Section: 7.3.20 ISR Status Indication
Content: A ISR Status Indication message shall be sent on the S3 interface by the MME/SGSN to the ISR associated SGSN/MME as part of the following procedures: - the Restoration of PDN connections after an SGW failure for UEs with ISR as specified in 3GPP TS 23.007[ Restoration procedures ]  [17]; - the HSS Based P-CSCF restoration procedure for 3GPP access (for both basic and PCO extension) as specified in 3GPP TS 23.380[ IMS Restoration Procedures ]  [61]. Table 7.3.20-1 specifies the presence of the IEs in the message. Table 7.3.20-1: Information Elements in an ISR Status Indication