1、NTERNATIONAL TELECOMMUN CAT ITU-T TELECOMMUNICATION STAN DARD I ZATION SECTOR OF ITU 1.359 (02/99) SERIES I: INTEGRATED SERVICES DIGITAL NETWORK Overall network aspects and functions - Performance objectives Accuracy and dependability of ISDN 64 kbitls circuit mode connection types ITU-T Recommendat
2、ion I .359 (Previously CCITT Recommendation) STDmITU-T RECMN I-357-ENGL 1979 m 4862571 Ob56452 313 m ITU-T I-SERIES RECOMMENDATIONS INTEGRATED SERVICES DIGITAL NETWORK GENERAL STRUCTURE Terminology Description of ISDNs General modelling methods Telecommunication network and service attributes Genera
3、l description of asynchronous transfer mode Scope General aspects of services in ISDN Common aspects of services in the ISDN Bearer services supported by an ISDN Teleservices supported by an ISDN Supplementary services in ISDN Network functional principles Reference models Numbering, addressing and
4、routing Connection types SERVICE CAPABILITIES OVERALL NETWORK ASPECTS AND FUNCTIONS l.110-1.119 I. 120-1.129 I. 130-1.139 I. 140-1.149 1.1 50-1. I99 I. 200-1.2 O9 1.21 0-1.21 9 I .220-1.229 1.230-1.239 I .240-1.249 I .250-1.299 1.31 0-1.31 9 1.320-1.329 1.330-1.339 1.340-1.349 Performance objectives
5、 1.350-1.359 Protocol layer requirements General network requirements and functions Application of I-series Recommendations to ISDN user-network interfaces Layer 1 Recommendations Layer 2 Recommendations Layer 3 Recommendations Multiplexing, rate adaption and support of existing interfaces Aspects o
6、f ISDN affecting terminal requirements ISDN USER-NETWORK INTERFACES INTERNETWORK INTERFACES MAINTENANCE PRINCIPLES B-ISDN EQUIPMENT ASPECTS ATM equipment Transport functions Management of ATM equipment I .360-1.369 1.370-1.399 1.420-1.429 1.430-1.439 1.440-1.449 1.450-1.459 I .460-1.469 1.470-1.499
7、1.500-1.599 1.600-1.699 1.730-1.739 1.740-1.749 1.750-1.799 Forjkrther details, please rer to ITU-T List of Recommendations. STD*ITU-T RECMN 1.359-ENGL 1999 4862593 Ob56453 25T ITU-T RECOMMENDATION 1.359 ACCURACY AND DEPENDABILITY OF ISDN 64 kbit/s CIRCUIT MODE CONNECTION TYPES Summary This Recommen
8、dation defines parameters for assessing the accuracy and dependability performance of call processing in an Integrated Services Digital Network (ISDN) provided in accordance with Recommendations identified herein. The defined parameters apply to ISDN services using a single B-channel and associated
9、D-channel; planned revisions to this Recornmendation will address other ISDN bearer services (e.g. n x 64 kbit/s and primary rate connection types). Source ITU-T Recommendation 1.359 was prepared by ITU-T Study Group 13 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 1
10、5th of February 1999. Recommendation 1.359 (02/99) 1 - - FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsibl
11、e 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 (WTSC), which meets every four years, establishes the topics for study by the ITU-
12、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 information technology which fall within ITU-Ts purview, the necessary standards
13、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 public correspondence service. The terms Administration, ROA and public correspond
14、ence are defined in the Constitution of the ITU (Geneva, 1992). INTELLECTUAL PROPERTY EUGHTS 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 ev
15、idence, 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, the ITU had not received notice of intellectual property, protected by patents, w
16、hich 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 All rights reserved. No part of this publication may be reproduced or utilized
17、 in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. II Recommendation 1.359 (02/99) 1 2 3 4 4.1 4.2 STD-ITU-T RECMN 1.359-ENGL 1999 W 48625911 Ob56455 O22 CONTENTS Page Scope References Abbreviations . Accuracy and
18、 dependability parameters and objectives . Access parameters Connection Set-up error probability (CSEP) . Connection set-up failure probability (CSFP) . Disengagement parameters . 4.1.1 4.1.2 4.2.1 Premature disconnect parameters 4.2.2 Connection clearing failure probability (CCFP) . 1 3 3 . Recomme
19、ndation 1.359 (02/99) 111 - STD-ITU-T RECMN 1-359-ENGL 1999 D 4Bb2591 ObSbtCb Tb9 = Recommendation 1.359 ACCURACY AND DEPENDABILITY OF ISDN 64 kbit/s CIRCUIT MODE CONNECTION TYPES 1 Scope This Recommendation defi (Geneva, 1999) es parameters for assessing th accuracy and dependability erformance of
20、call processing in an Integrated Services Digital Network (ISDN) provided in accordance with Recommendations identified herein. The defined parameters apply to ISDN services using a single B-channel and associated D-channel; planned revisions to this Recommendation will address other ISDN bearer ser
21、vices (e.g. n x 64 kbit/s and primary rate connection types), The scope of this Recommendation and its relationship with other Recommendations is illustrated in Figure 1. Recommendation 1.353 defines measurement points and reference events at which ISDN circuit mode connection processing performance
22、 parameters may be defined. Recommendation 1.3 53 also defines a 3 x 3 matrix that can be used in organizing and classiQing performance parameters. Three protocol-independent data communication functions are identified in the matrix: access, user information transfer, and disengagement. Each functio
23、n is considered with respect to three general performance concerns (or “performance criteria“): speed, accuracy, and dependability. Recommendation 1.3 59 defines a set of primary parameters that describe accuracy and dependability performance relative to the access and disengagement functions. Speci
24、fied values for these parameters may be compared with corresponding outage thresholds in determining 64 kbit/s availability performance. The availability function and availability parameters are defined in Recommendation 1.355. Additional 64 kbitls performance parameters applicable to ISDNs are defi
25、ned in Recommendations 1.352 and G.82 1. Recommendation 1.359 (02/99) 1 STD-ITU-T RECMN I-359-ENGL L997 H 4862593 ObSb457 9T5 m 2 : Network section : PhySical Phyiical interface interface a . DTE : Circuit section : DTE or : : or DSE i : DSE tf - Phy Sical Phy Sical interface in terface . ISDN circu
26、it mode reference events transfer isengagement /I Rec. G.821 Ti31 310-98 CSEP Connection Set-up Error Probability CSFP Connection Set-up Failure Probability PDP Premature Disconnect Probability CCFP Connection Clearing Failure Probability Figure 1A.359 - Scope of Recommendation 1.359 Recommendation
27、1.359 (02/99) STD-ITU-T RECMN 1.359-ENGL 1999 H 4862593 ObSb458 831 2 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 va
28、lid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommenda
29、tions is regularly published. ITU-T Recommendation 1.3 52 (1 993), Network performance objectives for connection processing delays in an ISDN. ITU-T Recommendation 1.353 (1996), Reference events for defining ISDN and B-ISDN performance parameters. ITU-T Recommendation 1.355 (1995), ISDN 64 kbit/s co
30、nnection type availability performance ITU-T Recommendation 4.92 1 (1 997), ISDN user-network interface - Data link layer specijcation. ITU-T Recommendation Q.93 1 (1.45 1) (1 998), ISDN user-network interface layer 3 speciJication for basic call control. ITU-T Recommendation Q.764 (1997), Signallin
31、g System No. 7 - ISDN User Part signalling procedures. Abbreviations This Recommendation uses the following abbreviations: ANS CCFP CSEP CSFP DSE DTE IAM ISDN ITU-T MPI MPT PDP PDS RE ss7 TE Answer Connection Clearing Failure Probability Connection Set-up Error Probability Connection Set-up Failure
32、Probability Data Service Equipment Data Terminal Equipment Initial Address Message Integrated Services Digital Network International Telecommunications Union - Telecommunication Standardization Sector Measurement Point International Measurement Point Terminal Premature Disconnect Probability Prematu
33、re Disconnect Stimulus Reference Event Signalling System 7 Terminal Equipment Recommendation 1.359 (02/99) 3 - STDOITU-T RECMN 1.359-ENGL 1799 W 48b2571 Ob5b459 778 4 This clause defines accuracy and dependability parameters for unrestricted digital connection types provided using ISDN circuit mode
34、bearer services. These accuracy and dependability parameters can be measured or estimated at any pair of boundaries delimiting a portion or concatenation of portions. Accuracy and dependability parameters and objectives 4.1 Access parameters Two circuit mode access parameters, connection Set-up erro
35、r probability and connection Set-up failure probability, are defined in 4.1.1 and 4.1.2. Connection Set-up error and connection set-up failure are defined between pairs of portion boundaries (Bi, Bj). Bi is one of the set of boundaries to which the connection Set-up attempt can properly be routed. F
36、igure 2 identifies the sequence of four particular events that occur at these boundaries during a successful connection Set-up. A connection Set-up attempt over this portion is a sequential occurrence of corresponding events a), b), c), d) prior to expiration of timer T301 5. Connection Set-up error
37、s and connection Set-up failures within this portion are defined below. Any other unsuccessful connection Set-up attempt is caused by problems outside the portion and is excluded from the measurement. Bi Bj Tl313820-98 Figure 2fi.359 - Circuit mode reference events occurring during successful connec
38、tion Set-up 4.1.1 Connection Set-up error probability is the ratio of total connection Set-up attempts that result in connection set-up error to the total connection Set-up attempts in a population of interest. With reference to Figure 2, a connection Set-up error is defined to occur on any connecti
39、on Set-up attempt in which event d) occurs, but event c) does not occur at an appropriate boundary prior to expiration of timer T30 1. Connection Set-up error is essentially the case of a network-caused “wrong number”. It occurs when the network responds to a valid connection request by erroneously
40、establishing a connection to a destination Terminal Equipment (TE) other than the one designated in the connection request, and does not correct the error prior to the user information transfer. It may be caused, for example, by network operator administrative or maintenance actions. Connection Set-
41、up error probability (CSEP) 4 Recommendation 1,359 (02/99) - STD*ITU-T RECMN 1.357-ENGL 1977 4862591 Ob5bYbO 49T MPT, Connection Set-up error is distinguished from successful connection Set-up by the fact that the intended called user is not contacted and not committed to the session during the conn
42、ection Set-up attempt. The specific Recommendation 1.3 53 Reference Events (RES) used in measuring successful connection Set-up at each portion boundary are those identified in Table 1 and Table 2. 4 d) P 1 a (SETUP exit) P6b (CONNECT entry) Table 1iI.359 - RES at Bi occurring during successful ISDN
43、 circuit mode connect Set-up MP12 MPT, Boundary Bi S 1 b (IAM entry) S3aTANS exit) Not applicable Not applicable Reference event I I I I Table 2fl.359 - RES at Bj occurring during successful ISDN circuit mode connect Set-up I Reference event I Boundary Bi I I t I I I MPTI I Not applicable I Not appl
44、icable I I MPI, I Sla (IAM exit) I S3b (ANS entry) I I MPI2 I Slb(1AMentry) 1 3a (ANS exit) I I MPT2 I PI b (SETUP entry) I P6a(CONNECTexit) I I NOTE -En bloc and overlap sending options are defined at the MPT, interface. 4.1.2 Connection Set-up failure probability is the ratio of total connection S
45、et-up attempts that result in connection set-up failure to the total connection Set-up attempts in a population of interest. With reference to Figure 2, connection Set-up failure is defined to occur on any connection Set-up attempt in which either one of the following outcomes is observed prior to e
46、xpiration of timer T301. - - The specific reference events are those defined in Tables 1 and 2. Connection Set-up attempts that are cleared by the portion as a result of incorrect performance or non-perfonnance on the part of an entity outside the portion are excluded. A connection Set-up attempt ca
47、n fail as a result of user blocking. Such failures are excluded from network performance measurement. Examples of user blocking include the following: - - Connection Set-up failure probability (CSFP) both events b) and d) do not occur; events b) and c) occur, but event d) does not. the called user i
48、ssues a message to reject the call Set-up attempt; the CONNect message (P6b) reference event fails to occur at the originating MPT boundary due to the lack of a CONNect message (P6a) reference event at the terminating MPT boundary; Recommendation 1.359 (02/99) 5 - STDmITU-T RECMN 1-359-ENGL 1999 = 4
49、8b2591 Ob5b4bL 32b - the called user delays excessively in generating the CONNect message (P6a) reference event during the connection period, with the result that a connection is not established before the time-out; all channels at the called TE are in use. - 4.2 Disengagement parameters This subclause defines two new disengagement parameters: premature disconnect probability and connection clearing failure probability. The definition of a third parameter, premature disconnect stimulus probability, is for further study. 4.2.1 Prematu
