AudioCodes Mediant 500 E-SBC, User Manual

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User's Manual 26. Configuring Supplementary Services
Version 6.8 425 Mediant 500 E-SBC
The figure below illustrates an AudioCodes ELIN Gateway deployed in the Lync Server
2010 environment for handling E9-1-1 calls between the Enterprise and the PSTN.
Figure 26-4: AudioCodes ELIN Gateway for E9-1-1 in Lync Server 2010 Environment
26.5.2.3.1 Detecting and Handling E9-1-1 Calls
The ELIN Gateway identifies E9-1-1 calls and translates their incoming E9-1-1 calling
numbers into ELIN numbers, sent toward the PSAP. The ELIN Gateway handles the
received E9-1-1 calls as follows:
1. The ELIN Gateway identifies E9-1-1 calls if the incoming SIP INVITE message
contains a PIDF-LO XML message body. This is indicated in the SIP
Content-Type
header, as shown below:
Content-Type: application/pidf+xml
2. The ELIN Gateway extracts the ELIN number(s) from the "NAM" field in the XML
message. The "NAM" field corresponds to the <CompanyName> column in the
Location Information Server (LIS). The ELIN Gateway supports up to five ELIN
numbers per XML message. The ELINs are separated by a semicolon. The digits of
the ELIN number can be separated by hyphens (xxx-xxx-xxx) or they can be adjacent
(xxxxxxxxx), as shown below:
<ca:NAM>1111-222-333; 1234567890 </ca:NAM>
3. The ELIN Gateway saves the From header value of the SIP INVITE message in its
ELIN database table ( Call From column). The ELIN table is used for PSAP callback,
as discussed later in ''PSAP Callback to Lync 2010 Clients for Dropped E9-1-1 Calls''
on page
427 . The ELIN table also stores the following information:
•
ELIN: ELIN number
•
Time: Time at which the original E9-1-1 call was terminated with the PSAP
•
Count: Number of E9-1-1 calls currently using this ELIN