1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T E.745TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2000) SERIES E: OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS Quality of service, network management and traffic engineering Traffic engineering ISDN traffic engi
2、neering Cell level measurement requirements for the B-ISDN ITU-T Recommendation E.745 (Formerly CCITT Recommendation) ITU-T E-SERIES RECOMMENDATIONS OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS For further details, please refer to ITU-T List of Recommendations.OP
3、ERATION, NUMBERING, ROUTING AND MOBILE SERVICES INTERNATIONAL OPERATION Definitions E.100E.103 General provisions concerning Administrations E.104E.119 General provisions concerning users E.120E.139 Operation of international telephone services E.140E.159 Numbering plan of the international telephon
4、e service E.160E.169 International routing plan E.170E.179 Tones in national signalling systems E.180E.199 Maritime mobile service and public land mobile service E.200E.229 OPERATIONAL PROVISIONS RELATING TO CHARGING AND ACCOUNTING IN THE INTERNATIONAL TELEPHONE SERVICE Charging in the international
5、 telephone service E.230E.249 Measuring and recording call durations for accounting purposes E.260E.269 UTILIZATION OF THE INTERNATIONAL TELEPHONE NETWORK FOR NON-TELEPHONY APPLICATIONS General E.300E.319 Phototelegraphy E.320E.329 ISDN PROVISIONS CONCERNING USERS E.330E.399 QUALITY OF SERVICE, NETW
6、ORK MANAGEMENT AND TRAFFIC ENGINEERING NETWORK MANAGEMENT International service statistics E.400E.409 International network management E.410E.419 Checking the quality of the international telephone service E.420E.489 TRAFFIC ENGINEERING Measurement and recording of traffic E.490E.505 Forecasting of
7、traffic E.506E.509 Determination of the number of circuits in manual operation E.510E.519 Determination of the number of circuits in automatic and semi-automatic operation E.520E.539 Grade of service E.540E.599 Definitions E.600E.699 ISDN traffic engineering E.700E.749 Mobile network traffic enginee
8、ring E.750E.799 QUALITY OF TELECOMMUNICATION SERVICES: CONCEPTS, MODELS, OBJECTIVES AND DEPENDABILITY PLANNING Terms and definitions related to the quality of telecommunication services E.800E.809 Models for telecommunication services E.810E.844 Objectives for quality of service and related concepts
9、 of telecommunication services E.845E.859 Use of quality of service objectives for planning of telecommunication networks E.860E.879 Field data collection and evaluation on the performance of equipment, networks and services E.880E.899 Recommendation E.745 (03/2000) i ITU-T RECOMMENDATION E.745 CELL
10、 LEVEL MEASUREMENT REQUIREMENTS FOR THE B-ISDN Summary This Recommendation provides the requirements to measurements needed at the cell level for an ATM (Asynchronous Transfer Mode)-based B-ISDN (Broadband Integrated Services Digital Network) network. Measurements may be both for real time and for r
11、ecord. The first release of this Recommendation focuses on the latter. This Recommendation is not restricted to point-to-point connections, but covers point-to-multipoint connections as well. Source ITU-T Recommendation E.745 was prepared by ITU-T Study Group 2 (1997-2000) and was approved under the
12、 WTSC Resolution No. 1 procedure on 13 March 2000. ii Recommendation E.745 (03/2000) 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
13、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 (WTSC), which meets every four years, establishes the
14、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 information technology which fall within ITU-Ts purvi
15、ew, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS The ITU draws a
16、ttention 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 applicability of claimed Intellectual Property Rights, whether asserted by ITU members o
17、r 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 to implement this Recommendation. However, implementors are cautioned that this may not
18、 represent the latest information and are therefore strongly urged to consult the TSB patent database. Ge3 ITU 2001 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 perm
19、ission in writing from the ITU. Recommendation E.745 (03/2000) iii CONTENTS Page 1 Scope. 1 2 References. 1 3 Terms and definitions . 2 3.1 Reference events . 2 4 Abbreviations 3 5 Introduction. 4 5.1 Objective of measurements. 4 5.2 Restrictions to this Recommendation . 4 6 Cell-level measurement 5
20、 6.1 Cell-level measurement model . 5 6.2 Cell-level measurement structure . 6 6.2.1 Measurement set information 6 6.2.2 Time information. 6 6.2.3 Destination information of measurement output . 6 7 Traffic flows 6 8 Basic measurement types 7 8.1 General 7 8.1.1 Considerations on UPC/NPC 7 8.1.2 Con
21、siderations on special cells 8 8.1.3 Traffic engineering 8 8.2 Measurements . 8 8.2.1 Overall measurements . 9 8.2.2 Measurements on selectable objects 10 8.2.3 Measurements on control units 11 8.2.4 QOS monitoring 11 9 Recommendation history 12 Annex A Measurement matrix 13 Recommendation E.745 (03
22、/2000) 1 Recommendation E.745 CELL LEVEL MEASUREMENT REQUIREMENTS FOR THE B-ISDN (Geneva, 2000) 1 Scope This Recommendation provides the requirements to measurements needed at the cell level for an ATM (Asynchronous Transfer Mode)-based B-ISDN (Broadband Integrated Services Digital Network) network.
23、 Measurements may be both for real time and for record. The first release of this Recommendation focuses on the latter. This Recommendation is not restricted to point-to-point connections, but covers point-to-multipoint connections as well. 2 References This Recommendation is based on and/or supplem
24、ents the following Recommendations: ITU-T Recommendation E.492 (1996), Traffic reference period. CCITT Recommendation E.502 (1992), Traffic measurement requirements for digital telecommunication exchanges. CCITT Recommendation E.505 (1992), Measurements of the performance of common channel signallin
25、g network. ITU-T Recommendation E.600 (1993), Terms and definitions of traffic engineering. ITU-T Recommendation E.716 (1996), User demand modelling in Broadband-ISDN. ITU-T Recommendation E.726 (2000), Network grade of service parameters and target values for B-ISDN. ITU-T Recommendation E.736 (200
26、0), Methods for cell level traffic control in B-ISDN. ITU-T Recommendation E.737 (1997), Dimensioning methods for B-ISDN. ITU-T Recommendation E.743 (1995), Traffic measurements for SS No. 7 dimensioning and planning. ITU-T Recommendation E.800 (1994), Terms and definitions related to quality of ser
27、vice and network performance including dependability. ITU-T Recommendation G.826 (1999), Error performance parameters and objectives for international constant bit rate digital paths at or above the primary rate. ITU-T Recommendation I.150 (1999), B-ISDN asynchronous transfer mode functional charact
28、eristics. CCITT Recommendation I.321 (1991), B-ISDN protocol reference model and its application. ITU-T Recommendation I.350 (1993), General aspects of quality of service and network performance in digital networks, including ISDNs. ITU-T Recommendation I.353 (1996), Reference events for defining IS
29、DN and B-ISDN performance parameters. ITU-T Recommendation I.356 (2000), B-ISDN ATM layer cell transfer performance. 2 Recommendation E.745 (03/2000) ITU-T Recommendation I.358 (1998), Call processing performance for switched virtual channel connections (VCCs) in a B-ISDN. ITU-T Recommendation I.361
30、 (1999), B-ISDN ATM layer specification. ITU-T Recommendation I.371 (2000), Traffic control and congestion control in B-ISDN. ITU-T Recommendation I.610 (1999), B-ISDN operation and maintenance principles and functions. ITU-T Recommendation I.732 (1996), Functional characteristics of ATM equipment.
31、ITU-T Recommendation M.3010 (2000), Principles for a telecommunications management network. 3 Terms and definitions 3.1 Reference events Figure 1 provides the basis to define the reference events in this Recommendation. T0207940-99Input port Output portMP1MP2MP6MP7MP8MP5MP4ATM layerSwitching matrixT
32、ransmission pathATM layerTransmission pathMP3Cell discarding due to UPC/NPCVC/VP shapingDetection of invalid VCI/VPI cellsCell discarding due to input buffercongestionVC/VP shapingCell discarding due to output buffercongestionTransmissionconvergenceDetection of headererrored cellsInternalphysicallay
33、erTransmissionconvergenceCell discarding due tointernal buffer congestionOutgoinglinkInternalphysicallayerIncominglinkFigure 1/E.745 Measurement points (MPs) inside the network element 3.1.1 incoming cell: A cell entering a generic MP (I.356 cell entry). 3.1.2 outgoing cell: A cell exiting a generic
34、 MP (I.356 cell exit). 3.1.3 UPC/NPC non-conforming cell: A cell which, according to the UPC/NPC device, violates the traffic contract. 3.1.4 UPC/NPC discarded cell: A cell discarded by the UPC/NPC device. Recommendation E.745 (03/2000) 3 3.1.5 lost cell: A cell lost between two different MPs is a c
35、ell received at the first MP but not at the second one, within a time Tmax(this definition is the same as reported in Recommendation I.356). The choice of the two MPs has to be consistent with the observed cell stream. 3.1.6 cell transfer delay across a node: It is defined as the difference between
36、the time at which the first bit of a given cell has completed transmission across MP8 and the time at which the last bit of the same cell had completed transmission across MP1 (this definition is the same as reported in Recommendation I.356). 3.1.7 one-point Cell Delay Variation (CDV): For each cell
37、 of a given connection the one-point CDV is the difference between the cells reference arrival time at a given MP and its actual arrival time (this definition is the same reported in Recommendation I.356). The reference arrival time is defined in Recommendation I.356 and uses the peak cell rate valu
38、e declared by the connection. 3.1.8 buffer occupancy status: Buffer occupancy is measured as the fraction of arriving cells finding the buffer above a given set of thresholds (in the simplest case a single threshold can be used). This measurement provides information useful to derive the cell loss p
39、robability due to buffer congestion, in addition to that obtained from the measurement of the cell loss ratio. As traffic engineering procedures aim at keeping cell losses as rare events, the information obtained from buffer occupancy, being derived from more frequent events, will be more reliable a
40、nd could therefore be considered as the primary source of information on cell loss probability. 3.1.9 number of cell lost due to congestion at input-port, internal, or output-port buffers: The number of cells lost due to congestion at the network element (NE) either at the input, internally or at th
41、e output. The congestion is assumed to take place at input-, internal- or output buffers respectively. The location where cells might be discarded due to buffer congestion is dependent on the node architecture. For example, the architecture could be such that discards due to congestion will occur on
42、ly at output-line cards. Logically, the measurements of cell discards due to congestion need only to be done at locations where such events are designed to occur. 3.1.10 incoming traffic volume: It is defined as the number of incoming cells across MP2 over a fixed time interval T. In this way, we do
43、 not consider cells that are discarded due to header error. 3.1.11 outgoing traffic volume: It is the number of outgoing cells across MP7, counted over a period of fixed length T. 4 Abbreviations This Recommendation uses the following abbreviations: AAL ATM Adaptation Layer ABR Available Bit Rate AT
44、C ATM Transfer Capability ATM Asynchronous Transfer Mode B-ISDN Broadband Integrated Digital Services Network CDV Cell Delay Variation CLP Cell Loss Priority GFC Generic Flow Control GOS Grade of Service HEC Header Error Control MP Measurement Point 4 Recommendation E.745 (03/2000) NE Network Elemen
45、t NP Network Performance NPC Network Parameter Control OAM Operation and Maintenance PTI Payload Type Indicator QOS Quality of Service RM Resource Management TM Traffic Measurements TMN Telecommunications Management Network UNI User-to-Network Interface UPC Usage Parameter Control VCC Virtual Channe
46、l Connection VCI Virtual Channel Identifier VPC Virtual Path Connection VPI Virtual Path Identifier 5 Introduction 5.1 Objective of measurements The objective of the measurement records defined in this Recommendation is to produce data for the following three main categories of purposes: Traffic cha
47、racterization Traffic type classification through cell traffic variables (see Recommendation E.716). Load evaluation. Performance monitoring Monitoring of the GOS provided at the cell level. Traffic control behaviour Monitoring of UPC/NPC actions. Support of ABR mechanisms. Support of ABT mechanisms
48、. Support of adaptive CAC. 5.2 Restrictions to this Recommendation This Recommendation does not specify any specific measurement methods. In Annex C/I.356 some methods are given, which can serve as a guideline for some of the measurement types given below. Annex C/I.356 describes both methods which
49、can be in-service and out-of-service, but it is by no means comprehensive. For instance, passive measurement methods are not covered. This Recommendation does not specify measurements for the physical layer, which are covered in Recommendation G.826. Measurements for cells containing signalling information are for further study, but from a cell level measurement point of view they are merely cells with a special header (see Recommendation I.311). Recommendation E.745 (03/2000) 5 The signall
