In this section:
The
Multiple early dialogs at ingress leg when dialog transparency is enabled. It relays each forked 18x response received for the INVITE at egress leg towards the ingress leg by transparently passing the Call-ID, "From" tag, and "To" tag thus exposing multiple early dialogs at ingress leg.
The offer/answer negotiation on a forked call depends on the Packet Service Profile configured on either legs. As a result, SDP sent in the forked 18x response(s) towards ingress leg may vary depending on whether pass-through mode or transcoding mode is selected by the
The following diagram is an example call flow scenario for downstream forking with dialog transparency.
Call-ID and From tag are assumed to be same in all the responses shown in the above call flow.
Note
The SBC exposes multiple early dialogs on the ingress if multiple early dialogs are present on the egress due to downstream forking.
The Transparency Profile is the recommended method of configuring transparency on the SBC Core for new deployments as well as when applying additional transparency configurations to existing deployments. Do not use IP Signaling Profile flags in these scenarios because the flags will be retired in upcoming releases.
Refer to the SBC SIP Transparency Implementation Guide for additional information.
The
The
The parameters dialogTransparency
and downstreamForkingSupport
must be enabled to perform these functionalities.
The following diagram is an example call flow scenario for preserving early dialog context after 200 OK for INVITE.
The
The parameters dialogTransparency
and downstreamForkingSupport
must be enabled to perform these functionalities.
The following diagram is an example call flow scenario for support for UPDATE with codec change on inactive early dialog.
The
The parameters dialogTransparency
and downstreamForkingSupport
must be enabled to perform these functionalities.
The following diagram is an example call flow scenario for deactivating media resources when early dialogs do not exist.