1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU x.222 Amendment I (1 0/96) SERIES X: DATA NETWORKS AND OPEN SYSTEM COM M U N I CATI O N Open System Interconnection - Connection-mode pro toco1 specifications Use of X.25 LAPB-compatible data link procedures
2、to provide the OS1 connection-mode data link service Amendment I : Frame relay mapping ITU-T Recommendation X.222 - Amendment 1 (Previously CCITT Recommendation) ITU-T X-SERIES RECOMMENDATIONS DATA NETWORKS AND OPEN SYSTEM COMMUNICATION PUBLIC DATA NETWORKS Services and facilities Interfaces Transmi
3、ssion, signalling and switching Network aspects Maintenance Administrative arrangements OPEN SYSTEM INTERCONNECTION 1 Model and notation X.l-X.199 X.l-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.299 X.200-X.209 II Service definitions X.210-X.219 1. , h %. , I . . I. II Connec
4、tionless-mode protocol specifications X.230-X.239 PICS proformas Protocol Identification Security Protocols Layer Managed Objects Conformance testing General Satellite data transmission systems MESSAGE HANDLING SYSTEMS DIRECTORY OS1 NETWORKING AND SYSTEM ASPECTS INTERWORKING BETWEEN NETWORKS Network
5、ing Efficiency Naming, Addressing and Registration Abstract Syntax Notation One (ASN.l) Systems Management framework and architecture Management Communication Service and Protocol Structure of Management Information Management functions OS1 MANAGEMENT SECURITY OS1 APPLICATIONS Commitment, Concurrenc
6、y and Recovery Transaction processing Remote operations OPEN DISTRIBUTED PROCESSING 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
7、X.720-X.729 X.730-X.799 X.800-X.849 X.850-X.899 X.850-X.859 X.860-X.879 X.880-X.899 x.900-x.999 For further details, please refe to ITU-T List of Recommendations. FOREWORD The IT-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (IT). The
8、IT-T is responsible for studying technical, operating and tariff questions and issuing Recommen- dations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics f
9、or 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). Amendment 1 to IT-T Recommendation X.222 was prepa
10、red by IT-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 I
11、TU 1997 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. Recommendation X.222Arnd.l (10/96) 1 STD-ITU-T RECMN X-222 AMD 1-ENGL 177b E
12、 qBb2571 Ob3L4V2 O11 SUMMARY Recommendation X.222 defines a method for providing the OS1 Connection-mode Data Link Service (CO-DLS) specifying the detailed mapping between the CO-DLS and X.25/LAPB-compatible, DTE single link procedures as described in Recommendation X.25 and between detailed mapping
13、s between CO-DLS and the LAPF procedures described in Recommendation 4.922 in frame relay environments. 11 Recommendation X.222lAmd.l (10/96) Amendment 1 to Recommendation X.222 USE OF X.25 LAPB-COMPATIBLE DATA LINK PROCEDURES TO PROVIDE THE OS1 CONNECTION-MODE DATA LINK SERVICE (Former title 1995)
14、AMENDMENT 1 Frame relay mapping (Geneva, 1996) I Replace the title of Recommendation X222 (1995) with the following: 1) USE OF X.25 LAPB-COMPATIBLE DATA LINK PROCEDURES OR PROCEDURES DEFINED IN RECOMMENDATION Q.222 TO PROVIDE THE OS1 CONNECTION-MODE DATA LINK SERVICE 2) Clause 1, replace the two par
15、agraphs with the following: This Recommendation defines a method for providing the OS1 Connection-mode Data Link Service (CO-DLS) through the use of the X.25 LAPB-compatible DTE data link procedures as described in Recommendations X.25 (abbreviated to X.25/LAPB, for the remainder of this Recommendat
16、ion) or through the use of LAPF procedures defined in Recommendation 4.922 in Frame Relay environments. This Recommendation specifies the detailed mappings between the CO-DLS and X.25/LAPB-compatible, DTE single link procedures as described in Recommendation X.25 and between CO-DLS and the LAPF proc
17、edures described in Recommendation Q.922 in Frame Relay environments. 3) Not applicable. 4) Subclause 2.1, replace with the following: - IT-T Recommendation X.200 (1994) I ISOhEC 7498-1:1994, Information technology - Open Systems Interconnection - Basic Reference Model: The Basic Model. - IT-T Recom
18、mendation X.2 1 O (1993) I ISOLIEC 1073 1 : 1994, Information technology - Open Systems Interconnection - Basic Reference Model: Conventions for the definition of OSI services. - IT-T Recommendation X.212 (1995) I ISOhEC 8886:1996, Information technology - Open Systems Interconnection - Data link se
19、rvice definition. 5) Subclause 2.2, delete this subclause in its entirev and renumber 2.3 as 2.2. Recommendation X.222/Amd.l (10/96) 1 STD-ITU-T RECMN X-222 AMD 1-ENGL L77b 48b2571 Ob31944 774 m 6) New subclause 2.2, replace with the following: - ITU-T Recommendation X.25 (1996), Interface between D
20、ata Terminal Equipment (DTE) and data Circuit-terminating Equipment CE) for terminals operating in the packet mode and connected to public data networks by dedicated circuit. - CCITT Recommendation Q.922 (1992), ISDN data link layer specijcation for ame mode bearer services. - CCITT Recommendation 1
21、.233 (1992), Frame Mode Bearer Services. 7) Clause 3, insert the following as the thirdparagraph: This Recommendation uses the following terms defined in Recommendation 4.922: - LAPF; - Link Release. 8) Clause 4, insert the following abbreviations, by alphabetical order: LAPF Link Access Protocol -F
22、rame Mode SM SetMode 9) Subclause 5. I, replace the third paragraph with the following: When real equipment is considered, a data link consists of two Data Link Entities communicating according to X.25 LAPB-compatible protocol or according to 4.922 LAPF protocol, together with the interconnecting me
23、dia supporting information exchange among the Data Link Entities. 1 O) Subclause 5.2, replace thejrstparagraph with the following: Primitives are abstractions of the behaviour of real systems engaging in data communication; in specifjhg the mapping between these abstract primitives and the activity
24、of real implementations of DL-protocol entities, this allows freedom in modelling the timing of when primitives occur, so as to simpli9 the mapping specification. 1 1) Subclause 5.3, secondparagraph, second sentence, replace with the following: For each mapping, the correspondence is between the DLS
25、DU of a DL-DATA primitive and the basic delimited unit of data transfer in the protocol; that is, the contents of the Information field of a single frame conveying user data. 12) Clause 6, replace the heading of clause 6 with the following: Protocol mapping for X.25 LAPB single link procedure and/or
26、 4.922 LAPF procedures 13) Subclause 6.1, Jirstparagraph, add the following sentence at the end: Recommendation Q.922 supports multiplexing; however, Recommendation X.222 deals with only one DL connection between two DLSAPs. 14) Subclause 6.1, secondparagraph, replace with the following: Table 1 spe
27、cifies the mapping between the principal protocol functions of X.25 LAPB-SLP or 4.922 LAPF and the corresponding features of the OS1 CO-DLS. 15) Subclause 6.1, replace the caption of Table I with the following: Mapping between principal X.25 LAPB or Q.922 LAPF protocol functions and CO-DLS features
28、16) Subclause 6.2, replace thejrstparagraph with the following: Table 2 specifies the mapping between DL-CONNECT primitives and the frames used for link Set-up according to X.25 LAPB or Q.922 LAPF. 2 Recommendation X222/Amd.l (10/96) STD.ITU-T RECMN X.222 AMD 1-ENGL L77b m qb257L Ob3Lqq5 820 m Primi
29、tive 17) Subclause 6.2, replace Table 2 with the following: DL-CONNECT response DL-CONNECT confm Mapping between primitives and X.25 LAPB or Q.922 LAPF frames at DLC establishment UA response transmitted in response to SABM (X.25 LAFB), SABME (X.25 LAPB or 4.922 LAPF) or SM (X.25 LAPB) command recei
30、ved in disconnected mode. UA response received for SABM (X.25 LAPB), SABME (X.25 LAPB or 4.922 LAPF) or SM (X.25 LAPB) command (re)transmitted in disconnected mode. Primitive DL-DISCONNECT request DL-CONNECT request Frame, etc. DISC command transmitted when in information transfer phase, together wi
31、th any retransmissions on timer expiry. DM response transmitted in response to SABM (X.25 LAPB), SABME (X.25 LAPB or 4.922 LAPF), or SM (X.25 LAPB) command received in disconnected mode (reception of DLC establishment). SABM (X.25 LAPB), SABME (X.25 LAPB or 4.922 LAPF) or SM (X.25 LAPB) command tran
32、smitted when in disconnected mode, together with any retransmissions on time expiry. 1 DL-CONNECT indication SABM (X.25 LAPB), SABME (X.25 LAPB or 4.922 LAPF), or SM (X.25 LAFB) command received when in disconnected mode, 1 18) Table 3 specifies the mapping between DL-DISCONNECT primitives and the f
33、rames used for link disconnectionhelease according to X.25 LAPB or 4.922 LAPF. 19) Subclause 6.3, first paragraph, replace with the following: Subclause 6.3, replace Table 3 with the following: DL-DISCONNECT indication DISC command or DM response received when in information transfer phase. DM respo
34、nse received for SABM (X.25 LAPB), SABME (X.25 LAPB or 4.922 LAPF) or SM (X.25 LAPB) command (re)transmitted in disconnected mode (rejection of DLC establishment). DM response transmitted during information transfer phase (in response to received FRMR or unsolicited UA response, or to unsolicited re
35、sponse frame with F bit set to i), together with any retransmissions on timer expiry. Entry to disconnected mode on retransmission-count expiry during information transfer phase or link Set-up. Detection of loss of physical layer communication. I 20) Each DL-DATA request primitive maps to transmissi
36、on of an I-frame, together with any retransmissions required by the X.25 LAPB or Q.922 LAPF procedures for information transfer. Subclause 6.4. first paragraph, replace the first sentence with the following: Recommendation X.222lAmd.l (10/96) 3 STD-ITU-T RECMN X.222 AHD II-ENGL 177b = Li8b2571 Ob314
37、4b 7b7 D 21) Table 4 specifies the mapping between DL-RESET primitives and the frames used for link reset according to X.25 LAPB or 4.922 LAPF procedures. 22) Subclause 6.5, jrst paragraph, replace with the following: Subclause 6.5, secondparagraph, items a) and b), replace with the following: a) “D
38、LS provider” and “Data Link error” if the primitive corresponds to an FRMR response transmitted or received, or to an SABM (X.25 LAPB), SABME (X.25 LAPB or Q.922 LAPF) or SM (X.25 LAPB) command transmitted by the DL-entity in response to an error, or “unknown” and “reason unspecified” when the primi
39、tive corresponds to an SABM (X.25 LAPB), SABME (X.25 LAPB or Q.922 LAPF) or SM (X.25 LAPB) command received. b) 23) Subclause 6.5, Table 4, replace with the following: Mapping between primitives and X.25 LAPB or 4.922 LAPF frames for DLC reserelease 4 Primitive DL-RESET request DL-RESET indication D
40、L-RESET response (Note 2) DL-RESET confirm (Note 2) Frame SABM (X.25 LAPB), SABME (X.25 LAPB or 4.922 LAPF) or SM (X.25 LAPB) command transmitted (Note 1). SABM (X.25 LAPB), SABME (X.25 LAPB or Q.922 LAPF) or SM (X.25 LAPB) command received (Note I). SABM (X.25 LAPB), SABME (X.25 LAPB or 4.922 LAFF)
41、 or SM (X.25 LAPB) command transmitted on receiving unsolicited response frame with F bit set to 1 (Note 1). FRMR response received (Note 1). FRMR response transmitted on entry to frame rejection exception condition (Note 1). Following a DL-RESET indication: UA response transmitted or received, as a
42、ppropriate, to complete a link reset. Time-out waiting for UA response, after sending UA response to a colliding SABM (X.25 LAPB), SABME (X.25 LAPB or 4.922 LAPF) or SM (X.25 LAPB) command received. Following a DL-RESET request: same mapping as for DL-RESET response. Recommendation X.222/Amd.l (10/9
43、6) STD=ITU-T RECMN X-222 AMD 1-ENGL L99b m 48b2591 Ob31447 bT3 m 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 Series S Series T Series U Series V Series X Series Z ITU-T RECOMMENDATIO
44、NS SERIES Organization of the work of the ITU-T Means of expression General telecommunication statistics General tariff principles Telephone network and ISDN Non-telephone telecommunication services Transmission systems and media Transmission of non-telephone signals Integrated services digital netw
45、ork Transmission of sound-programme and television signals Protection against interference Construction, installation and protection of cables and other elements of outside plant Maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits Maintenanc
46、e: international sound-programme and television transmission circuits Specifications of measuring equipment Telephone transmission quality Switching and signalling Telegraph transmission Telegraph services terminal equipment Terminal equipments and protocols for telematic services Telegraph switching Data communication over the telephone network Data networks and open system communication Programming languages STD-ITU-T RECMN X.222 AMD 1-ENGL L79b LIBb259L Ob3LqLiB 53T = *10514* Printed in Switzerland Geneva, 1997
