Section: 14.3 Handling of Bearer Context Mismatch 14.3.1 General
Content: The following requirements should apply: 1) When an EPC entity receives a response message, where one or more dedicated bearer context(s) is associated with the Cause code "Context Not Found" while the PDN connection is known by the peer, the EPC entity shall delete the corresponding bearer context(s); 2) When an SGW receives a Modify Bearer Request, where one or more dedicated bearer context(s) is missing in the request message in comparison to the Bearer Context(s) stored for the UE's PDN connection, the SGW shall accept the Modify Bearer Request message and delete the corresponding bearer context(s) locally. The PGW shall apply the same behavior if the Modify Bearer Request received at the PGW includes the Bearer Contexts to be modified IE; 3) When a SGW receives a Modify Bearer Request, where only one or more dedicated bearer context(s) is unknown, the SGW shall accept the Modify Bearer Request message partially and set the cause code "Context Not Found" for those unknown bearer context(s) at Bearer Context level. The PGW shall apply the same behavior if the Modify Bearer Request received at the PGW includes the Bearer Contexts to be modified IE; 4) When a SGW receives a Modify Access Bearer Request, where one or more dedicated bearer context(s) is missing in the request message in comparison to the Bearer Context(s) stored for all the UE's PDN connections, the SGW shall delete the corresponding bearer context(s) locally; 5) When a SGW receives a Modify Access Bearer Request, where only one or more dedicated bearer context(s) is unknown, the SGW shall accept the Modify Access Bearer Request message partially and set the cause code "Context Not Found" for those unknown bearer context(s) at Bearer Context level. NOTE: It is assumed the PGW can at least use a subsequent Modify Bearer Request to resolve Bearer Context mismatch, so that the SGW need not send explicit message to delete unknown Bearer Context.