Section: 5.2.1.2 Receipt of a setup message
Content: In the "null" or "recall present" states, upon receipt of a setup message (a SETUP message or an EMERGENCY SETUP message, see subclause 5.2.1.1), the call control entity of the network enters the "call initiated" state. It shall then analyse the call information contained in the setup message. In Iu mode, network shall include the SI received in the SETUP message into the RABid and send it back to the mobile station. For RABid see 3GPP TS 25.413[ UTRAN Iu interface Radio Access Network Application Part (RANAP) signalling ]  [19c] and 3GPP TS 44.118[ None ]  [111]. If the network receives the SETUP message with no SI, the network shall set the SI value to 1. i) If, following the receipt of the setup message, the call control entity of the network determines that the call information received from the mobile station is invalid (e.g. invalid number), then the network shall initiate call clearing as defined in subclause 5.4 with one of the following cause values: # 1 "unassigned (unallocated) number", # 3 "no route to destination", # 22 "number changed", # 28 "invalid number format (incomplete number)". ii) If, following the receipt of the setup message, the call control entity of the network determines that a requested service is not authorized or is not available, it shall initiate call clearing in accordance with subclause 5.4.2 with one of the following cause values: # 8 "operator determined barring", # 57 "bearer capability not authorized", # 58 "bearer capability not presently available", # 63 "service or option not available, unspecified", or # 65 "bearer service not implemented". iii) Otherwise, the call control entity of the network shall either: - send a CALL PROCEEDING message to its peer entity to indicate that the call is being processed; and enter the "mobile originating call proceeding" state; - or: send an ALERTING message to its peer entity to indicate that alerting has been started at the called user side; and enter the "call received" state; - or: send a CONNECT message to its peer entity to indicate that the call has been accepted at the called user side; and enter the "connect request" state. The call control entity of the network may insert bearer capability information element(s) in the CALL PROCEEDING message to select options presented by the mobile station in the Bearer Capability information element(s) of the SETUP message. The bearer capability information element(s) shall contain the same parameters as received in the SETUP except those presenting a choice. Where choices were offered, appropriate parameters indicating the results of those choices shall be included. The CALL_PROCEEDING message shall also contain the priority of the call in the case where the network supports eMLPP. Mobile stations supporting eMLPP shall indicate this priority level to higher sublayers and store this information for the duration of the call for further action. Mobile stations not supporting eMLPP shall ignore this information element if provided in a CALL PROCEEDING message. NOTE: If the network supports only R98 or older versions of this protocol and the priority is not included in the CALL PROCEEDING message, this does not imply that the network does not support eMLPP. - The CALL_PROCEEDING message shall contain the multicall supported information in the network call control capabilities in the case where the network supports multicall and there are no other ongoing calls to the MS. Mobile stations supporting multicall shall store this information until the call control state for all calls returns to null. Mobile stations not supporting multicall shall ignore this information if provided in a CALL PROCEEDING message. If the multicall supported information is not sent in the CALL_PROCEEDING message, the mobile station supporting multicall shall regard that the network doesn't support multicall. The call control entity of the network having entered the "mobile originating call proceeding" state, the network may initiate the assignment of a traffic channel according to subclause 5.2.1.9 (early assignment). For speech calls, if the SETUP message or EMERGENCY SETUP message contains a Supported Codec List information element, the network shall use this list to select the codec for UTRAN. If no Supported Codec List information element is received, then for UTRAN the network shall select the default UMTS speech codec according to subclause 5.2.1.11. Codecs for GERAN shall be selected from the codecs indicated in the Supported Codec List information element or in the Bearer Capability information element. If neither a Supported Codec List information element nor a Bearer Capability information element is received, then for GERAN the network shall select GSM full rate speech version 1. Codec information that does not apply to the currently serving radio access shall be used by the network if an inter-system change occurs. Figure 5.2/3GPP TS 24.008[ Mobile radio interface Layer 3 specification; Core network protocols; Stage 3 ]  Mobile originated call initiation and possible subsequent responses.