O.5 Handling of unknown, unforeseen, and erroneous protocol data
24.0083GPPCore network protocolsMobile radio interface Layer 3 specificationRelease 18Stage 3TS
O.5.1 General
The following subclauses specifies procedures for the handling of unknown, unforeseen, and erroneous protocol data by the receiving MS. These procedures are called "error handling procedures", but in addition to providing recovery mechanisms for error situations they define a compatibility mechanism for future extensions of the protocols.
Subclauses O.5.2 to O.5.5 shall be applied in order of precedence.
For the definition of semantical and syntactical errors see 3GPP TS 24.007 [20], subclause 11.4.2.
Where the description of information elements in the present document contains bits defined to be "spare bits", these bits shall set to the indicated value (usually 0) by the sending side, and their value shall be ignored by the receiving side.
O.5.2 Not supported IEs, unknown IEIs
The MS shall ignore all information elements which are not supported and all information elements with unknown IEI.
O.5.3 Repeated IEs
If an information element, for which repetition is not specified in subclause O.2, is repeated in the user-user protocol contents, only the contents of the information element appearing first shall be handled and all subsequent repetitions of the information element shall be ignored. When repetition of information elements is specified, only the contents of specified repeated information elements shall be handled. If the limit on repetition of information elements is exceeded, the contents of information elements appearing first up to the limit of repetitions shall be handled and all subsequent repetitions of the information element shall be ignored.
O.5.4 Syntactically incorrect IEs
The MS shall treat all IEs that are syntactically incorrect as not present in the user-user protocol contents.
O.5.5 Semantically incorrect IEs
When an IE with semantically incorrect contents is received, the foreseen reactions specified for the respective procedure are performed (e.g. in the context of CSI see 3GPP TS 24.279 [116], clauses 5, 6). If however no such reactions are specified, the MS shall ignore the IE.
Annex P (normative):
Mobility management for IMS voice termination