Suspend and Resume Notification for Pure-S Calls

Revision History


Note

Revision history details are not provided for features introduced before release 21.24.

Revision Details

Release

First introduced

Pre 21.24

Feature Description

Suspend and Resume Notifications for Pure-S calls are now supported in the CUPS architecture. The User Plane (UP) and Control Plane (CP) communicate through the Sx Establishment/Modification request when a Suspend/Resume notification is received.

Ongoing streams are maintained on the UP. When a Suspend/Resume notification is received, the CP changes the FAR action on UP through the Sx Modification request message. In response, the UP sets the appropriate FAR action.

On receiving a Modify Bearer request after a suspend notification, if an eNodeB TEID exists in the MBReq, the mode is set to Forward in the FAR. If the eNodeB TEID does not exist, then the mode is set to BUFFER.

How It Works

For a Suspend notification, downlink data is suspended by setting downlink FAR action to DROP. For a Resume notification, downlink data is buffered by setting downlink FAR action to BUFFER.

Call Flows

Suspend Notification

On receipt of a Suspend notification in Pure-S call, the SGW-C updates the Download FAR action by sending Sx Session Modification request to SGW-U with FAR action set as DROP.

The following call flow, at a high level, illustrates the Suspend notification for Pure-S calls

Resume Notification

On receipt of Resume notification in Pure-S call, the SGW-C updates the Download FAR action by sending Sx Session Modification request to SGW-U with FAR action set as BUFFER.

The following call flow, at a high level, illustrates the Resume notification for Pure-S calls.