This feature receives a CAP trigger, stores re-origination information, and is able to forward the call such that it is routed into the IMS .
It enables processing circuit-switched originating calls in the SCC-AS.
The related feature is SCCCamelToIMSReOriginationSIP; these features are part of service centralization in the IMS. For this feature’s fit into the overall flow, please see the Re-origination basic flow diagram.
Feature cheat sheet
| B2BUA Instance | Originating / Terminating | Point in Session Plan | Network Operator Data | Subscriber Data | Stateful or Stateless | POJO Feature or SBB Feature |
|---|---|---|---|---|---|---|
This feature is IN only, it does not exist in a SIP B2BUA |
Mobile Originating and Mobile Terminating only |
Session_PreInitialCreditCheck |
Yes. See Correlation RA |
No |
Stateless |
1 POJO for IN behaviour |
Network operator data
Network configuration data is stored in a JSLEE configuration profile table named SCCCamelToIMSReOriginationConfigProfileTable.
The IN feature shares network operator configuration with the SCCCamelToIMSReOriginationSIP feature.
This data is scoped by Sentinel selection key. In other words, each network operator will have one entry in this table.
For more information, see the shared configuration between the IN and SIP feature.
Use of Correlation resource adaptor
For information about use of the Correlation RA, please see the shared Correlation RA.
Statistics
SCCCamelToIMSReOriginationIN statistics are tracked by the volte.sentinel.ss7 SBB and can be found under the following parameter set:
SLEE-Usage → volte.sentinel.ss7 service → volte.sentinel.ss7 SBB → feature → SCCCamelToIMSReOriginationIN
| Parameter | Type | Description |
|---|---|---|
Started |
Counter |
Incremented when the feature starts. |
FailedToStart |
Counter |
Incremented when the feature failed to start due to an error. |
IssuedWarning |
Counter |
Incremented when the feature raised a warning. |
FailedDuringExecution |
Counter |
Incremented when the feature failed due to a major error. |
TimedOut |
Counter |
Incremented when the feature timed out during execution. |
CallReOriginated |
Counter |
Incremented when the call is successfully re-originated. |
CallReleased |
Counter |
Incremented when reorigination fails and the call is released. |
Misconfigured |
Counter |
Incremented when the feature has not been correctly configured. |
IdpVlrNumberPresent |
Counter |
Incremented when the VLR number is found in the incoming InitialDP. |
IdpVlrNumberNotPresent |
Counter |
Incremented when the VLR number is not found in the incoming InitialDP. |
VisitedNetworkIdNotFound |
Counter |
Incremented when the feature is unable to determine the Visited Network ID. |
VisitedNetworkIdFound |
Counter |
Incremented when the feature is able to determine the Visited Network ID based on the VLR address. |
PoolAllocationFailed |
Counter |
Incremented when the feature fails to acquire a correlation ID from the correlation RA. |
PoolAllocationSucceeded |
Counter |
Incremented when the feature acquires a correlation ID from the correlation RA. |
OriginatingIMRNAttempt |
Counter |
Incremented when the feature executes reorigination for an originating call leg. |
TerminatingIMRNAttempt |
Counter |
Incremented when the feature executes reorigination for a terminating call leg. |
Behaviour
The feature is triggered with an Initial DP. If the call type is not Mobile Originating or Mobile Terminating, the feature finishes execution without modifying any state.
The feature checks if the Initial DP is a CAMEL initial DP. If not, it finishes executing without modifying any state.
It then checks network configuration, and if not present it informs Sentinel that it failed to execute, with an invalid configuration cause. It then finishes execution.
Once configuration is loaded, it attempts to re-originate the call (that is, forward the call into the IMS). This works as per the re-origination section.
Re-originating the call
The IDP is checked for the presence of the CalledPartyBCDNumber. If not present, the call is treated as per the Failure to re-originate section.
Following that, the feature uses the Visited Network ID Address List to check that there is a known Visited Network ID for the VLR address present in the IDP location information. If there is a matching ID, the feature will continue processing as normal. If there is no matching ID the feature will terminate the call as per the Failure to re-originate section. The purpose of this is to avoid wasting resources establishing the SIP side of the call, only to have it fail when the SIP reorigination feature is unable to find a matching Visited Network ID.
The feature then consults the Correlation resource adaptor entity in order to allocate a re-origination address. This is an address that is used for routing the call onwards. The Correlation resource adaptor entity stores both the correlation number allocation, and the key fields of the CAP Initial DP argument. These are used later, in the SIP feature.
The feature then builds a destination routing address, using the address returned by the Correlation RA, and the network configuration for the address’s Nature, RoutingToInternalNetworkNumber, and NumberingPlan fields.
The network configuration for a prefix is used if the network configuration indicates a prefix is required.
This address is called the “IP Multimedia Routing Number”, or IMRN for short.
It then creates a new Connect operation, using the IMRN in the Destination Routing Address field, and requests sending of the Connect and a close of the TCAP dialog.
| If | Then |
|---|---|
there are any problems with any of:
|
the call is treated according to Failure to re-originate and a |
