The MMTelStodProcessHandover feature intercepts the transfer INVITE routed by the MMTelStodTriggerAnchor feature and connects the existing called led to the new calling leg and releases the previous calling leg .
Feature Cheat Sheet
| B2BUA Instance | SAS Support | Originating / Terminating | Point(s) in Session Plan | Network Operator Data | Subscriber Data | Stateful or Stateless | POJO Feature or SBB Feature | Other notes |
|---|---|---|---|---|---|---|---|---|
MMTel |
No |
Both |
|
No |
Stateful |
SBB Feature |
Session Input Variables
| Session State variable name | Type | Comments |
|---|---|---|
CallType |
enum |
MobileOriginating or MobileTerminating |
Statistics
MMTelStodProcessHandover 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 → MMTelStodProcessHandover
or with rhino-stats:
"SLEE-Usage.Services.ServiceID[name=sentinel.volte.sip,vendor=OpenCloud,version=4.0.0].SbbID[name=sentinel.volte.sip,vendor=OpenCloud,version=4.0.0].feature.MMTelStodProcessHandover"
| Name | Incremented when… |
|---|---|
Started |
the feature runs |
FailedToStart |
Sentinel VoLTE encounters an error while attempting to start the feature |
IssuedWarning |
a non-fatal problem is encountered and the feature issues a warning |
FailedDuringExecution |
a fatal problem is encountered and the feature cannot execute correctly |
TimedOut |
the feature takes too long to complete and Sentinel VoLTE aborts execution |
SentRemoteUpdate |
a re-INVITE is sent to the called party. |
RemoteUpdateSuccess |
re-INVITE was accepted (200 OK). |
RemoteUpdateError |
re-INVITE was not accepted. |
CallAnsweredWith200 |
the (200 OK) from the re-INVITE is sent to the new access leg |
ReleasedOldAccessLeg |
the previous calling leg is released |
LinkedNewAccessLegToRemoteLeg |
the transfer INVITE leg is linked to the existing called party leg |
TerminatedSession |
the session finishes |
AccessTransferComplete |
the session transfer was done successfully |
HandoverRequestReceived |
a session transfer INVITE is received |
StodEnableSessionTracking |
tries to mark the new transfered session to be tracked |
FoundTrackingKey |
the tracking key is set |
StodSessionTrackingDisabled |
when failed to set the new transfered session to be tracked |
Behaviour
The feature intercepts the transfer INVITE routed by the MMTelStodTriggerAnchor feature and connects the existing called leg to the new calling leg and releases the previous calling leg.
The feature also does the SDP remote update by sending the transfer INVITE as a reINVITE on the existing called leg and guarantees the SDP integrity and correctness on all involved dialogs.
Source
For source code information see MMTel Session Transfer Source Code
