1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Q.713 (03/2001) SERIES Q: SWITCHING AND SIGNALLING Specifications of Signalling System No. 7 - Signalling connection control part (SCCP) Signalling connection control part formats and codes ITU-T Recommendati
2、on Q.713 (Formerly CCIlT Recommendation) ITU-T Q-SERIES RECOMMENDATIONS SWITCHING AND SIGNALLING SIGNALLING IN THE INTERNATIONAL MANUAL SERVICE FUNCTIONS AND INFORMATION FLOWS FOR SERVICES IN THE ISDN INTERNATIONAL AUTOMATIC AND SEMI-AUTOMATIC WORKING CLAUSES APPLICABLE TO ITU-T STANDARD SYSTEMS SPE
3、CIFICATIONS OF SIGNALLING SYSTEMS No. 4 AND No. 5 SPECIFICATIONS OF SIGNALLING SYSTEM No. 6 SPECIFICATIONS OF SIGNALLING SYSTEM R1 SPECIFICATIONS OF SIGNALLING SYSTEM R2 DIGITAL EXCHANGES INTERWORKING OF SIGNALLING SYSTEMS SPECIFICATIONS OF SIGNALLING SYSTEM No. 7 General Message transfer part (MTP)
4、 Signalling connection control part (SCCP) Telephone user part (TUP) ISDN supplementary services Data user part Signalling System No. 7 management ISDN user part Transaction capabilities application part Test specification * 0 s, Q3 INTERFACE DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1 PUBLIC LAND MO
5、BILE NETWORK INTERWORKING WITH SATELLITE MOBILE SYSTEMS INTELLIGENT NETWORK Q.l-Q.3 Q.4-Q.59 Q.6O-Q.99 Q.10O-Q.119 Q. 120-Q.249 Q.25O-Q.309 4.3 10-Q.399 Q.400-Q.499 Q.50O-Q.599 Q.700-Q.799 4.700 Q.701-Q.709 Q.7114.719 4.720-4.729 4.730-4.739 4.740-4.749 4.7504.759 4.760-4.769 4.7704.779 4.780-4.799
6、Q. 800-Q. 849 Q.85O-Q.999 Q. 100O-Q. 1 O99 Q. 1 100-Q. 1 199 Q. 1200-4.1699 Q.600-Q.699 SIGNALLING REQUIREMENTS AND PROTOCOLS FOR IMT-2000 Q. 1700-Q. 1799 SPECIFICATIONS OF SIGNALLING RELATED TO BEARER INDEPENDENT CALL Q. 1900-Q. 1999 CONTROL (BICC) BROADBAND ISDN Q.20OO-Q.2999 For further details,
7、please refer to the list of ITU-T Recommendations. ITU-T Recommendation Q.713 Signalling connection control part formats and codes Summary This Recommendation specifies the Signalling Connection Control Part (SCCP) messages formats and codes for the purpose of connection-oriented services, connectio
8、nless services and management of SCCP. Source ITU-T Recommendation Q.713 was revised by ITU-T Study Group 11 (2001-2004) and approved under the WTSA Resolution 1 procedure on 1 March 2001. ITU-T Q.713 (03/2001) i FOREWORD The International Telecommunication Union (ITU) is the United Nations speciali
9、zed agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a wo
10、rldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in
11、 WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with IS0 and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication admi
12、nistration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applic
13、ability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implem
14、ent this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. o ITU 2001 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means,
15、electronic or mechanical, including photocopying and microfilm, without permission in writing from ITU. ll ITU-T Q.713 (03/2001) CONTENTS 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10 2 2.1 2.2 2.3 3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 General . Message type code Form
16、atting principles Mandatory variable part Optional part End of optional parameters octet . Order of transmission . Coding of spare bits Mandatory fixed part National message types and parameters International message types and parameters Coding of the general parts . Coding ofthe message type . Codi
17、ng of the length indicator Coding of the pointers SCCP parameters End of optional parameters . Destination local reference . Source local reference Called party address . 3.4.1 Address indicator . 3.4.2 Address: Calling party address Protocol class . Segmenting/reassembling . Receive sequence number
18、 . Sequencinghegment ing Credit . Release cause . Return cause . Reset cause . Error cause . Refusal cause Data ITU-T Q.713 (03/2001) Page 1 1 5 6 6 6 7 7 8 12 13 13 13 14 14 14 15 15 16 16 17 . 111 3.17 3.18 3.19 3.20 4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 4.1 1 4.12 4.13 4.14 4.15 4.16 4.17 4.
19、18 4.19 4.20 4.21 5 5.1 5.2 Segmentation Hop counter Importance . Long data . SCCP messages and codes General . Connection request (CR) Connection confirm (CC) . Connection refused (CREF) Released (RLSD) Release complete (RLC) . Data form 1 (DT1) Data form 2 (DT2) Data acknowledgement (AK) Unitdata
20、(UDT) Unitdata service (UDTS) Expedited data (ED) . Expedited data acknowledgement (EA) Reset request (RSR) . Reset confirmation (RSC) . Protocol data unit error (ERR) Inactivity test (IT) . Extended unitdata (XUDT) . Extended unitdata service (XUDTS) . Long unitdata (LUDT) Long unitdata service (LU
21、DTS) SCCP Management messages and codes . General . 5.1.1 SCMG format identifier . 5.1.2 Formatting principles . SCMG message parameters 5.2.1 Affected SSN . 5.2.2 Affected PC . 5.2.3 Subsystem multiplicity indicator 5.2.4 SCCP congestion level . 5.3 SCCP Messages iv ITU-T Q.713 (03/2001) Page 17 18
22、 18 18 18 18 19 19 20 20 20 21 21 21 22 22 23 23 23 23 24 24 24 25 26 26 27 27 27 27 27 27 27 27 28 28 Page 29 29 29 29 29 29 Annex A . Mapping for cause parameter values A.l Introduction A.2 Connection refusal A.3 Connection release . A.4 Connection reset . AS Return cause . Annex B . International
23、 SCCP addressing and format specification B . 1 Introduction B.2 Guidelines on using SCCP addressing information elements in the international network B.3 GT routing specification of international services . B.4 International GT routing specification B.4.1 Translation selector: T = 17, NP = 1, NAI =
24、 4 . B.4.2 Translation selector: TT = 1, NP = O, NAI = 4 . B.4.3 Translation selector: TT = 2, NP = 2, NA1 = 4 . B.4.4 Translation selector: TT = O, NP = 1, NA1 = 4 . B.4.5 Translation selector: TT = 3, NP = 1, NAI = 4 . B.4.6 Translation Selector: T = 40, NP = 6, NA1 = 4 . B.4.7 Translation Selecto
25、r: T = O, NP = 7, NA1 = 4 . 32 32 32 33 34 34 35 36 36 37 38 39 ITU-T Q.713 (03/2001) V ITU-T Recommendation 4.713 Signalling connection control part formats and codes 1 General This Recommendation specifies the SCCP messages formats and codes for the support of connection-oriented services, connect
26、ionless services and the management of SCCP. The SCCP messages are passed between SCCP and MTP across the MTP-SAP by means of the user data parameter of the MTP-TRANSFER request or indication primitives as appropriate (see Table l/Q.701). NOTE - The MTP-TRANSFER primitive, in addition to the user da
27、ta parameter, contains four parameters with the contents as follows (see Table UQ.701): o the contents of the OPC consisting of information equivalent to 14 bits, to be conveyed in the the contents of the DPC consisting of information equivalent to 14 bits, to be conveyed in the the contents of the
28、SLS consisting of information equivalent to 4 bits. If the MTP service standard routing label of the MTP; standard routing label of the MTP; “in-sequence delivery“ of SDUs is a requirement, SCCP shall use the same SLS value for all SDUs with the same sequence control and called address parameters; 0
29、01 1 binary (see 14.2.UQ.704). o o o information equivalent to the contents of the SIO. For SCCP, the encoding for the service indicator is A SCCP message consists of the following parts (see Figure 1): - the message type code; - the mandatory fixed part; - the mandatory variable part; - The descrip
30、tion of the various parts is contained in the following clauses. SCCP management messages and codes are provided in clause 5. the optional part, which may contain fixed length and variable length fields. MTP routing label I Message twe code I1 I - * II SCCP Message Mandatory fixed part Mandatory var
31、iable part I Optional part I Figure 1/Q.713 - General layout 1.1 Message type code The message type code consists of a one octet field and is mandatory for all messages. The message type code uniquely defines the function and format of each SCCP message. The allocation of message type codes, with re
32、ference to the appropriate descriptive clause of this Recommendation is summarized in Table 1. Table 1 also contains an indication of the applicability of the various message types to the relevant classes of protocol. ITU-T Q.713 (03/2001) 1 1.2 Formatting principies Each message consists of a numbe
33、r of parameters listed and described in clause 3. Each parameter has a “name“ that can be represented by a single octet (see clause 3), and is present in optional parameters. The length of a parameter may be fKed or variable, and a “length indicator“ of one octet for each parameter may be included a
34、s described below. The length indicator of the long data parameter shall be two octets, with the less significant octet preceding the transmission of the more significant octet. The detailed format is uniquely defined for each message type as described in clause 4. A general SCCP message format is s
35、hown in Figure 2. t- Order of bit transmission Order of octet 876 54 3 2 1 transmission Routing label Message type code I Mandatory parameter A I Mandatory parameter F Pointer to parameter M Length indicator of parameter P Parameter P II I Parameter name = X Length indicator of parameter X L Paramet
36、er X I I I Parameter name = Z I Length indicator of parameter Z Parameter Z I I _ End of optional parameters Figure 2/Q.713 - General SCCP message format Mandatory fixed part Mandatoq variable part Optional part T1178720-96 2 ITU-T Q.713 (03/2001) 1.3 Mandatory fixed part Those parameters that are m
37、andatory and of fixed length for a particular message type will be contained in the “mandatory fixed part“. The position, length and order of the parameters is uniquely defined by the message type. Thus the names of the parameters and the length indicators are not included in the message. 1.4 Mandat
38、ory variable part Mandatory parameters of variable length will be included in the mandatory variable part. The name of each parameter and the order in which the pointers are sent is implicit in the message type. Parameter names are, therefore, not included in the message. A pointer is used to indica
39、te the beginning of each parameter. Because of this, parameters may be sent in an order different from that of the pointers. Each pointer is encoded as a single octet or two octets in the case of LUDT and LUDTS. In the case of the two-octet pointer, the less significant octet shall be transmitted be
40、fore the more significant octet. The details of how pointers are encoded is found in 2.3. The number of parameters, and thus the number of pointers, is uniquely defined by the message type. A pointer is also included to indicate the beginning of the optional part. If the message type indicates that
41、no optional part is allowed, then this pointer will not be present. If the message type indicates that an optional part is possible, but there is no optional part included in this particular message, then a pointer field containing all zeros will be used. All the pointers are sent consecutively at t
42、he beginning of the mandatory variable part. Each parameter contains the parameter length indicator followed by the contents of the parameter. All the pointers indicating the beginning of each mandatory variable parameter and the beginning of the optional part shall ensure that at the originating no
43、de the parameters are contiguous; and “gaps“ shall not be left in between parameters in generating messages. Treatment of “gaps“ at the receiving side is specified in 1.1.4.5/Q.714. Gaps should not be generated between the last pointer and first mandatory variable parameter. No extraneous octets sho
44、uld be added after the last parameter. All the above cases will not cause a protocol error. 1.5 Optional part The optional part consists of a contiguous block of parameters that may or may not occur in any particular message type. The optional part may start after the pointer or after the mandatory
45、variable part. Both fixed length and variable length parameters may be included. Optional parameters may be transmitted in any order. Each optional parameter will include the parameter name (one octet) and the length indicator (one octet) followed by the parameter contents. 1.6 After all optional pa
46、rameters have been sent, an end of optional parameters octet containing all zeros will be transmitted. This octet is included only if optional parameters are present in the message. The end of optional parameters octet should not be used to detect the end of messages. End of optional parameters octe
47、t 1.7 Order of transmission Since all the parameters consist of an integral number of octets, the formats are presented as a stack of octets. The first octet transmitted is the one shown at the top of the stack and the last is the one at the bottom (see Figure 2). There are currently messages (RSR a
48、nd ERR) containing one pointer to the beginning of the optional part although no optional parameters are currently defined for them. ITU-T Q.713 (03/2001) 3 1.8 Coding of spare bits According to the general rules defined in ITU-T Q.700 and Q.1400, spare bits are coded O unless indicated otherwise at
49、 the originating nodes. Handling of spare fields is specified in 1.1.4.4/Q.7 14. 1.9 If message type codes and parameter codes are required for national uses, it is suggested that the codes be selected from the highest code downwards, that is starting at code 11111110. Code 1 1 11 1 11 1 is reserved for future use. National message types and parameters 1.10 Message type codes and parameter codes are required for international use. These codes are selected Fom the lowest code values upwards, i.e., starting at 00000000. Note that the special codes applicable for international use are s
