AudioCodes Mediant 4000 SBC, User Manual

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CHAPTER 23 Configuring General SBC Settings
Mediant 4000 SBC | User's Manual
23 Configuring General SBC Settings
This section describes configuration of various SBC features.
Interworking Dialog Information in SIP NOTIFY
Messages
You can enable the device to interwork dialog information (XML body) received in SIP NOTIFY
messages from a remote (WAN) application server. The NOTIFY message is sent by application
servers to notify a SIP client, subscribed to a service and located behind the device (LAN), of the
status of another SIP client in the LAN. For example, user B can subscribe to an application server
for call pick-up service, whereby if user A's phone rings, the application server notifies user B. User
B can then press a pre-configured key sequence to answer the call.
The NOTIFY message contains the XML body with call identifiers (call-id and tags). However, as
the application server is located in the external network WAN and the SIP clients behind the
device, the call dialog information sent by the application server reflects only the dialog between the
device and itself; not that of the involved SIP clients. This is due to, for example, the device's
topology hiding (e.g., IP address) of its LAN elements. The device resolves this by replacing the
call identifiers received from the application server with the correct call identifiers (e.g., user A and
user B). Thus, users subscribed to the service can receive relevant NOTIFY messages from the
device and use the service.
➢
To enable the feature:
■ Configure the 'SBC Dialog-Info Interworking' (EnableSBCDialogInfoInterworking) parameter to
Enable .
When the feature is disabled, the device forwards the NOTIFY message as is, without modifying
its XML body.
Below is an example of an XML body where the call-id, tags, and URIs have been replaced by the
device:
<?xml version="1.0"?>
<dialog-info xmlns="urn:ietf:params:xml:ns:dialog-info"
version="10" state="partial"
entity="sip:alice@example.com">
<dialog id="zxcvbnm3" call-id="67402270@10.132.10.150"
local-tag="1c137249965"
remote-tag="CCDORRTDRKIKWFVBRWYM" direction="initiator">
<state event="replaced">terminated</state>
</dialog>
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