1、STD-ITU-T RECMN X-5-ENGL L77b qb2571 Ob22371 TZ0 INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU x.5 (1 0/96) SERIES X: DATA NETWORKS AND OPEN SYSTEM COM M U N I CATI ON Public data networks - Services and facilities Facsimile Packet AssemblylDisacsembly f
2、acility (FPAD) in a public data network ITU-T Recommendation X.5 (Previously CCITT Recommendation,) STD-ITU-T RECMN X*S-ENGL L77b qBb257L 0b2.2372 Yb7 D ITU-T X-SERIES RECOMMENDATIONS DATA NETWORKS AND OPEN SYSTEM COMMUNICATION Interfaces X.20-X.49 Transmission, signalling and switching X.50-X.89 Ne
3、twork aspects Maintenance Administrative arrangements Model and notation Service definitions Connection-mode protocol specifications Connectionless-mode protocol specification PICS proformas Protocol Identification Security Protocols Layer Managed Objects Conformance testing General Satellite data t
4、ransmission networks OPEN SYSTEM INTERCONNECTION INTERWORKING BETWEEN NETWORKS MESSAGE HANDLING SYSTEMS DIRECTORY OS1 NETWORKING AND SYSTEM ASPECTS Networking Efficiency Naming, Addressing and Registration Abstract Syntax Notation One (ASN.l) Systems Management framework and architecture Management
5、Communication Service and Protocol Structure of Management Information Management functions OS1 MANAGEMENT SECURITY OS1 APPLICATIONS Commitment, Concurrency and Recovery Transaction processing Remote operations OPEN DISTRIBUTED PROCESSING X.90-X.149 X.150-X. 179 X.180-X.199 X.200-X.299 X.200-X .209
6、X.2 10-X.219 X.220-X.229 X.230-X.239 X.240-X.259 X.260-X.269 X.270-X.279 X.280-X.289 X.290-X.299 X.300-X. 399 X .300-X. 349 X.350-X.399 x.400-x.499 X.500-X.599 X.600-X.699 X.600-X.629 X.630-X.649 X.650-X.679 X.680-X.699 x.700-x.799 X.700-X.709 X.710-X.719 X.720-X.729 X.730-X.799 X.800-X.849 X.850-X.
7、899 X.850-X.859 X.860-X.879 X.880-X. 899 X.900-X.999 II For further details, please refer to ITU-T List of Recommendations. STDSITU-T RECMN X.5-ENGL L77b i8b257L Ob22373 8T3 = FOREWORD The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Un
8、ion (IT). The -T is responsible for studying technical, operating and tariff questions and issuing Recommenda- tions on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes
9、the topics for study by the ITU-T Study Groups which. in their turn, produce Recommendations on these topics. The approval of Recommendations by the Members of the IT-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993). -T Recommendation X.5 was revised by I
10、TU-T Study Group 7 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 5th of October 1996. 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
11、 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. I Recommendation X.5 (10196) STD-ITU-T RECMN X.5-ENGL 17b m 48b25L b22374 73T = CON
12、TENTS Preface . 1 Introduction 1.1 scope 1.2 Physical configurations . 1.2.1 G3 facsimile equipmen/FPAD . 1.2.2 Operating environments G3 facsimile equipment requirements . Requirements of an application DTE Configuration of the WAD by the G3 facsimile equipment 2.2 WAD parameters 1.3 Requirements 1
13、.3.1 1.3.2 2 Description of the basic functions and user selectable functions ofthe FPAD 2.1 2.3 Functions of the FPAD . 2.3.1 Basic functions 2.3.2 Optional functions . 2.4 Facsimile characteristics of the WAD 2.5 User selectable functions which may be provided by the FPAD 2.5.1 Control of FPAD ser
14、vice signals Characteristics of FPAD parameters 3.1 Characteristics of parameters 3.2 Possible values of parameters . 3.3 Relationship with Recommendations X.38 and X.39 . 3.4 Determination of the values of FPAD parameters Initial values of PAD parameters List of FPAD parameters and possible values
15、3 3.4.1 3.4.2 Current values of WAD parameters . Control of FPAD service signals Annex A - Alphabetical list of abbreviations used in this Recommendation . Annex B - Access to MHS B . 1 Introduction B.2 References B.3 Terms and definitions . B.4 Abbreviations B.5 Conventions B.6 Functional model B.6
16、.1 Functional model for access of a G3FE to MHS via FPAD . B.6.2 Networks and protocols involved . 3.6.3 MHS elements of service for G3FE access to MHS via FPAD B.6.4 MHS operations 4 4.1 Page 1 1 2 2 2 3 4 4 4 4 4 4 5 5 5 5 5 6 6 6 6 7 7 7 7 7 7 8 8 8 8 9 9 9 9 9 10 10 11 II Recommendation X.5 (10/
17、96) STD-ITU-T RECMN X-5-ENGL L99b LiAb257L Ob22375 b7b Recommendation X.5 FACSIMILE PACKET ASSEMBLY/DISASSEMBLY FACILITY (FPAD) IN A PUBLIC DATA NETWORK (revised in 1992) Preface The establishment in various countries of public data networks providing packet switched data transmission services creat
18、es a need to produce standards to facilitate G3 facsimile equipment access from the public telephone network. The ITU-T, considering (a) that Recommendations X.l and X.2 define the user classes of service and user facilities in public data networks, Recommendation X.96 defines call progress signals.
19、 Recommendation X.39 defines the procedures between a Facsimile Packet Assembly/Disassembly facility (FPAD) and a packet mode DTE or another FPAD, Recommenda- tion X.38 defines the G3 facsimile equipment/DCE interface for a facsimile equipment accessing the FPAD; (b) X.92, and that in particular Rec
20、ommendation X.92 allows for incorporation of a PAD; that the logical control links for packet switched data transmission services are defined in Recommendation (cl that G3 facsimile or associated equipments will send and receive network control information and user information in the form of dual-to
21、ne multi-frequency codes defined in Recommendation 4.23 or signals defined in Recommendations T.4 and T.30; (d) information in the form of packets in accordance with Recommendation X.25; that DTEs operating in the packet mode will send and receive network control information and user (e) packet mode
22、 DTEs may wish to control specific functions of the PAD, that the packet mode DTE shall not be obliged to use the control procedures for WAD functions, but that some unanimously declares (I) are described below in clause 2; that the functions performed by, and operational characteristics of, the FPA
23、D for the G3 facsimile equipment (2) variables known as WAD parameters which are described in clause 3; that the operation of FPAD for the G3 facsimile equipment should depend on the possible values of internal (3) in clause 4. that the WAD parameters for the G3 facsimile equipment and their possibl
24、e values are listed below 1 Introduction An FPAD is a facility which offers a G3 facsimile equipment the opportunity to use a public data network to convey facsimile control and image data to another G3 facsimile equipment or to an application DE. The WAD also allows an application DTE to establish
25、a connection and to send control and image data to a G3 facsimile equipment. It is an underlying principle of the WAD environment that to the degree possible, the performance and quality of the service of the two G3 facsimile equipments as available today utilizing the general switched telephone net
26、work are not negatively affected. Recommendation X.5 (10/96) 1 STD-ITU-T RECMN X-5-ENGL 197b 48b2571 Ob2237b 502 NOTE-The term G3 facsimile equipment used here is slightly different from the T-Series Recommendations. In this Recommendation it is taken to be a G3 facsimile equipment which conforms to
27、 Recommendation T.41T.30, along with the necessary ancillary control device as described in 2.1.1K.38. 1.1 Scope Support for the following cases is provided in the WAD Series of Recommendations: a) A G3 facsimile equipment to a G3 facsimile equipment - A G3 facsimile equipment establishes a call to
28、a G3 facsimile equipment, dialling in one or two stages the number of the called G3 facsimile equipment: - the calling G3 facsimile equipment transmits document(s) to the called G3 facsimile equipment; - the called G3 facsimile equipment transmits document(s) to the calling G3 facsimile equipment. A
29、 G3 facsimile equipment to an application DTE - A G3 facsimile equipment establishes a call to an application DTE, dialling in one or two stages the number of the called application DE: - - An application DTE calling to a G3 facsimile equipment - An application DTE establishes a call to a G3 facsimi
30、le equipment: - - b) the calling G3 facsimile equipment transmits document(s) to the called application DTE; the called application DTE transmits document(s) to the calling G3 facsimile equipment. c) the calling application equipment transmits document(s) to the called G3 facsimile; the called G3 fa
31、csimile equipment transmits document(s) to the calling application DTE. NOTE - Additional cases are for further study. 1.2 Physical configurations 1.2.1 G3 facsimile equipmenWPAD Two models are defined for the connection of a G3 facsimile equipment and an WAD. These two models are illustrated in Fig
32、ure 1. G3 facsimile FPAD equipment a) G3 facsimile equipmenffFPAD comected via the general switched telephona network FPAD G3 facsimile equipnent b) 63 facsimile equipmenffFPAD connected brealy TO7081 M)-SCYdOl 2 FIGURE 1m.5 Recommendation X.5 (10/96) STD-ITU-T RECMN X-5-ENGL L77b 48b2571 b22377 447
33、 - 1.2.2 Operating environments Three scenarios are defined in which two G3 facsimile equipments or a G3 facsimile equipment and an application DTE may operate. These scenarios are illustrated in Figure 2. Remote Called G3 FPAD (Note 2) facsimile (Note 1) equipment equipment a) G3 facsimile equipmen
34、t to 63 facsimile equipment Called facsimile (Note 2) FPAD (Note 1) application Calling G3 equipment (remote DTE) b) 63 facsimile equipment to application DTE NOTES 1 The FPAD and the PSPDN are shown as separate elements. This is for clarity only and should not imply that the FPAD is not, or could n
35、ot be, an integral part of the PSPDN. 2 The G3 facsimile equipment and the FPAD are shown connected by the general switched telephone network. in each case, the G3 facsimile equipment and FPAD may be directly connected. 3 In this figure and throughout the FFAD Series of Recommendations, “local WAD”
36、or “local DTE” is the FPAD or DTE associated with the “calling” G3 facsimile equipment or application DTE. Similarly, “remote WAD” or “remote DTE is associated with the “called” G3 facsimile equipment or application DE. 4 The scenarios in this figure do not preclude the use of a single PAD as a loca
37、l or remote WAD on a call-by-call basis. FIGURE 2K.5 Recommendation X.5 (10/96) 3 - - 1.3 Requirements 1.3.1 G3 facsimile equipment requirements For a G3 facsimile equipment to operate in the context of an FPAD. the facsimile equipment must: - - support all mandatory standard capabilities defined in
38、 Recommendation T.4; and operate according to the procedures defined in Recommendation T.30. For the facsimile equipment to operate in the two-stage dialling mode, the facsimile equipment must provide a signalling method as defined in 2.1m.38. The facsimile equipment may: - - - NOTES 1 request any o
39、ptional standard capability defined in Recommendations T.4 and T.30 (see Note 1); request any non-standard capability; and operate manually or automatically (see Note 2). Subclause 2.4 defines the optional standard Capabilities that must be supported by an WAD. If a G3 facsimile equipment requests o
40、ne of these optional standard capabilities, the FPAD will relay the request for the optional standard capability unchanged. Similarly, if the G3 facsimile equipment requests an optional standard capability which is supported by the FPAD as an option (e.g. error correction mode), the FPAD will relay
41、the request unchanged. If the G3 facsimile equipment requests an optional standard capability (or value of such capability) which is not supported by the FPAD, the FPAD will alter the coding of the request by: - - 2 replacing the Capability value with the highest values available in the FPAD; or “tu
42、rning off the request when no alternative value is available (e.g. error correction mode). Certain restrictions may apply in the case of a facsimile equipment operating automatically as the calling station. Refer to Recommendation X.38. 1.3.2 Requirements of an application DTE For an application DTE
43、 (either calling or called) to participate in the WAD environment, it must emulate the public data interface of an FPAD as defined in Recommendation X.39. An application DTE may: - - set andor read the FPAD parameters of an FPAD; enter into an interactive dialogue as defined in Recommendation X.38.
44、2 Description of the basic functions and user selectable functions of the FPAD 2.1 Configuration of the FPAD by the G3 facsimile equipment The WAD performs a number of functions and exhibits operational characteristics. Some of the functions allow either or both the G3 facsimile equipment and the ap
45、plication DTE (or remote WAD) to configure the FPAD so that its operation is adapted to the application. 2.2 FPAD parameters The operation of FPAD depends on the values of the set of internai variables called FPAD parameters. This set of parameters exists for each G3 facsimile equipment independentl
46、y. The current value of each FPAD parameter defines the operational characteristics of its related functions. NOTE -The use of the plural in reference to FPAD parameters implies the existence of more than one parameter. However, only one FPAD parameter has so far been defined. The use of the plural
47、has been continued throughout this and the other Recommendations of the Series as an indication that other FPAD parameters are for further study. 4 Recommendation X.5 (10/96) 2.3 Functions of the FPAD 2.3.1 Basic functions Basic functions include: - - - - generation of service signais; - - - assembl
48、y of facsimile image data into packets; disassembly of the user data fields of packets; handling of virtual call Set-up and call clearing; a mechanism for forwarding packets when the proper conditions exist, e.g. when a packet is full; a mechanism for transmitting facsimile image data to G3 facsimil
49、e equipments; and a mechanism for setting the current value of WAD parameters. 2.3.2 Optional functions Optional functions (e.g. for profile selection), are for further study. 2.4 Facsimile characteristics of the FPAD The RAD will support all mandatory standard capabilities of a G3 facsimile equipment as defined in Recommenda- tion T.4. The WAD will also support the following optional standard capabilities as defined in Recommendations T.4 and T.30: a) data signalling rate - - 7200 bit/s as per Recommendation V.29; 9600 biVs as per Recommendation V.29; b) vertic
