Section: 13.3 Detection and handling of requests which have timed out at the originating entity 13.3.1 General
Content: This procedure enables an entity which receives a request to know when the request times out at the originating entity, and to stop further processing, at the receiver and further upstream entities, a request which has timed out at the originating entity. The originating entities (i.e. MME, SGSN, TWAN and ePDG) and the receiving entities (i.e. SGW, PGW, PCRF, 3GPP AAA Server) shall be NTP synchronized. This procedure may be used between entities pertaining to the same PLMN, and if allowed by operator policy, between entities pertaining to different PLMNs. This procedure shall not affect the setting of the retransmission timers by intermediate entities. E.g. the SGW shall set its T3 and N3 retransmission parameters as specified in this specification, irrespective of the time at which the request times out at the originating entity.