1、 ITU-T RECMN+X.214 95 W 4862573 Ob32674 584 m INTERNATIONAL TELECOMMU N CATION UN ION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU X.214 (1 1/95) DATA NETWORKS AND OPEN SYSTEM COMMUNICATIONS SERVICE DEFINITIONS OPEN SYSTEMS INTERCONNECTION - INFORMATION TECHNOLOGY - OPEN SYSTEMS INTERCONNEC
2、TION - TRANSPORT SERVICE DEFINITION ITU-T Recommendation X.214 (Previously “CCITT Recommendation“) ITU-T RECMN*X-214 75 4Ab2591 0b12b75 410 FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Stan
3、dardization Sector (ITU-T) is a permanent organ of the ITU. Some 179 member countries, 84 telecom operating entities, 145 scientific and industrial organizations and 38 international organizations participate in iTU-T which is the body which sets world telecommunications standards (Recommendations).
4、 The approval of Recommendations by the Members of ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, 1993). In addition, the World Telecommunication Standardization Conference (WTSC), which meets every four years, approves Recommendations submitted to it and establishes
5、 the study programme for the following period. In some areas of information technology which fall within IT-Ts purview, the necessary standards are prepared on a collaborative basis with IS0 and IEC. The text of ITU-T Recommendation X.214 was approved on 21st of November 1995. The identical text is
6、also published as ISOLEC International Standard 8072. NOTE In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. O ITU 1996 All rights reserved. No part of this publication may be reprodu
7、ced or utilized in any form or by any means, electronic or I mechanical, including photocopying and microfilm, without permission in writing from the ITU. ITU-T X-SERIES RECOMMENDATIONS DATA NETWORKS AND OPEN SYSTEM COMMUNICATIONS Subject area PUBLIC DATA NETWORKS (February 1994) ORGANIZATION OF X-S
8、ERIES RECOMMENDATIONS Recommendation Series Services and Facilities Interfaces X. 1-X. 19 X.20-X.49 I Transmission, Signalling and Switching I X.50-X.89 I Network Aspects Maintenance X.90-X.149 X. 150-X. 179 Administrative Arrangements OPEN SYSTEMS INTERCONNECTION Model and Notation X.180-X.199 X .2
9、00-X . 209 Service Definitions Connection-mode Protocol Specifications I Protocol Identification I X.260-X.269 I X.2 10-X.2 19 X.220-X.229 Connectionless-mode Protocol Specifications PICS Proformas X.230-X.239 X.240-X.259 Security Protocols Layer Managed Objects I Management I X.370-X.399 I X.270-X.
10、279 X.280-X.289 Conformance Testing INTERWORKING BETWEEN NETWORKS 1 OS1 NETWORKING AND SYSTEM ASPECTS -1 I X.290-X.299 General Mobile Data Transmission Systems X.300-X.349 X.350-X.369 MESSAGE HANDLING SYSTEMS DIRECTORY X.400-X.499 X.500-X.599 _ Networking Naming, Addressing and Registration X. 600-X
11、. 649 X.650-X.679 Abstract Syntax Notation One (ASN. 1) OS1 MANAGEMENT X.680-X.699 x.700-x.799 SECURITY OS1 APPLICATIONS X.800-X.849 Commitment, Concurrency and Recovery X. 850-X. 859 Transaction Processing Remote Operations OPEN DISTRIBUTED PROCESSING X.860-X.879 X.880-X.899 X.900-X.999 ITU-T RECMN
12、*X-214 95 4862591 Ob32677 293 CONTENTS SECTION 1 . GENERAL 1 Scope 2 Normative references . 2.1 Identical Recommendations I International Standards 3 Definitions 3.1 Reference Model definitions . 3.2 Service (Definition) conventions 3.3 Transport Service Definitions . 4 Abbreviations . 5 Conventions
13、 5.1 General conventions 5.2 Parameters . Overview and general characteristics . Classes and types of Transport Service 6 7 SECTION 2 - DEFINITION OF THE CONNECTION-MODE SERVICE . 8 9 10 11 12 Features of the connection-mode Transport Service Model of the connection-mode Transport Service . 9.1 Gene
14、ral 9.2 Model of a Transport Connection . Quality of connection-mode Transport Service . 1 O . 1 10.2 10.4 Transit delay 10.5 Residual error rate . 10.7 TC release delay 10.8 TC establishment delay . TC establishment failure probability . 10.3 Throughput 10.6 Transfer failure probability . TC releas
15、e failure probability . 10.9 TC protection 10.10 TC priority 1 O . 1 1 Resilience of the TC . Sequence of Transport Service primitives Relation of TS primitives at the two TC endpoints . 11.1 11.2 Sequence of TS primitives at one TC endpoint Transport Connection establishment phase 12.1 Function 12.
16、2 12.2.1 Addresses 12.2.2 Called Address 12.2.3 Calling Address . 12.2.4 Responding Address . 12.2.5 Expedited Data option . 12.2.6 Quality of Service . 12.2.7 TS user-data Sequence of TS primitives Types of TS primitives and parameters 12.3 12.4 Negotiation of expedited data transfer service Page 1
17、 1 1 1 2 2 2 2 3 3 3 3 3 4 4 4 5 5 5 7 8 8 8 9 9 9 10 10 10 10 10 11 11 11 14 14 14 14 14 15 15 15 15 16 16 16 ITU-T Rec . X.214 (1995 E) 1 13 Data transfer phase . 13.1 Data Transfer Service . 13.1.1 Function 13.1.2 Types of TS primitives and parameters 13.1.2.1 TS user-data 13.1.3 Sequence of TS p
18、rimitives Expedited data transfer service . 13.2.1 Function 13.2.2 Types of TS primitives and parameters 13.2.2.1 TS userdata 13.2.3 Transport Connection release phase . 14.1 Function 14.2 Types of TS primitives and parameters 14.2.1 Reason . 14.2.2 TS user-data Sequence of TS primitives in TS user
19、rejection of a TC establishment 13.2 Sequence of TS primitives 14 14.3 14.4 14.5 Sequence of TS primitives when releasing an established transport connection Sequence of TS primitives in a TS provider rejection of a TC Establishment attempt . SECTION 3 - DEFINITION OF THE CON“IONLESS-MODE SERVICE 15
20、 16 17 18 19 Features of the connectionless-mode Transport Service Model of the connectionless-mode Transport Service . Model of transport connectionless-mode transmission . 16.1 General 16.2 Quality of connectionless-mode Transport Service . 17.1 Determination of QOS 17.2 Definition of connectionle
21、ss-mode QOS parameters 17.2.1 Transit delay 17.2.2 Protection 17.2.3 Residual error probability . Sequence of connectionless-mode primitives at one TSAP . Data transfer . 19.1 Function 19.2 Types of primitives and parameters 19.2.1 Addresses 19.2.2 Quality of Service . 19.2.3 TS user data . 19.3 Seq
22、uence of primitives . 17.2.4 Priority Page 17 17 17 17 17 17 17 17 18 18 18 18 18 19 19 19 19 21 21 21 21 22 22 22 23 23 23 23 24 24 24 24 25 25 25 25 25 26 26 II ITU-T RW . X.214 (1995 E) ITU-T RECMN*Xl214 75 4862591 0632679 066 Summary This Recommendation I International Standard defines the servi
23、ce provided by the transport layer to the session layer at the boundary between the transport and session layers of the OS1 reference model, which includes: a) b) c) the primitive actions and events of the service; the parameter data associated with each primitive action and event; and the relations
24、hip between, and the valid sequence of, these actions and events. Introduction This Recommendation I International Standard is one of a set of Recommendations I International Standards produced to facilitate the interconnection of computer systems. It is related to other Recommendations I Internatio
25、nal Standards in the set as defined by the Reference Model of Open Systems Interconnection (OSI). The OS1 Reference Model (see IT-T Rec. X.200 I ISO/IEC 7498-1) subdivides the area of standardization for interconnection into a series of layers of specification, each of manageable size. This Recommen
26、dation I International Standard defines the Service provided by the Transport Layer to the Session Layer at the boundary between the Transport and Session Layers of the Reference Model. It provides for the designers of Session Protocols a definition of the Transport Service existing to support the S
27、ession Protocol and for designers of Transport Protocols a definition of the services to be made available through the action of the Transport Protocol over the underlying service. This relationship is illustrated in Figure Intro. 1. Session Protocol session Transport service Provider f service U TI
28、SO(XL9(19Za)I Figure Intro. 1 - Relationship of the Transport Service to OS1 Transport and Session Protocols Throughout the set of OS1 Recommendations I International Standards, the term “Service” refers to the abstract capability provided by one layer of the OS1 Reference Model to the layer above i
29、t. Thus, the Transport Service defined in this Recommendation I International Standard is a conceptual architectural Service, independent of administrative divisions. NOTE - It is important to distinguish the specialized use of the term “Service” within the set of OS1 Recommendations I International
30、 Standards from its use elsewhere to describe the provision of a service by an organization (such as the provision of a service, as defined in other Recommendations, by an Administration). ITU-T Rec. X.214 (1995 E) iii ITU-T RECMN*X-224 95 4862592 Ob22b8O 888 = ITU-T RECMN*X=214 95 W 4862571 Ob12681
31、 714 ISO/IEC 8072 : 1996 (E) INTERNATIONAL STANDARD ITU-T RECOMMENDATION INFORMATION TECHNOLOGY - OPEN SYSTEMS INTERCONNECTION - TRANSPORT SERVICE DEFINITION SECTION 1 - GENERAL 1 Scope This Recommendation I International Standard defines in an abstract way the externally visible service provided by
32、 the OS1 Transport Layer in terms of a) the primitive actions and events of the service; b) c) the parameter data associated with each primitive action and event; the relationship between, and the valid sequences of, these actions and events. The service defined in this Recommendation I Internationa
33、l Standard is that which is provided by all OS1 Transport Protocols (in conjunction with the Network Service) and which may be used by any OS1 Session Protocol. This Recommendation I International Standard does not specify individual implementations or products, nor does it constrain the implementat
34、ion of entities and interfaces within a system. Conformance of equipment to this Recommendation I International Standard is achieved by conformance to the protocols specified to fulfil the Transport Service defined in this Recommendation i International Standard. 2 Normative references The following
35、 Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation I International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision and p
36、arties to agreements based on this Recommendation I International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and International Standards listed below. Members of IEC and IS0 maintain registers of currently valid International Sta
37、ndards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations. 2.1 Identical Recommendations I Internationai Standards - ITU-T Recommendation X.200 (1994) I ISO/IEC 7498-1:1994, Information technology - Open Systems Interconnection - Basic
38、Reference Model: The Basic Model. - ITU-T Recommendation X.210 (1993) I ISOAEC 10731:1994, Information technology - Open Systems Interconnection - Basic Reference Model: Conventions for the definition of OSI services. ITU-T Rec. X.214 (1995 E) 1 ISOAEC 8072 : 1996 (E) 3 Definitions For the purposes
39、of this Recommendation I International Standard, the following definitions apply. 3.1 Reference Model definitions This Service Definition is based on the concepts developed in the OS1 Reference Model (see ITWT Rec. X.200 I ISOhEC 7498-l), and makes use of the following terms defined in it: expedited
40、 transport-service-data-unit; transport-connection; transport-connection endpoint; Transport Layer; Transport Service; transport-service-access-point ; transport-service-access-point address; transport-service-data-unit; Network Layer; Network Service; network-connection; interface flow control. 3.2
41、 Service (Definition) conventions This Service Definition also makes use of the following terms defined in ITU-T Rec. X.210 I ISO/IEC 10731, as they apply to the Transport Layer: a) service-user; b) service-provider: c) primitive; d) request; e) indication; f) response; g) confirm. 3.3 Transport Ser
42、vice Definitions For the purpose of this Service Definition, the following definitions also apply. 3.3.1 transport connection: An association established by a Transport Layer between two TS users for the transfer of data, which provides explicit identification of a set of transport data transmission
43、s and agreement concerning the services to be provided for the set. NOTE -This definition clarifies that given in ITU-T Rec. X.200 I IS0 7498-1. calling TS user: A Transport Service user that initiates a transport connection establishment request. called TS user: A Transport Service user with whom a
44、 calling TS user wishes to establish a transport NOTE - Calling TS users and called TS users are defined with respect to a single connection. A Transport Service user can 3.3.2 3.3.3 connection. be both a calling and a called TS user simultaneously. 3.3.4 TSAP within the context of a TC that has pre
45、viously been established. I transport connectionmode data transmission: The transfer of a TSDU from a source TSAP to a destination 2 ITU-T Rec. X.214 (1995 E) ITU-T RECMNJX.214 95 4862593 0632683 597 ISO/IEC 8072 : 1996 (E) 3.3.5 transport connectionless-mode data transmission: The transmission of a
46、 TSDU from a source TSAP to one or more destination TSAPs outside the context of a TC and without any requirement to maintain any logical relationship among multiple TSDUs. 3.3.6 transport-connection, or during a particular instance of transport connectionless-mode data transmission. 3.3.7 transport
47、-connection, or during a particular instance of transport connectionless-mode data transmission. sending TS user: A Transport Service user that acts as a source of data during the data transfer phase of a receiving TS user: A Transport Service user that acts as a sink of data during the data transfe
48、r phase of a NOTE - A Transport Service user can be both a sending and a receiving TS user simultaneously. group transport address: An address that identifies a particular group of TSAPs. A group Transport address 3.3.8 may only be used to identify destination addresses. 4 Abbreviations For the purp
49、oses of this Recommendation I International Standard, the following abbreviations apply: TS Transport Service TC Transport-connection TSAP Transport-service-access-point TSDU Transport-service-data-unit QOS Quality of Service 5 Conventions 5.1 General conventions This Service Definition uses the descriptive conventions given in ITU-T Rec. X.210 I ISOAEC 1073 1. 5.2 Parameters The available parameters for each group of primitives are set out in tables in clauses 12 to 14 and 19. Each “X in the tables indicates that the primitive labelling the column in which it falls may car
