ANNEX A (to Recommendation Q.714) State diagrams for the signalling connection control part of Signalling System No. 7 A.1 Introduction This Annex contains the definitions for the symbols used and defines the states of the signalling point X/Y interface and the transitions between states in the normal case. Annex B contains the full definition of actions, if any, to be taken on the receipt of messages by a signalling point. A.2 Symbol definition of the state diagrams at the message interface between two nodes (signalling points: X and Y) (see Figures A-1/Q.714 and A-2/Q.714) Figure A-1/Q.714 CCITT 19172 Figure A-2/Q.714 - CCITT 73120 A.3 Order definition of the state diagrams For the sake of clarity, the normal procedure at the interface is described in a number of small state diagrams. In order to describe the normal procedure fully, it is necessary to allocate a priority to the different figures and to relate a higher order diagram with a lower one. This has been done by the following means: - Figures A-3/Q.714, A-4/Q.714, A-5/Q.714 and A-6/Q.714 are arranged in order of priority, with Figure A-3/Q.714 having the highest priority and subsequent figures having lower priority. Priority means that when a message belonging to a higher order diagram is transferred, that diagram is applicable and the lower order one is not. - The relation with a state in a lower order diagram is given by including that state inside an ellipse in the higher order diagram. - The message abbreviations are those defined in Recommendation Q.712. Figure A-3/Q.714 - CCITT 19192 Fascicle VI.7 - Rec. Q.714 PAGE33 Figure A-4/Q.714 - CCITT 19201 Figure A-5/Q.714 - CCITT 73131 Figure A-6/Q.714 - CCITT 19210 ANNEX B (to Recommendation Q.714) Action tables for the signalling connection control part of Signalling System No. 7 B.1 Introduction This Annex contains the definitions for the symbols used and contains the full definition of actions, if any, to be taken on the receipt of messages by a signalling point (node). Annex A contains the full definition of states of the signalling point X/Y interface and the transitions between states in the normal case. B.2 Symbol definition of the action tables The entries given in Table B-1/Q.714 and B-2/Q.714 indicate the action, if any, to be taken by a SP on receipt of any kind of message, and the state the SP enters, which is given in parentheses, following the action taken. PAGE96 Fascicle VI.7 - Rec. Q.714 In any state it is possible to receive an Error message (ERR). The reaction, if any, depends on the contents (error cause and possible diagnostics) of the message and is specified in Q.714, S 3.10.3. The reaction on messages received with procedure errors (e.g. too long, invalid P(R), not octet aligned, etc.) are normal actions and will be described in the text. So they are covered by the actions indicated as NORMAL. B.3 Table of contents Table B-1/Q.714 Actions taken by SP-Y on receipt of messages. Table B-2/Q.714 Actions taken by SP-Y on receipt of messages with known message type and containing mismatch information. Table B-3/Q.714 Actions taken by SP-Y on receipt of messages during connection establishment and release phases. Table B-4/Q.714 Actions taken by SP-Y on receipt of messages during the data transfer phase in a given state: reset. Table B-5/Q.714 Actions taken by SP-Y on receipt of messages during the data transfer phase in a given state: data expedited data, flow control. TABLE B-1/Q.714 Action taken by SP-Y on receipt of messages State of the interface as perceived by node Any state SP-Y Message received by node SP-Y Any message with unknown message type (see DISCARD Note) Any message with known message type and: See Table B-2/Q.714 a)unassigned destination local reference number, or b)Originating Point Code received not equal to the PC stored locally, or c)source local reference number received not equal to the remote local reference number stored locally Any other message See Table B-3/Q.714 DISCARD: SP-Y discards the received message and takes no subsequent action Note - This notion of unknown message type depends upon the protocol class TABLE B-2/Q.714 Action taken by SP-Y on receipt of messages with known message type and containing mismatch information as in Table B-1/Q.714 in any state Type of mismatch information Unassigned Source local Originating Point Message destination local reference number Code received not received by node PS-Y reference number received not equal equal to the PC to the one stored stored locally locally (see Note 1) CR (X) N.A. N.A. N.A. Fascicle VI.7 - Rec. Q.714 PAGE33 CC (Y, X) Send ERR (X) (see N.A. N.A. Note 2) CREF (Y) DISCARD N.A. N.A. RLSD (Y, X) Send RLC (X, Y) Send ERR (X) Send ERR (X) (see Note 2) (see Note 2) (see Note 2) RLC (Y, X) DISCARD DISCARD DISCARD DT1 (Y) DISCARD N.A. C.O.N.P. DT2 (Y) DISCARD N.A. C.O.N.P. AK (Y) DISCARD N.A. C.O.N.P. ED (Y) DISCARD N.A. C.O.N.P. EA (Y) PAGE96 Fascicle VI.7 - Rec. Q.714 DISCARD N.A. C.O.N.P. RSR (Y, X) Send ERR (X) Send ERR (X) Send ERR (X) (see Note 2) (see Note 2) (see Note 2) RSC (Y, X) Send ERR (X) Send ERR (X) Send ERR (X) (see Note 2) (see Note 2) (see Note 2) ERR (Y) For further study For further study For further study IT (Y, X) DISCARD RELEASE C.O.N.P DISCARD: SP-Y discards the received message and takes no subsequent action. C.O.N.P. Check Optionally Not Performed. N.A. Not Applicable NAME (d, s): NAME = abbreviation of message d = destination local reference number s = source local reference number. Note 1 - Performing this check is a national option. Note 2 - In this situation no action is taken locally on any existing connection section. Information in any message sent back is taken from the received message. Fascicle VI.7 - Rec. Q.714 PAGE33 TABLE B-3/Q.714 Action taken by SP-Y on receipt of messages during connection establishment and release phases State of the interface Signalling connection control ready: r1 as perceived by node SP-Y Message Ready SP-X SP-Y Data SP-X SP-Y received connecti connecti transfer disconne disconne by note SP-Y c1 on on ct ct pending pending c4 pending pending c2 c3 c5 c6 Connexion request NORMAL See Note (CR) (c2) Connection confirm DISCARD NORMAL DISCARD ERROR 1 DISCARD (CC) (c2) (c4) (c4) (c6) (c6) Connection refused DISCARD NORMAL DISCARD ERROR 1 DISCARD (CREF) (c2) (c1) (c4) (c6) (c6) Released (RLSD) See DISCARD ERROR 2 NORMAL DISCARD Table (c2) (c3) (c5) B-2/Q.71 4 PAGE96 Fascicle VI.7 - Rec. Q.714 (c5) NORMAL (c1) Released complete DISCARD ERROR 3 DISCARD ERROR 1 NORMAL (RLC) (c2) (c1) (c4) (c6) (c1) Other messages DISCARD ERROR 3 See ERROR 1 DISCARD (c2) (c1) Table (c6) (c6) B-4/Q.71 4 NORMAL: The action taken by SP-Y follows the normal procedures as defined in the appropriate sections of the procedure text. DISCARD: SP-Y discards the received message and takes no subsequent action. ERROR 1: SP-Y discards the received message and initiates a connection release by sending a RLSD message with proper invalid type cause. ERROR 2: SP-Y returns a Released complete message using information contained in the message and takes no subsequent action. ERROR 3: SP-Y discards the received message and releases locally. Note - Reception of CR in these states is note possible because CR does not contain a destination local reference number (no search is performed). Fascicle VI.7 - Rec. Q.714 PAGE33 TABLE B-4/Q.714 Action taken by node SP-Y as receipt of messages during the data transfer state State of the interface as Data transfer: c4 perceived by node SP-Y Data SP-X SP-Y Message received by node SP-Y control reset reset ready request request (d1) (d2) (d3) Reset request (RSR)(see Note 2) NORMAL DISCARD NORMAL (d2) (d2) (d1) Reset confirmation (RSC)(see Note 2) ERROR ERROR NORMAL (d3) (d3) (d1) Other messages See ERROR DISCARD Table (d3) (d3) B-5/Q.71 (see 4 Note 1) NORMAL:The action taken by SP-Y follows the normal procedures as defined in the appropriate sections of the procedure text. DISCARD:Signalling point Y discards the received message and takes no subsequent action. ERROR:Signalling point Y discards the received message and initiates a reset by transmitting a reset request message with the appropriate cause indication. Note 1 - If signalling point Y issues a reset by transmitting a reset request message as a result of an error condition in state d2, it should eventually consider the interface to be in the Data control ready state (d1). Note 2 - Reception of these messages for a class 2 connection section may trigger the sending of an ERR message back if these message types are known by the receiving SCCP. TABLE B-5/Q.714 Action taken by SP-Y on receipt of messages during the data control ready state State of the interface as perceived by node SP-Y Data control ready: d1 Normal SP-X SP-Y SP-X and data expedite expedite Message received by node SP-Y flow d data d data e1 e2 e3 PAGE96 Fascicle VI.7 - Rec. Q.714 SP-Y expedite d data e4 Expedited data (ED) NORMAL ERROR NORMAL ERROR (d2) (d3) (d4) (d3) Expedited data (EA) acknowledgement DISCARD DISCARD NORMAL NORMAL (e1) (e2) (e1) (e2) Data (DT), data acknowledgement (AK) and NORMAL NORMAL NORMAL NORMAL Inactivity Test (IT) (e1) (e2) (e3) (e4) NORMAL:The action taken by signalling point Y follows the normal procedures as defined in the appropriate sections of the procedure text. DISCARD:Signalling point Y discards the received message and takes no subsequent action as direct result of receiving that message. ERROR:Signalling point Y discards the received message packet and indicates a reset by transmitting a reset request message with the appropriate cause indication (e.g. procedure error). Note - Reception of an ED, EA, DT2 or AK message for a class 2 connection section will cause the receiving SCCP to DISCARD any of these messages. A DT1 message received for a class 3 connection section will also be discarded. Fascicle VI.7 - Rec. Q.714 PAGE33 ANNEX C (to Recommendation Q.714) State transition diagrams (STD) for the signalling connection control part of Signalling System No. 7 C.1 General This annex contains the description of the main SCCP functions (except SCCP management (SCMG) which is contained in annex D to Recommendation Q.714) according to the CCITT Specification and Description Language (SDL). For the SCCP as a whole, Figure 1/Q.714 illustrates a subdivision into functional blocks, showing their functional interactions as well as the functional interactions with the other major functions of signalling system No. 7 (e.g. MTP). The functional breakdown shown in this diagram is intended to illustrate a reference model, and to assist interpretation of the text of the SCCP procedures. The state transition diagrams are intended to show precisely the behaviour of the signalling system under normal and abnormal conditions as viewed from a remote location. It must be emphasized that the functional partitioning shown in the following diagrams is used only to facilitate understanding of the system behaviour, and is not intended to specify the functional partitioning to be adopted in a practical implementation of the signalling system. C.2 Drafting conventions Each major function is designated by its acronym (e.g. SCOC = SCCP connection-oriented control). External inputs and outputs are used for interactions between different functional blocks. Included within each input and output symbol in the state transition diagrams are acronyms which identify the functional blocks which are the source and the destination of the message, e.g.: SCRC ® SCOC indicates that the message is sent from SCCP routing control to SSCP connection-oriented control Internal inputs and outputs are only used to indicate control of timers. C.3 Figures The list of figures is as follows: Figure C-1/Q.714 SCCP routing control procedures (SCRC). Figure C-2/Q.714 Connection establishment and release procedures at originating node for SCCP connection-oriented control (SCOC). (Sheets 1 to 3: connection establishment, and sheets 4 to 6: connection release procedures) Figure C-3/Q.714 Connection establishment and release procedures at destination node for SCCP connection-oriented control (SCOC). (Sheets 1 to 2: connection establishment, and sheets 3 to 5: connection release procedures) Figure C-4/Q.714 Data transfer procedures at originating and destination nodes for SCCP connection-oriented control (SCOC). Figure C-5/Q.714 Expedited data transfer procedures at originating and destination nodes for SCCP connection-oriented control (SCOC). Figure C-6/Q.714 Reset procedures at originating and destination nodes for SCCP connection-oriented control (SCOC). PAGE96 Fascicle VI.7 - Rec. Q.714 Figure C-7/Q.714 Connection establishment and release procedures at intermediate node for SCCP connection-oriented control (SCOC). (Sheets 1 to 4: connection establishment, and sheets 5 to 9: connection release procedures) Figure C-8/Q.714 Data transfer procedures at intermediate node for SCCP connection-oriented control (SCOC). Figure C-9/Q.714 Expedited data transfer procedures at intermediate node for SCCP connection-oriented control (SCOC). Figure C-10/Q.714 Reset procedures at intermediate node for SCCP connection-oriented control (SCOC). Figure C-11/Q.714 Restart procedure for SCCP connection-oriented control (SCOC). Figure C-12/Q.714 SCCP connectionless control (SCLC). C.4 Abbreviations and timers Abbreviations and timers used in Figures C-1/Q.714 to C-11/Q.714 are listed below. Abbreviations CR Connection Request DPC Destination Point Code GT Global Title IT Inactivity Test MSG Message MTP Message Transfer Part NPDU Network Protocol Data Unit NSDU Network Service Data Unit PC Point Code SCCP Signalling Connection Control Part SCLC SCCP Connectionless Control SCMG SCCP Management SCOC SCCP Connection-Oriented Control SCRC SCCP Routing Control SLS Signalling Link Selection SS Sub-System SSN Sub-System Number SSPC Sub-System Prohibited Control Timers T(conn est) Waiting for connection confirm message. T(ias) Delay to send a message on a connection section. T(iar) Waiting to receive a message on a connection section. T(rel) Waiting for release complete message. T(int) Waiting to report abnormal release to maintenance function. T(guard) Waiting to resume normal procedures for temporary connection Fascicle VI.7 - Rec. Q.714 PAGE33 sections during the restart procedure PAGE96 Fascicle VI.7 - Rec. Q.714 Figure C-1/Q.714 (feuillet 1 sur 3) - T1114960-88 Figure C-1/Q.714 (feuillet 2 sur 3) - T1114970-88 Figure C-1/Q.714 (feuillet 3 sur 3) - T1114980-88 Figure C-2/Q.714 (feuillet 1 sur 6) - T1114990-88 Figure C-2/Q.714 (feuillet 2 sur 6) - T1115000-88 Figure C-2/Q.714 (feuillet 3 sur 6) - T1115010-88 Figure C-2/Q.714 (feuillet 4 sur 6) - T1115020-88 Figure C-2/Q.714 (feuillet 5 sur 6) - T1115030-88 Figure C-2/Q.714 (feuillet 6 sur 6) - T1115040-88 Figure C-3/Q.714 (feuillet 1 sur 5) - T1115050-88 Figure C-3/Q.714 (feuillet 2 sur 5) - T1115060-88 Figure C-3/Q.714 (feuillet 3 sur 5) - T1115070-88 Figure C-3/Q.714 (feuillet 4 sur 5) - T1115080-88 Figure C-3/Q.714 (feuillet 5 sur 5) - T1115090-88 Fascicle VI.7 - Rec. Q.714 PAGE33