Passing Location Information To The Pstn Emergency Provider - AudioCodes E-SBC User Manual

CHAPTER 16 Services
<ChassisID>,<Description>,<Location>,<CompanyName>, <HouseNum-
ber>,<HouseNumberSuffix>,<PreDirectional>,<StreetName>,<StreetSuffix>,
<PostDirectional>, <City>,<State>,<PostalCode>,<Country>
For the ELIN number to be included in the SIP INVITE (XML-based PIDF-LO message) sent by the
Mediation Server to the ELIN device, the administrator must add the ELIN number to the
<CompanyName> column (shown in the table above in bold typeface). As the ELIN device
supports up to five ELINs per PIDF-LO, the <CompanyName> column can be populated with up to
this number of ELINs, each separated by a semicolon. The digits of each ELIN can be separated by
hyphens (xxx-xxx-xxx) or they can be adjacent (xxxxxxxxx). When the ELIN device receives the
SIP INVITE, it extracts the ELINs from the NAM field in the PIDF-LO (e.g., <ca:NAM>1111-222-
333; 1234567890 </ca:NAM>), which corresponds to the <CompanyName> column of the LIS.
If you do not populate the location database, and the Skype for Business location policy, Location
Required is set to Yes or Disclaimer, the user will be prompted to enter a location manually.

Passing Location Information to the PSTN Emergency Provider

When a Skype for Business client, enabled for E9-1-1 emergency services, dials 9-1-1, the location
data and callback information stored on the client is sent with the call through the Mediation Server
to a SIP Trunk-based or PSTN-based emergency service provider. The emergency service provider
then routes the call to the nearest and most appropriate PSAP based on the location information
contained within the call.
Skype for Business passes the location information of the Skype for Business client in an IETF-
standard format - Presence Information Data Format - Location Object (PIDF-LO)–in a SIP INVITE
message. However, this content cannot be sent on the SIP Trunk or PSTNsince they do no support
such a content. To overcome this, Enterprises deploying the device can divide their office space
into Emergency Response Locations (ERLs) and assign a dedicated Emergency Location
Identification Number (ELIN) to each ERL (or zone). When Skype for Business sends a SIP
INVITE message with the PIDF-LO to the device, it can parse the content and translate the calling
number to an appropriate ELIN. The device then sends the call to the SIP Trunk or PSTN with the
ELIN number as the calling number. The ELIN number is sent to the emergency service provider,
which sends it on to the appropriate PSAP according to the ELIN address match in the ALI
database lookup.
The ERL defines a specific location at a street address, for example, the floor number of the
building at that address. The geographical size of an ERL is according to local or national
regulations (for example, less than 7000 square feet per ERL). Typically, you would have an ERL
for each floor of the building. The ELIN is used as the phone number for 911 callers within this ERL.
The figure below illustrates the use of ERLs and ELINs, with an E9-1-1 call from floor 2 at the
branch office:
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