Dialogic® Vision™ CX Video Gateway Administration Manual
SIP interface
Inbound calls
An inbound call (SIP to PSTN) is initiated through a SIP INVITE. The SDP
Offer/Answer model (RFC 3264) is used for media negotiation. The INVITE usually
contains the offer, and the 200 OK response contains the answer SDP.
The following table lists the possible responses to the SIP INVITE:
Response
Description
200 OK
Success.
480 Temporarily Unavailable
Call not authorized.
503 Service Unavailable
No channels available to take call.
By default, the CX Video Gateway handles incoming DTMF content in the following
manner:
•
If RFC 2833 is negotiated, then the gateway obtains the DTMF tone and
duration through an RFC 2833 DTMF event.
•
If RFC 2833 is not negotiated, then the gateway obtains the DTMF tone and
duration from the body of the SIP INFO message.
If the joined connection is a SIP connection, then audio transcoding automatically
occurs between the two endpoints, when required.
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