AudioCodes Mediant 1000B - Passing Location Information to the PSTN Emergency Provider

User's Manual 296 Document #: LTRT-27055
Mediant 1000B Gateway & E-SBC
Network
Element
Columns
x>,<PostDirectional>,<City>,<State>,<PostalCode>,<Country>
Switch
<ChassisID>,<Description>,<Location>,<CompanyName>,<HouseNumber>,<HouseNu
mberSuffix>,<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.
15.7.2.3 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 PSTN
network since 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: