5.18 HPLMN Notification with specific indication due to MME initiated Bearer removal
23.4013GPPGeneral Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) accessRelease 18TS
When initiating a Delete Session Request procedure, the MME shall add an appropriate cause code facilitating the operator of the P-GW to take appropriate action (e.g. Alarm, O&M action by operator’s management network) if needed.
NOTE: This is for the HPLMN operator to be able to differentiate Delete Session Request procedures due to a failure case (e.g. due to a QoS parameter mismatch at Initial Attach) from Delete Session Request procedures that are executed in cases not related to any failure conditions (e.g. due to a Tracking Area Update). Action taken by the HPLMN operator is outside the scope of 3GPP specification.