Section: 12.3.7 Updating the PGW with overload control information of the target MME/S4-SGSN
Content: During inter-MME/S4-SGSN mobility without SGW change scenarios, the SGW shall forward the MME/S4-SGSN's overload control information over the S5/S8 interface only if the Modify Bearer Request message needs to be sent over the S5/S8 for another reason, e.g. if the ULI, CGI, Serving Network, needs to be reported to the PGW, i.e. the SGW shall not generate a Modify Bearer Request message over the S5/S8 interface for the sole purpose of reporting the MME/S4-SGSN's overload control information. This avoids generating extra signalling over the S5/S8 interface. NOTE: If the MME/S4-SGSN provides overload control information during the scenarios which do not result in S5/S8 signaling, e.g. during an inter MME/S4-SGSN and intra SGW mobility, when no other information such as: the ULI, CGI or Serving Network, needs to be reported to the PGW, the overload information will not be relayed on to the PGW. Hence, the MME/S4-SGSN needs consider this when including overload control information.