Section: 7.9.5 PGW Restart Notification
Content: The direction of this message shall be from SGW to MME/S4-SGSN (see Table 6.1-1). If both the SGW and the MME/S4-SGSN support the PRN feature (see clause 8.83), a PGW Restart Notification shall be sent when the SGW detects that the peer PGW has restarted, and a PGW Restart Notification may be sent when the SGW detects that the peer PGW has failed and not restarted, as specified in 3GPP TS 23.007[ Restoration procedures ]  [17]. Table 7.9.5-1 specifies the presence of IEs in this message. Table 7.9.5-1: Information Elements in PGW Restart Notification