1、INTERNATIONAL TELECOMMUNICATION UN ION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU X.25 Corrigendum I (09/98) SERIES X: DATA NETWORKS AND OPEN SYSTEM COM M U N I CATI O NS Public data networks - Interfaces Interface between Data Terminal Equipment (DTE) and Data Circuit-terminating Equipme
2、nt (DCE) for terminais operating in the packet mode and connected to public data networks by dedicated circuit Corrigendum 1 ITU-T Recommendation X.25 - Corrigendum 1 (Previously CCITT Recommendation) 4862591 Ob56539 860 ITU-T X-SERIES RECOMMENDATlONS DATA NETWORKS AND OPEN SYSTEM COMMUNICATIONS PUB
3、LIC DATA NETWORKS Services and facilities Interfaces Transmission, signalling and switching Network aspects Maintenance Administrative arrangements OPEN SYSTEMS INTERCONNECTION Model and notation Service definitions Connection-mode protocol specifications Connectionless-mode protocol specifications
4、PICS proformas Protocol Identification Security Protocols Layer Managed Objects Conformance testing INTERWORKING BETWEEN NETWORKS General Satellite data transmission systems MESSAGE HANDLING SYSTEMS DIRECTORY OS1 NETWORKING AND SYSTEM ASPECTS Networking Efficiency Quality of service Naming, Addressi
5、ng and Registration Abstract Syntax Notation One (ASN.) OS1 MANAGEMENT Systems Management framework and architecture Management Communication Service and Protocol Structure of Management Information Management functions and ODMA functions SECURITY OS1 APPLICATIONS Commitment, Concurrency and Recover
6、y Transaction processing Remote operations OPEN DISTRIBUTED PROCESSING X.1-X. 19 X.20-X.49 X 50-X . 89 X.90-X. 149 X. 150-X. 179 X.180-X. 199 X .200-X . 209 x.21 o-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.349 X.350-X.399 X .400-X .499 X.5
7、00-X.599 X.600-X.629 X.630-X.639 X. 640-X. 649 X.650-X.679 X.680-X.699 X.700-X . 709 X.7 1 O-X. 7 1 9 X.720-X.729 X.730-X.799 X. 800-X. 849 X.850-X.859 X.860-X.879 X.880-X.899 X .900-X ,999 For further details, please refer fo ITU-T List ofRecornrnenduiions. 9 48b259L Ob5b540 582 = ITU-T RECOMMENDAT
8、ION X.25 INTERFACE BETWEEN DATA TERMINAL EQUIPMENT (DTE) AND DATA IN THE PACKET MODE AND CONNECTED TO PUBLIC DATA NETWORKS BY DEDICATED CIRCUIT CIRCUIT-TERMINATING EQUIPMENT (DCE) FOR TERMINALS OPERATING CORRIGENDUM 1 Source Corrigendum 1 to ITU-T Recommendation X.25 was prepared by ITU-T Study Grou
9、p 7 (i 997-2000) and was approved by Study Group 7 at its Plenary on the 25th of September 1998. Recommendation X.2YCor.l (09/98) i FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecornrnuni- cations. The ITU Telecommunication Standard
10、ization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WT
11、SC), which meets every four years, establishes 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 ITU-T is covered by the procedure laid down in WTSC Resolution No. 1. In some areas of in
12、formation technology which fail within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with IS0 and IEC. NOTE In this Recommendation the term recognized operating agency (ROA) includes any individual, company, corporation or governmental organization that operates a pub
13、lic correspondence service. The terms Administration, ROA and public correspondence are defined in the Constitution of the ITU (Geneva, 1992). INTELLECTUAL PROPERTY RIGHTS The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a c
14、laimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability 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, th
15、e ITU had not received notice of intellectual property, protected by patents, which may be required to implement 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 1999
16、 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. 11 Recommendation X.2W2or.l (09/98) CONTENTS Subclause 4.4.1.3, Window Description.
17、 4th paragraph . Table 5-21x25 . . . Subclause 6.2, Note Table 6-liX.25 . Table 6-2iX.25 Subclause 7.3. I .3, last paragraph . . . Table C.2/X.25 Page 1 1 i 2 2 Recommendation X.25Cor.l (09/98) . 111 Recommendation X.25 INTERFACE BETWEEN DATA TERMINAL EQUIPMENT (DTE) AND DATA IN THE PACKET MODE AND
18、CONNECTED TO PUBLIC DATA NETWORKS BY DEDICATED CIRCUIT CIRCUIT-TERMINATING EQUIPMENT (DCE) FOR TERMINALS OPERATING CORRIGENDUM 1 (Geneva, 1998) 1) Subclause 4.4.1.2, Window Description, 4th paragraph Change: The standard window size W is 2 for each direction of data transmission at the DTE/DCE inter
19、face. To: The standard window size W is 2 for modulo 8 and 128, and 128 for modulo 32 768, for each direction of data transmission at the DTE/DCE interface. 2) Table 5-2/X.25 Delete: DCE REJ (modulo 32 768)a) 3) Subclause 5.6.2 Change: To: Change. To: When the diagnostic packet is issued as a result
20、 of the reception of an erroneous packet from the DTE (see Tables C. 1 and C2), this field contains the first three octets of header information from the erroneous DTE packet. If the packet contains less than 3 octets, this field contains whatever bits were received. When the diagnostic packet is is
21、sued as a result of the reception of an erroneous packet from the DTE (see Tables C. 1 and C.2), this field contains the first three octets of header information from the erroneous DTE packet for modulo 8 and 128 operation and the first four octets of header information from the erroneous DTE packet
22、 for modulo 32 768 operation. If the packet contains less than 3 octets for modulo 8 and 128 operation and less than 4 octets for modulo 32768 operation, this field contains whatever bits were received. When the diagnostic packet is issued as a result of a DCE time-out (see Table D.l), the diagnosti
23、c explanation field contains 2 octets coded as follows: - bits 8,7, 6 and 5 of the first octet contain the general format identifier for the interface; - bits 4 to 1 of the first octet and bits 8 to 1 of the second octet are all O for expiration of time-out T10 and give the number of the logical cha
24、nnel on which the time-out occurred for expiration of time-out T12 or T13. When the diagnostic packet is issued as a result of a DCE time-out (see Table D.l), the diagnostic explanation field contains 2 octets for modulo 8 and 128 operation, coded as follows: - bits 8, 7, 6 and 5 of the first octet
25、contain the general format identifier for the interface; - bits 4 to 1 of the first octet and bits 8 to 1 of the second octet are all O for expiration of time-out T10 and give the number of the logical channel on which the time-out occurred for expiration of time-out T12 or T13. Recommendation X.251
26、Cor.l (09/98) 1 H 4862591 Ob56544 128 = W(indicated) 2 2 W(indicated) = i P(indicated) 2 I28 P(indicated) 128 When the diagnostic packet is issued as a result of a DCE time-out (see Table D.l), the diagnostic explanation field contains 3 octets for modulo 33 768 operation, coded as follows: W(indica
27、ted) 1 W(requested) 2 2 W(requested) = 1 or 2 P(indicated) 2 P(requested) 2 128 128 1 P(requested) 2 P(indicated) - bits 8, 7, 6 and 5 of the second octet contain the general format identifier for the interface; 8 and 128 32 768 - bits 4 to 1 of the second octet and bits 8 to 1 of the third octet ar
28、e all O for expiration of time-out T1 O and give the number of the logical channel on which the time-out occurred for expiration of time-out T12 or T13. W(indicated) 1 2 W(indicated) = i W(indicated) 2 I28 W(indicated) 5 128 W(indicated) 2 W(requested) 1 2 W(requested) = 1 or2 W(indicated) 2 W(reque
29、sted) 2 128 W(indicated) I W(requested) I 128 4) Subclause 6.2, Note Any modulo is applicable Change: NOTE - In addition, some networks may permit the DTE to choose to use modulo 32 768 or modulo 128 or modulo 8 on a per-virtual call or logical channel basis. In this case, the use of either modulo 8
30、 or modulo 128 or modulo 32 768 is permitted at the same DTEDCE interface, with dynamic selection by the calling DTE. The same modulo applies to both directions of transmission. The means for the network to select the modulo in the incoming call packet for a given call is beyond the scope of this Re
31、commendation. P(indicated) 2 128 P(indicated) 128 P(indicated) 2 P(requested) 2 128 128 2 P(requested) 2 P(indicated) To: NOTE - In addition, some networks may permit the DTE to choose to use modulo 32 768 or modulo 128 or modulo 8 on a per-viriual call or logical channel basis. In this case, the us
32、e of either modulo 8 or modulo 128 or modulo 32 768 is permitted at the same DTEDCE interface, with dynamic selection by the calling DTE. The same modulo applies to both directions of transmission. The means for the network to select the modulo in the incoming call packet for a given call is beyond
33、the scope of this Recommendation. For restarf and diagnostic packets, any valid format can be used in this case. 5) Table 6-UX.25 Change: Table 6-1/X.25 - Valid facility request in call accepted packets in response to facility indications in incoming call packets I Faciliy indication I Valid faciliy
34、 request I Table 6-UX.25 - Valid facility request in call accepted packets in response to facility indications in incoming call packets Modulo Facility indication Valid facility request I I I 3 Recommendation X.25Kor.l (09/98) 6) Table 6-2/X.25 Change: W(requested) t 2 W(requested) = 1 P(requested)
35、2 128 P(requested) 128 Table 6-2/X.25 - Valid facility requests in call accepted packets in response to facility indication in incoming call packets W(requested) 2 W(indicated) 2 2 W(indicated) = 1 or 2 P(requested) 2 P(indicated) 2 128 128 L P(indicated) 2 P(requested) r Modulo 8 and 128 32 768 Any
36、 modulo is applicable Facility request Facility request Valid facility request W(requested) 2 2 W(requested) = 1 W(requested) 2 128 W(requested) I 128 P(requested) 2 128 P(requested) 128 W(requested) 2 W(indicated) 2 2 W(indicated) = 1 or 2 W(requested) 2 W(indicated) L 128 W(requested) I W(indicate
37、d) I I28 P(requested) 2 P(indicated) 2 128 128 2 P(indicated) 2 P(requested) Valid facility request To: 7) Subclause 7.3.1.3, last paragraph Change: To: Window sizes of 128 to 32 768 are only valid if super extended sequence numbering is used (see 6.3). Window sizes of 128 to 32 767 are only valid i
38、f super extended sequence numbering is used (see 6.3). 8) Table C.2/X.25 Change: Restart request or DTE restart confirmation with bits 1 to 4 of octet 1 or bits 1 to 8 of octet 2 unequal to zero Restart request or DTE restart confirmation with bits 1 to 4 of the octet containing the GFI and bits 1 t
39、o 8 of the following octet unequal to zero To: Recommendation X.2WZor.l (09/98) 3 - 4862591 Ob5b5Yb TTO = ITU-T RECOMMENDATIONS SERIES Series A Series B Series C Series D Series E Series F Series G Series H Series I Series J Series K Series L Series M Series N Series O Series P Series Q Series R Ser
40、ies S Series T Series U Series V Series X Series Y Series Z Organization of the work of the ITU-T Means of expression: definitions, symbols, classification General telecommunication statistics General tariff principles Overall network operation, telephone service, service operation and human factors
41、 Non-telephone telecommunication services Transmission systems and media, digital systems and networks Audiovisual and multimedia systems Integrated services digital network Transmission of television, sound programme and other multimedia signals Protection against interference Construction, install
42、ation and protection of cables and other elements of outside plant TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits Maintenance: international sound programme and television transmission circuits Specifications of measurin
43、g equipment Telephone transmission quality, telephone installations, local line networks Switching and signalling Telegraph transmission Telegraph services terminal equipment Terminals for telematic services Telegraph switching Data communication over the telephone network Data networks and open system communications Global information infrastructure Programming languages Printed in Switzerland Geneva, 1999
