AudioCodes Mediant 4000 SBC, User Manual

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CHAPTER 28 Advanced SBC Features
Mediant 4000 SBC | User's Manual
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To configure SBC emergency call preemption:
1. In the Message Conditions table (see Configuring Message Condition Rules ), configure a
Message Condition rule to identify incoming emergency calls. See above for examples.
2. Open the SBC General Settings page ( Setup menu > Signaling & Media tab > SIP
Definitions folder > Priority and Emergency ), and then scroll down to the Call Priority and
Preemption group:
3. From the 'Preemption Mode' drop-down list (SBCPreemptionMode), select Enable to enable
call preemption.
4. In the 'Emergency Message Condition' field, enter the row index of the Message Condition rule
that you configured in Step 1.
5. (Optional) Assign DiffServ levels (markings) to packets belonging to emergency calls:
● In the 'Emergency RTP DiffServ' field (SBCEmergencyRTPDiffServ), enter the QoS level
for RTP packets.
● In the 'Emergency Signaling DiffServ' field (SBCEmergencySignalingDiffServ), enter the
QoS level for SIP signaling packets.
6. Click Apply .
Emergency Call Routing using LDAP to Obtain ELIN
The device can route emergency calls (e.g., 911) for INVITE messages that are received without
an ELIN number. This is in contrast to when the device is deployed in a Microsoft Skype for
Business environment, whereby INVITE messages received from Skype for Business contain
ELIN numbers. For a detailed explanation on ELIN numbers and handling of emergency calls by
emergency server providers, see
E9-1-1 Support for Microsoft Skype for Business .
To obtain an ELIN number for emergency calls received without ELINs, you can configure the
device to query an LDAP server for the 911 caller's ELIN number. The device adds the resultant
ELIN number and a Content-Type header for the PIDF XML message body to the outgoing INVITE
message, for example:
Content-Type: application/pidf+xml
<NAM>1234567890</NAM>
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To enable emergency call routing using LDAP to obtain ELIN:
1. Configure a Call Setup rule in the Call Setup Rules table (see Configuring Call Setup Rules ).
The following example shows a Call Setup rule that queries an Active Directory (AD) server for
the attribute "telephoneNumber" whose value is the E9-1-1 caller's number (source), and then
retrieves the user's ELIN number from the attribute "numberELIN":
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