1、INTERNATIONAL TELECOMMUNICATION UN ION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU X.124 (06/99) SERIES X: DATA NETWORKS AND OPEN SYSTEM COMMUNICATIONS Public data networks - Network aspects Arrangements for the interworking of the E.164 and X.121 numbering plans for frame relay and ATM ne
2、tworks ITU-T Recommendation X.124 (Previously CCITT Recommendation) ITU-T X-SERIES RECOMMENDATIONS DATA NETWORKS AND OPEN SYSTEM COMMUNICATIONS UBLIC DATA NETWORKS Services and facilities Interfaces X. 1-X. 19 X.20-X.49 Transmission, signalling and switching X.50-X.89 Maintenance Administrative arra
3、ngements )PEN SYSTEMS INTERCONNECTION Model and notation Service definitions Connection-mode protocol specifications Connectionless-mode protocol specifications PICS proformas Protocol Identification Security Protocols Layer Managed Objects Conformance testing 1NTERWORKING BETWEEN NETWORKS General S
4、atellite data transmission systems MESSAGE HANDLING SYSTEMS DIRECTORY OS1 NETWORKING AND SYSTEM ASPECTS Networking Efficiency Quality of service Naming, Addressing and Registration Abstract Syntax Notation One (ASN.l) OS1 MANAGEMENT Systems Management framework and architecture Management Communicat
5、ion Service and Protocol Structure of Management Information Management functions and ODMA functions SECURITY OS1 APPLICATIONS Commitment, Concurrency and Recovery Transaction processing Remote operations OPEN DISTRTBUTED PROCESSING X. 150-X. 179 X. 180-X. 199 ? X.200-X.209 X.2 1 O-X .2 1 9 X.22-X.2
6、29 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.4wx.499 X.500-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.710-X.719 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 Forfurther
7、 details, please refer to ITU-T List of Recommendations. ITU-T RECOMMENDATION X.124 ARRANGEMENTS FOR THE INTERWORKING OF THE E.164 AND X.121 NUMBERING PLANS FOR FRAME RELAY AND ATM NETWORKS Summary This Recommendation defines the procedures applicable for the purpose of numbering pian interworking b
8、etween ATM networks which use the E.164 numbering plan and Public Frame Relay Data Networks which may use either the X.121 numbering pian or the E.164 numbering plan. The principles for interworking between the E.164 and X.121 numbering pians covered in this Recommendation are illustrated by various
9、 examples. The scenario (for FWATM service interworking) where the ATM terminal is identified by an AESA (NSAP) is also illustrated. Source ITU-T Recommendation X.124 was prepared by ITU-T Study Group 7 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 18th of June 1999.
10、Recommendation X.124 (06/99) 1 - - FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommuni- cations. The ITU Telecommunication Standardization Sector TU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technic
11、al, operating and tariff questions and issuing Recommendations 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 for study by the ITU-T Study Groups which,
12、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 information technology which fall within ITU-Ts purview, the necessary standards are prepared on a coll
13、aborative 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 public correspondence service. The terms Administration, ROA and public correspondence are defined in th
14、e 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 claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or ap
15、plicability 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, the ITU had not received notice of intellectual property, protected by patents, which may be required t
16、o 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 All rights reserved. No part of this publication may be reproduced or utilized in any foim or by any
17、 means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. 11 Recommendation X.124 (06/99) CONTENTS Page 1 Introduction 1 2 Scope 1 3 References 2 4 Definitions 2 5 Abbreviations . 2 6 Interworking . 3 6.1 Numbering plans . 3 6.2 Methods . 4 6
18、.3 Terminal dialling procedures 5 7 Interworking diagrams 5 7.1 Conventions used in the interworking diagrams . 5 7.3 Interworking diagrams 7 7.2 Index of interworking diagrams 6 Recommendation X.124 (06/99) . 111 Recommendation X.124 ARRANGEMENTS FOR THE INTERWORKING OF THE E.164 AND X.121 NUMBERIN
19、G PLANS FOR FRAME RELAY AND ATM NETWORKS (Geneva, 1999) 1 Introduction Public B-ISDN (ATM) networks utilize the E.164 numbering plan, whilst Public Frame Relay Data Networks (PFRDNs) may be numbered under either the X.121 numbering plan or the E.164 numbering plan. A call from a B-ISDN (E.164) to a
20、PFRDN (X.l21), a PFRDN (X.121) to a PFRDN (E.164) and calls routed through networks using a different numbering plan to that of the originating or destination network are examples of the need for numbering plan interworking. Numbering plan interworking is a fundamental requirement for the successful
21、 completion of calls between data networks utilizing different numbering plans. This Recommendation defines the general procedures applicable to numbering plan interworking between: - Public Frame Relay Data Networks which utilize differing numbering plans; - Public Frame Relay Data Networks and B-I
22、SDNs (Public ATM Networks). The numbering and addressing principles for B-ISDNs are described in Recommendation E.191. The numbering principles for public data networks are defined in Recommendation X.121. NOTE - Within this Recommendation the term Public Frame Relay Data Network can be used interch
23、angeably with the term Public Data Network providing the Frame Relay Data Transmission Service. The term ATM Network can be used interchangeably with the term B-ISDN. 2 Scope 2.1 The scope of this Recommendation is to define the procedures applicable for the purpose of numbering plan interworking be
24、tween B-ISDN (Public ATM Networks) and Public Frame Relay Data Networks utilizing the E. 164 numbering plan and those Public Frame Relay Data Networks which use the X.121 numbering plan. 2.2 The principles for interworking between the E.164 and X.121 numbering plans covered in this Recommendation ar
25、e illustrated by various examples which involve only Frame Relay calls. The scenario (for FWATM service interworking) where the ATM terminal is identified by an AESA (NSAP) is also illustrated. The numbering plan interworking principles utilize the Numbering Plan Identifier (NPI) method. 2.3 Recomme
26、ndation. Interworking involving two or more Frame Relay or ATMNetworks is included in the scope of this 2.4 calls within a single country is a national matter. This Rec,ommendation applies to numbering plan interworking across network boundaries. Its applicability to Recommendation X.124 (06/99) 1 -
27、 STD.ITU-T RECMN Xm1i!4-ENGL 1999 m 4b2591 OhhQ359 900 3 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Reco
28、mmendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valir ITU-T Recommendations is regularly published.
29、 ITU-T Recommendation E. 164 (1997), The international public telecommunications numbering plan. ITU-T Recommendation 1.555 ( 1997), Frame Relaying Bearer Service intenvorking. ITU-T Recommendation X.36 (1995). Intelface between Data Terminal Equipment (DTE) and Data Circuit- terminating Equipment (
30、DCE) for public data networks providing frame relay data transmission service by dedicated circuit. ITU-T Recommendation X.36/Amd.l (1996), Switched Virtual Circuit (SVC) signalling and refinements of Permanent Virtual Circuit (PVC) signalling. ITU-T Recommendation X.36/Amd.2 (1997), Frame transfer
31、priority. ITU-T Recommendation X.36/Amd.3 (1998), Frame discard priorily, service classes, NSA P signalling and protocol encapsulation ITU-T Recommendation X.46 (1998), Access to FRDTS via B-1SDN. ITU-T Recommendation X.76 (1993, Network-to-network interface between public data networks providing th
32、e frame relay data transmission service. ITU-T Recommendation X.76/Amd. 1 (1997), Switched virtual circuits. ITU-T Recommendation X.76/Amd.2 (1998), Frame relay service classes and priorities. ITU-T Recommendation X. 121 (1996), International numbering plan for public datu networks. ITU-T Recommenda
33、tion X. 122 (1998), Numbering plan interworking for the E. 164 and X. 121 numbering plans. ITU-T Recornmendation X. 123 (1996), Mapping between escape codes and TOA/NPl for E. J64X. 121 numbering plan intenvorking during the transition period. ITU-T Recommendation X.300 (1996), General principles fo
34、r intenvorking between public networks and between public networks, and other networks for the provision of data transmission services. ITU-T Recommendation X.301 (1996), Description of the general arrangements for call control within a subnetwork and between subnetworks for the provision of data tr
35、ansmission services. Definitions A list of terms and their definitions relating to numbering are contained in Recommendations E.164 and X.121. 5 Abbreviations This Recommendation uses the following abbreviations: AESA ATM End System Address ALT-ADD Alternative Address ATM Asynchronous Transfer Mode
36、AU Access Unit B-ISDN CSM Call Set-up Message DCE Data Circuit-terminating Equipment DNIC Data Network Identification Code Broadband Integrated Services Digital Network 2 Recommendation X.124 (06199) DTE FR FRDTS ND NPI NSAP PDN PFRDN STE TON Data Terminal Equipment Frame Relay Frame Relay Data Tran
37、smission Service Number Digits Numbering Plan Identification Network Service Access Point (address) Public Data Network Public Frame Relay Data Network Signalling Terminal Equipment Type of Number 6 Interworking The sample call flows shown in the figures are from terminal to terminal. The applicatio
38、n of this Recommendation includes the following numbering pian interworking scenarios: a) calls frondto a frame relay terminal on a PFRDN numbered under X.121, to/from a PFRDN numbered under E.164; b) calls frodto an ATM terminai with frame relay capabilities on an ATM Network numbered under E. 164,
39、 tolfrom a frame relay terminai on a PFRDN numbered under X. 121; c) calls frondto a frame relay terminal on a PFRDN numbered under X.121. utilizing an ATM Network as a transit network for calls to/from a frame relay terminal on a PFRDN numbered under X. 121; d) calls frondto a frame relay terminal
40、on a PFRDN numbered under X.121, utilizing an ATM Network as a transit network for calls to/from a frame relay terminal on a PFRDN numbered under E. i 64; e) calls from/to a frame relay terminal on a PFRDN numbered under X.121, to/from an ATM terminal on an ATM Network numbered under E. 164 (service
41、 interworking); f) calls frondto a frame relay terminal on a PFRDN numbered under X.121, to/from an ATM terminal on an ATM Network identifed by an AESA (OS1 NSAP) (service interworking). NOTE - The interworking scenario for calls frodto a frame relay terminal on an ATM Network numbered under E. 164,
42、 utilizing a PFRDN numbered under X.121 as a transit network for calls to/from a frame relay terminal on an ATM Network numbered under E.164 is for further study. 6.1 Numbering plans The two numbering plans included in the arrangements shown in this Recommendation are the E.164 and the X.121 numberi
43、ng plans. 6.1.1 Escape codes For the purpose of number plan interworking for the provision of Frame Relay Data Services, escape codes are not used. 3 Recommendation X.124 (06/99) 6.1.2 Prefixes Definitions of prefixes are contained in Recommendations E.164 and X.121. Since for the purposes of interw
44、orking the full international number format is used, the use of prefixes is not required within the scope of this Recommendation. 6.2 Methods In the diagrams that are included in this Recommendation, there are two main situations when numbering plan interworking occurs. One situation is when a termi
45、nal is placing a call and must indicate to the originating switch that numbering plan interworking is involved. The other is when one switching system is passing a call over a trunk to another switching system and must indicate to the receiving switching system that interworking is involved. Differe
46、nt methods of accomplishing numbering plan interworking are portrayed in the diagrams in this Recommendation. 6.2.1 Dial-in method The dial-in method of numbering plan interworking occurs when a terminai on one network places a call that terminates on an Access Unit (AU) of another network that uses
47、 the numbering plan of the called terminal. When the call from the originating terminal reaches the access unit, it appears to the second network simply as a call origination. Thus, the calling terminal establishes the call by using a two-step process. In the first step, the calling terminal enters
48、the called party number in the originating networks numbering plan. The call proceeds to a termination point on the first network which is also an origination point on the second network. The calling terminal receives the equivalent of dial tone from the second network and then enters the called par
49、ty number using the numbering plan of the called terminal. Except for access unit functions, neither network needs to have a switching system that deals with numbering plan interworking. 6.2.2 NPI method The Numbering Plan Identification (NPI) method is a protocol technique by which the called or calling party number, which may come from either the X.121 or E.164 numbering plan, can be specified in an unambiguous manner, since the numbering plan is clearly and uniquely identified by the coding in the NPI field of the calledkalling party number. This method requires the
