Feature Cheat Sheet

B2BUA Instance Originating / Terminating Point(s) in Session Plan Network Operator Data Subscriber Data Stateful or Stateless POJO Feature or SBB Feature Other notes

SCC

Terminating

SipAccess_SessionCheck

Yes

No

Stateless

SBB

Session input variables

Variable name Type Comments 
RegistrationRecords

List<RegistrationRecord>

The list of registration records for the subscriber, used to find the subscriber’s identity for the HLR lookup.

 
SentinelSelectionKey

SentinelSelectionKey

Used to retrieve configuration data for the feature.

 
Subscriber

String

Used to obtain the subscriber’s identity if it could not be determined from the registration data.

Session output variables

Variable name Type Comments 
MSRN

String

The MSRN of the served user, if the feature could retrieve it.

 
HasMSRN

boolean

Boolean indicating whether the MSRN session state field has been populated.

 
CallReferenceNumber

byte[]

The Call Reference Number used in the SRI request to the HLR.

 
VLRNumber

AddressString

The VLR number for the served user, if the feature could retrieve it.

Network Operator Data

The FetchMSRN feature depends on network operator data in two configuration profile tables. One is for feature specific configuration, the other is for general HLR connection configuration.

Feature Configuration

Feature specific configuration is set in a profile table called: SCCFetchMSRNConfigProfileTable. Profiles are scoped on Sentinel Selection Key.

SCCFetchMSRNConfigProfileTable

Attribute Type Default Value Meaning 
SuppressTcsi

boolean

 
true

If enabled the feature will set the Suppress_T_CSI flag in outgoing SRI requests.

 
ForceSipUserEqualsPhone

boolean

 
false

If true, when attempting to extract a number from a SIP URI, the feature will extract a number even if the URI does not have the user=phone parameter.

HLR Connection Configuration

The FetchMSRN feature uses the common HLR configuration profile table. See this page for details: HLR CGIN MAP Configuration.

Statistics

FetchMSRN statistics are tracked by the FetchMSRN SBB and can be found using the parameter set SLEE-Usage.Services.ServiceID[name=volte.sentinel.sip,vendor=OpenCloud,version=2.7.0].SbbID[name=scc-fetch-msrn-feature,vendor=OpenCloud,version=2.7.0]

Or in REM under the following parameter sets:
SLEE-Usage → Services → volte.sentinel.sip service → scc-fetch-msrn-feature SBB

Parameter Type Description 
Started

Counter

Incremented when the feature is invoked.

 
Failed

Counter

Incremented when a fatal error has occurred.

 
RequestSent

Counter

Incremented when a request is sent to the HLR.

 
RequestFailed

Counter

Incremented when a MSRN is not received from the HLR.

 
RequestReceivedAbsentSubscriber

Counter

Incremented if the HLR indicates that the requested subscriber is not CS attached.

 
RetrievedVLRNumber

Counter

Incremented if a VLR number is included in the result from the HLR.

 
RetrievedMSRN

Counter

Incremented when an MSRN is received from the HLR.

 
ResponseLatency

Sampled

Records elapsed time between sending the request to the HLR and getting a response (in milliseconds).

Behaviour

The feature issues a query to the HLR for the MSRN using the MAP operation Send Routing Info. The MAP Application Context used is locationInfoRetrievalContext_v3_ac.

When building the request to the HLR, the feature retrieves the "digits" portion of the IMS default public ID of the Served user from the first entry in the RegistrationRecords session state field. If this field does not contain digits, the "digits" portion of the subscriber ID is used.

Note that the feature does not use the entire ID, only the digits portion. Specifically, the feature will use the numbers in a Tel URI, or the user part of a SIP URI that has the 'user=phone' parameter if ForceSipUserEqualsPhone is false, or the user part of a SIP URI without the 'user=phone' parameter if ForceSipUserEqualsPhone is true.

Also while building the HLR request the feature will generate a Call Reference Number. This is then put into a header on the outgoing INVITE called OC-IM-CallReferenceNumber.

If the feature configuration option SuppressTcsi is enabled, then the Suppress_T_CSI flag will be set in the CamelInfo on the request. This will prevent the VLR number from being included in the response.

The HLR may return either a failure response, or a SendRoutingInfo-Res response containing the MSRN in the field ExtendedRoutingInfo.

If the feature is invoked, it increments the Started counter.

If any fatal error during the feature execution occurs, it increments the Failed counter.

If the feature is able to find an MSRN in the returned set, it increments the RequestSuccessful counter, and modifies the output session state variables. If there is a VLR number in the returned set, this will also be output to a session state variable.

If the returned set is empty, the feature increments the RequestFailed counter, and does not modify any output session state variables.

If the HLR returns a failure response, the feature increments the RequestFailed counter, and does not modify any output session state variables.

Previous page Next page
Sentinel VoLTE Version 2.7.0