This feature sends SIP MESSAGE requests to instruct superfluous session removal .
For an architectural view of co-ordinating signalling anchors refer to Shared ATU-STI.
Feature cheat sheet
| B2BUA Instance | SAS Support | Originating / Terminating | Point in Session Plan | Network Operator Data | Subscriber Data | Stateful or Stateless | POJO Feature or SBB Feature |
|---|---|---|---|---|---|---|---|
SCC |
Yes |
Originating and Terminating |
|
Yes |
No |
Stateless |
POJO |
Network Operator Data
Network configuration is stored in a JSLEE profile table named SCCCoordinateSignallingAnchorsConfigProfileTable.
| Parameter | Type | Default Value | Description |
|---|---|---|---|
|
int |
|
Time in milliseconds to wait between receiving the access transfer ACK and sending out SIP MESSAGEs to remove superfluous sessions. |
Session input variables
| Variable | Type | Description |
|---|---|---|
ASURI |
String |
The URI of this SCC node loaded by SCCDetermineSessionType |
AccessTransferACKed |
boolean |
Set by SCCProcessHandoverInsideAnchor to indicate that the Access Transfer INVITE has been ACK’d. |
SuperfluousSessions |
Set<TrackedSession> |
The set of TrackedSessions that will be removed. A SIP MESSAGE is sent for each entry. Set by SCCDetermineTransferableSet. |
Statistics
SCCCoordinateSignallingAnchors statistics are tracked by the sentinel.volte.sip SBB
and can be found under the following parameter set in REM:
SLEE-Usage → sentinel.volte.sip service → sentinel.volte.sip SBB → feature → SCCCoordinateSignallingAnchors
or with rhino-stats:
"SLEE-Usage.Services.ServiceID[name=sentinel.volte.sip,vendor=OpenCloud,version=3.0.0].SbbID[name=sentinel.volte.sip,vendor=OpenCloud,version=3.0.0].feature.SCCCoordinateSignallingAnchors"
| Name | Description |
|---|---|
Started |
Incremented each time the feature runs |
FailedToStart |
Incremented when a fatal error occurs before feature execution |
IssuedWarning |
Incremented when a non-fatal error occurs during feature execution |
FailedDuringExecution |
Incremented when a fatal error occurs during feature execution |
TimedOut |
Incremented when feature execution does not complete within a reasonable time frame |
TimerStarted |
Incremented when the feature starts the timer |
TimerFired |
Incremented when the feature receives the timer event |
TimerCanceled |
Incremented when the feature cancels the timer |
SentSuperfluousSessionMessage |
Incremented when the feature sends a SIP MESSAGE request to a remote node to remove a superfluous session |
SentSuperfluousSessionMessageInternally |
Incremented when the feature sends a SIP MESSAGE event internally to remove a superfluous session |
CouldNotFindInternalTargetSession |
Incremented when the target session could not be found |
Behaviour
The feature is first triggered when an Access Transfer is completed by receiving an ACK for the handover INVITE. When the ACK is received,
the SCCProcessHandoverInsideAnchor feature sets the session state flag AccessTransferACKed.
When that flag is TRUE, this feature will arm a timer with the value in CoordinateSessionsDelay.
Then when either the timer fires, or the session is ending the feature will construct a SIP MESSAGE for each TrackedSession in SuperfluousSessions.
These MESSAGEs are sent to trigger SCCRemoveSuperfluousSession on the node in control of those sessions.
The MESSAGE will have the following headers set:
| Header Name | Header Value |
|---|---|
|
The |
|
The |
|
The |
|
The |
|
|
|
The |
