutes a “dispatchable location” is covered in the first blog in this series. There are several factors used to determine what the appropriate definition of dispatchable locations are for an organization

Delivering the Location information to the Emergency Services Call Center

  • If a Microsoft Teams Calling Plan or Direct Routing user makes an emergency services call that does not have a dispatchable location, the call will be redirected to a live agent. The agent will ask the caller for their current location and will route the call to the appropriate Public Safety Answering Point (PSAP). PSAPs are also referred to as Emergency Services Call Centers
  • This would be the case for remote Teams workers and the customer’s Teams users calling from an external network.

Microsoft Teams Calling Plan Users

  • Microsoft Teams will deliver the dispatchable location information for Microsoft Teams Calling Plan users directly to the PSAP
  • This is a default configuration for Calling Plan users requiring no additional administration by the customer
  • If the call does not have a dispatchable location, the call will be redirected by Microsoft to a live agent in the Emergency Call Response Center (ECRC). The agent will ask the caller for their current location and will route the call and the location to the appropriate Public Safety Answering Point (PSAP).
  • This would be the case for remote Teams workers and the customer’s Teams users calling from an external network. This is covered in more detail in the first blog article in this series.

Microsoft Teams Direct Routing Users

  • Microsoft Teams will add the dispatchable location information to the Session Description Protocol (SDP) section of the SIP INVITE to the customer’s Teams Direct Routing Session Border Controller (SBC) when a Teams Direct Routing user makes an emergency call. This information is referred to as the Presence Information Data Format – Location Object (PIDF-LO). It is presented in the Extensible Markup Language (XML) format
  • An Emergency Location Identification Number (ELIN) is a Phone Number that is defined in a table and associated with a dispatchable location. It is an alternative method for delivering an emergency caller’s current dispatchable location to the PSAP
  • ELIN numbers can be defined in Teams Emergency Address and Location\Place records. If a Location\Place record has an ELIN, it will override the ELIN of the parent Emergency Address record

Routing to the PSAP using the PIDF-LO Dispatchable Location Information

  • If the client is not using ELINs, they must engage a third-party Emergency Routing Services Provider (ERSP) to handle emergency calls passed from Teams to the SBCs
  • The customer would establish an interface from the SBC to the ERSP. This will usually be over a dedicated SIP Trunk connection
  • Using the connection to the ERSP, the customer will configure the router to send the emergency call including the PIDF-LO information to the ERSP. The ERSP will “read” the dispatchable location information in the PIDF-LO and will automatically route the emergency caller to the appropriate PSAP. The SIP INVITE sent to the ERSP by the SBC will have the emergency caller’s Source\Calling Number in the SIP “From” field and the emergency number, “911” in the United States, in the “To” field
  • If the call does not have a dispatchable location, the call will usually be redirected to a live agent at the ERSP. The agent will ask the caller for their current location and will route the call and the location to the appropriate Public Safety Answering Point (PSAP). Each ERSP may handle these calls differently. The customer should consider this when evaluating ERSPs

Routing to the PSAP using an ELIN to reference the Dispatchable Location

  • Emergency Call routing by ELIN may be available to the customer from their telephony provider. Some SIP Trunk providers offer this service as an option. This service is also available from some ERSPs
  • There are a few additional required configuration steps to use ELINs instead of the PIDF-LO information to refer to the current dispatchable location of a Teams Direct Routing emergency caller:
    1. The customer will have to allocate and assign unique telephone numbers to each of their Teams Emergency Address and Location\Place records referring to a dispatchable location. These will have to be Direct Inward Dial (DID) numbers. These numbers must be DIDs in case the PSAP needs to call the emergency caller back should the original call get disconnected
    2. The ELIN numbers must be added to the appropriate Teams Emergency Address and Location\Place records. As a reminder, Teams Emergency Address records cannot be modified once created. This includes adding, changing, or deleting the ELIN number. For this reason, it is recommended when using ELINs to put the ELIN numbers on the Location\Place records instead of the Emergency Address records
    3. The information with the validated address of the dispatchable location and the assigned phone number will have to be provided to the telephony provider or ELIN in a format defined by them
    4. The SBCs will have to be configured to “handle” ELIN numbers in emergency calls. For some SBC vendors this requires the purchase of an “ELIN” license. On most SBCs there will be a switch(es) or setting(s) that will need to be modified to support the use of ELINs
  • The customer will configure the SBC to send the emergency call to the telephony provider or ERSP. To send the ELIN the SBC (this is true for AudioCodes SBCs and is likely true for other vendors products) will place the emergency caller’s Calling Name and Source\Calling number in the “P-Asserted Identity” field of the SIP INVITE. The ELIN number will be placed in the “From” field of the SIP INVITE and the emergency number, “911” in the United States, in the “To” field
  • The telephony provider on receipt of the call will look up the ELIN number in the customer database to get the dispatchable location of the Teams Direct Routing emergency services caller. The provider will use the location information to direct the call to the appropriate PSAP
  • The customer should check with their ELIN provider to see how they will handle calls that do not have provide an ELIN

Configuration Requirements for Automatically Providing current Dispatchable Locations

  • To enable this functionality for Microsoft Teams Calling Plan and Microsoft Teams Direct Routing users, you will have to configure:
    • Teams Emergency Addresses
    • Teams Emergency Locations\Places
    • Teams Tenant Trusted IP Addresses
    • One or more of the Network Elements in the Teams Location Information System (LIS) Database
  • The configuration for Teams Direct Routing users will also require:
  • Configuration of at least one (1) Teams Emergency Call Routing Policy with “Dynamic Emergency Calling” enabled
  • Connecting the SBC(s) to an ERSP who can “read” the dispatchable location information provided by Teams or to a telephony vendor who can route the call based on the ELIN is the responsibility of the customer

Teams Component Configuration

Teams Emergency Addresses and Locations\Places

  • Teams Emergency Addresses will have to be added for all Microsoft Teams Calling Plan remote workers. These will be these user’s home addresses
  • Generally, Teams Emergency Addresses should be added for all of an organization's buildings
  • Additional Teams Locations\Places will be added based on the Company’s determination of appropriate dispatchable locations for emergency calling. These will be floors, Conference Rooms, Offices etc. within an organization's buildings

Teams Tenant Trusted IP Addresses

  • Required for determining an Emergency Services caller’s location to be provided to a PSAP for Microsoft Teams Calling Plan users or ERSP for Microsoft Teams Direct Routing users
  • If you are using location-based scoping of Teams Emergency Calling or Emergency Call Routing policies, you will have already added these addresses to Teams
  • Teams Tenant Trusted IPs are used to determine whether the caller is making an Emergency Services call from an internal network
  • An IPv4 Tenant Trusted IP record should be added for all routers, firewalls, or other perimeter devices that provide user access to the Internet
  • Entries can be made for single IP addresses or a range based on the address and a subnet mask
  • Microsoft recommends that both an IPv4 and IPv6 address for these devices be added to the Tenant Trusted IP table
    • If not already configured, the client should ask their Internet Service Provider (ISP) to provision an IPv6 address for their devices providing Direct Internet Access (DIA) to their users.
    • These can be single IPv6 addresses or ranges with subnet masks like the IPv4 addresses. All addresses should be statically provided by the ISPs
    • The device will have to be configured to listen for and send traffic using IPv6
    • The client’s internal networks do not need to be configured to support IPv6 addressing or routing

Teams Location Information System (LIS) Database and Network Elements

  1. The Teams Local Information System Database (LIS) is used to determine an emergency caller’s current location and provide that information to the PSAP or ERSP when making an emergency services call! It is truly what makes 911 calling dynamic!
  2. At its heart, the LIS allows us to associate a defined Teams Location\Place to a network element in the LIS database:
    • Network Subnets
    • The Basic Service Set IDs of Wireless Access Points
    • MAC addresses of network switches
    • Specific ports on network switches
  3. The ultimate question for the LIS Database is whether to use Subnets, Wireless Access Point, Switches or Switch Ports, or a combination of these, to identity the current location of a user when they make an Emergency Services call
  4. There are three (3) required steps to answer this question:
    • Review any applicable State or Municipal laws and regulations that define what a dispatchable location is
    • Discuss with your corporate counsel, risk and compliance managers and human resources department their definition of dispatchable location requirement. This level could exceed the regulatory requirement
    • Work with the corporate IT team to determine how to provide the required level of dispatchable location based on the configuration of the elements of the network infrastructure
  5. The process to determine this required level of dispatchable location is discussed in more detail in the first blog in this series

Adding Tenant Trusted IP Addresses

Teams Admin Center

1. In the Teams Admin Center click on “Locations” then “Network topology” then the “Trusted IPs” tab. Click the “Add” button


2. Click the “IP Version” drop down and select “IPv4” or “IPv6”
3. Enter the IP Address in the “IP address” field
4. Put the subnet mask in the “Network Range” field
5. Add a description as required

6. Click the “Apply” button



Teams PowerShell Module

  • Teams Tenant Trusted IP addresses can be added through the Teams Online PowerShell Module
  • To create a new Tenant Trusted IP address, you will need to use the New-CsTenantTrustedIPAddress command
  • If you are going to add these with a PowerShell Script, you will need a Comma Separated Value file with the required information properly formatted

Adding Location Information System Database Records

  • Add the required Emergency Addresses and Location\Places before adding network elements to the LIS database
  • It is easier to add and manage these records in the Admin Center because you can refer to the Locations\Places by their Location Names. When using PowerShell commands, you must reference the Location\Place records by their LocationIDs
  • An emergency services caller’s current location could match more than one network element. A location could match on a port, switch, and subnet if these records are configured in the LIS Database. The order of precedence when there is a match for more than one network element is:
    • Port
    • Switch
    • Subnet
  • If you have a lot of network elements to define, a PowerShell Script that references a Comma Separated Value (CSV) file would be the tool of choice
  • The Teams PowerShell commands to manage the LIS are:
    • Subnets
    • Wireless Access Point
    • Switches
    • Wireless Access Point
    • There is no “New-Cs” PowerShell command for any of these elements in the LIS database. If you use the “Set-Cs” command and there is no record for the element and a Location, it will be created. If the record exists, it will be overwritten
    • There is one very important note about configuring subnets in the LIS Database. When you add a subnet to the LIS Database there is no field for the subnet’s mask. The reason for this is due to how a user’s subnet is identified when placing an emergency services call.
      • When a user makes an emergency services call, the Teams client will gather the IP address and subnet mask configured for the endpoint. The Teams client will use this information to determine the user’s subnet and attempt to match it to an LIS subnet record.
        • For example:
          • A user’s machine has an IP address of with a 23-bit mask (
          • Applying the mask to the IP address will result in the IP address falling within the range of through with a subnet ID of
          • If you added a subnet record to the LIS database for, the endpoint’s IP address and subnet mask would never make a match in the LIS Database
          • For this endpoint, an LIS subnet record for would result in a match

Using Teams Admin Center to Add Network Elements 

To add network elements to the LIS database in the Teams Admin Center:

1. Click on “Locations” then “Networks and Locations”. Select the type of element you want to add then click the “Add” button


2. For each element you will need to add:
    • The identifier such as the subnet or the chassis ID of a switch. The subnet element also requires the type of subnet (IPv4 or IPv6) while the Port element requires the switch Chassis ID and Port ID
    • The Location\Place to associate with the element
    • An optional, but recommended, description of the element

3. Click the “Apply” button


Teams PowerShell to add Network Elements


  • The RAY BAUM Act went into effect on February 16, 2020 and applies to all MLTS sold or installed after this date
  • It requires that a dispatchable location be provided to the PSAP when a user places an emergency call from an MLTS
  • All on-premises fixed devices were required to be in compliance as of January 6, 2021
  • Non-fixed on-premises and all off-premises devices are required to be in compliance by January 6, 2022
  • Teams can provide dispatchable locations for on-premises devices
  • The process to configure Teams to provide these locations for Teams Calling Plan and Direct Routing users is almost the same. Teams Direct Routing requires a few additional steps and integration with an ERSP or a SIP Trunk provider who can route calls to a PSAP based on an ELIN

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We hope this information was valuable to you. If you need a deeper dive, here’s John’s Dynamic 911 whitepaper in full for your viewing to answer any other questions of concerns you may have. 

Teams Dynamic 911 and Dynamic 911 for Work from Home

Work with our team of Cloud Computing Consultants who have done this so many times they know all of the “minefields” to prevent missteps.