This feature analyses an incoming INVITE request to determine if it is a USSI request.
Feature cheat sheet
| Feature Name | Network Operator Data | Used in PlanId(s) | Stateful or Stateless | POJO Feature or SBB Feature |
|---|---|---|---|---|
DetermineUssiMode |
No |
All INVITE Sessions |
Stateless |
POJO |
Statistics
DetermineUssiMode statistics are tracked by the sentinel.ipsmgw SBB
and can be found under the following parameter set in REM:
SLEE-Usage → sentinel.ipsmgw service → sentinel.ipsmgw SBB → feature → DetermineUssiMode
or with rhino-stats:
"SLEE-Usage.Services.ServiceID[name=sentinel.ipsmgw,vendor=OpenCloud,version=3.1.0].SbbID[name=sentinel.ipsmgw,vendor=OpenCloud,version=3.1.0].feature.DetermineUssiMode"
| Name | Description |
|---|---|
Started |
Incremented when the feature is started. |
FailedToStart |
Incremented when Sentinel encounters an error while attempting to start the feature. |
IssuedWarning |
Incremented when a non-fatal problem is encountered and the feature and issues a warning. |
FailedDuringExecution |
Incremented when a fatal problem is encountered and the feature cannot execute correctly. |
TimedOut |
Incremented when the feature takes too long to complete and Sentinel aborts execution. |
MessageNotUssiRequest |
Incremented when it is determined that the incoming request is not a USSI request. |
MessageIsUssiRequest |
Incremented when it is determined that the incoming request is a USSI request. |
Behaviour
On receiving an incoming SIP request, this feature checks the request against the following conditions:
-
The request method is
INVITE. -
The Request-URI is a SIP URI (i.e. the URI starts with
sip:). -
The Request-URI has a
userparameter with the value set todialstring. -
The user part of the Request-URI is a valid USSD dial string according to 3GPP TS 22.090.
If all of the conditions are met, the feature will increment the MessageIsUssiRequest statistic and finish execution, allowing message processing to proceed.
If any of the conditions are not met, the feature will increment the MessageNotUssiRequest statistic, and instruct the SIP session to proxy the request without recording Sentinel on the route.
The feature will then finish execution.
