Section: 6.4.2.4 Dedicated EPS bearer context activation not accepted by the UE
Content: Upon receipt of the ACTIVATE DEDICATED EPS BEARER CONTEXT REQUEST message, the UE may reject the request from the MME by sending an ACTIVATE DEDICATED EPS BEARER CONTEXT REJECT message. The message shall include the EPS bearer identity and an ESM cause value indicating the reason for rejecting the dedicated EPS bearer context activation request. The ACTIVATE DEDICATED EPS BEARER CONTEXT REJECT message contains an ESM cause that typically indicates one of the following ESM cause values: #26: insufficient resources; #31: request rejected, unspecified; #41: semantic error in the TFT operation; #42: syntactical error in the TFT operation; #43: invalid EPS bearer identity; #44: semantic error(s) in packet filter(s); #45: syntactical error(s) in packet filter(s); or #95 – 111: protocol errors. The UE shall check the TFT in the request message for different types of TFT IE errors as follows: a) Semantic errors in TFT operations: 1) When the TFT operation is an operation other than "Create a new TFT" The UE shall reject the activation request with ESM cause #41 "semantic error in the TFT operation". b) Syntactical errors in TFT operations: 1) When the TFT operation = "Create a new TFT" and the packet filter list in the TFT IE is empty. 2) When there are other types of syntactical errors in the coding of the TFT IE, such as a mismatch between the number of packet filters subfield, and the number of packet filters in the packet filter list. The UE shall reject the activation request with ESM cause #42 "syntactical error in the TFT operation". c) Semantic errors in packet filters: 1) When a packet filter consists of conflicting packet filter components which would render the packet filter ineffective, i.e. no IP packet will ever fit this packet filter. How the UE determines a semantic error in a packet filter is outside the scope of the present document. 2) When the resulting TFT does not contain any packet filter which applicable for the uplink direction. The UE shall reject the activation request with ESM cause #44 "semantic errors in packet filter(s)". d) Syntactical errors in packet filters: 1) When the TFT operation = "Create a new TFT" and two or more packet filters in the resultant TFT would have identical packet filter identifiers. 2) When the TFT operation = "Create a new TFT" and two or more packet filters in all TFTs associated with this PDN connection would have identical packet filter precedence values. 3) When there are other types of syntactical errors in the coding of packet filters, such as the use of a reserved value for a packet filter component identifier. In case 2, if the old packet filters do not belong to the default EPS bearer context, the UE shall not diagnose an error, shall further process the new activation request and, if it was processed successfully, shall delete the old packet filters which have identical filter precedence values. Furthermore, by means of explicit peer-to-peer signalling between the network and the UE, the UE shall perform a UE requested bearer resource modification procedure to delete the packet filters in the network corresponding to the packet filters it has deleted on the UE side. In case 2, if one or more old packet filters belong to the default EPS bearer context, the UE shall release the relevant PDN connection. If the relevant PDN connection is the last one that the UE has and EMM-REGISTERED without PDN connection is not supported by the UE or the MME, the UE shall detach and re-attach to the network. In cases 1 and 3 the UE shall reject the activation request with ESM cause #45 "syntactical errors in packet filter(s)". Upon receipt of the ACTIVATE DEDICATED EPS BEARER CONTEXT REJECT message in state BEARER CONTEXT ACTIVE PENDING, the MME shall stop the timer T3485, enter the state BEARER CONTEXT INACTIVE and abort the dedicated EPS bearer context activation procedure. The MME also requests the lower layer to release the radio resources that were established during the dedicated EPS bearer context activation procedure.