1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU E.460 (03/2000) SERIES E: OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS Quality of service, network management and traffic engineering - Network management - Checking the q
2、uality of the international telephone service Measurements and metrics for monitoring the performance of V.34 Group 3 facsimile ITU-T Recommendation E.460 (Formerly CCITT Recommendation) ITU-T E-SERIES RECOMMENDATIONS OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS
3、OPERA TION, NUMBERING, ROUTING AND MOBILE SERVICES INTERNATIONAL OPERATION Definitions General provisions concerning Administrations General provisions concerning users Operation of international telephone services Numbering plan of the international telephone service International routing plan Tone
4、s in national signalling systems Maritime mobile service and public land mobile service OPERATIONAL PROVISIONS RELATING TO CHARGING AND ACCOUNTING IN THE INTERNATIONAL TELEPHONE SERVICE Charging in the international telephone service Measuring and recording call durations for accounting purposes UTI
5、LIZATION OF THE INTERNATIONAL TELEPHONE NETWORK FOR NON- TE LEP H ONY AP PLI CATI ONS General Phototelegraphy ISDN PROVISIONS CONCERNING USERS QUALITY OF SERVICE, NETWORK MANAGEMENT AND TRAFFIC ENGINEERING NETWORK MANAGEMENT International service statistics International network management - Checkin
6、g the quality of the international telephone service TRAFFIC ENGINEERING Measurement and recording of traffic Forecasting of traffic Determination of the number of circuits in manual operation Determination of the num ber of circuits in automatic and semi-automatic operation Grade of service Definit
7、ions ISDN traffic engineering Mobile network traffic engineering QUALITY OF TELECOMMUNICATION SERVICES: CONCEPTS, MODELS, OBJECTIVES AND DEPENDABILITY PLANNING Terms and definitions related to the quality of telecommunication services Models for telecommunication services Objectives for quality of s
8、ervice and related concepts of telecommunication services Use of quality of service objectives for planning of telecommunication networks Field data collection and evaluation on the performance of equipment, networks and services E. 1 00-E. 103 E.104-E.119 E. 120-E. 139 E. 140-E. 159 E. 1 60-E. 1 69
9、 E. 170-E. 179 E. 1 80-E. 1 99 E.200-E.229 E.230-E.249 E.260-E.269 E.300-E.319 E.320-E.329 E. 330-E. 399 E.400-E.409 E.41 0-E.419 E.490-E.505 E.506-E509 E.510-E519 E.520-E539 E.540-E599 E.600-E.699 E.700-E.749 E.750-E.799 E.800-E.809 E.810-E.844 E.845-E.859 E.860-E.879 E.880-E.899 For further detail
10、s, please rer to ITD-T List of Recommendations. ITU-T RECOMMENDATION E.460 MEASUREMENTS AND METRICS FOR MONITORING THE PERFORMANCE OF V.34 GROUP 3 FACSIMILE Summary This Recommendation describes measurements and metrics for monitoring the performance of V.34 group 3 facsimile. There are two options
11、in T.30 for V.34 fax over the PSTN. These are described in Annexes C and F of T.30. At present no known implementations use Annex UT.30; they use either Annex F/T.30 or some other proprietary method. It is possible to map many of the measurements and metrics from E.459 onto monitoring of V.34 fax. S
12、ource ITU-T Recommendation E.460 was prepared by ITU-T Study Group 2 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on 13 March 2000. Recommendation E.460 (03/2000) 1 FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of
13、 telecommunications. The ITU Telecommunication Standardization 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
14、 World Telecommunication Standardization Conference (WTSC), 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
15、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 collaborative basis with IS0 and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a teleco
16、mmunication administration and a recognized operating agency. 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 evid
17、ence, 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, whi
18、ch 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 2000 All rights reserved. No part of this publication may be reproduced or utilized i
19、n any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing fi-om the ITU. 11 Recommendation E.460 (03/2000) CONTENTS 1 Scope . 2 Call data measurements 3 Cumulative data measurements 3.1 Cumulative data measurements based on T.30 protoco
20、l messages 4 Metrics 4.1 Primary metrics . 4.2 Secondary metrics . 4.3 Optional metrics Recommendation E.460 (03/2000) Page 1 iii Introduction This Recommendation describes measurements and metrics for monitoring the performance of V.34 group 3 facsimile. There are two options in T.30 for V.34 fax o
21、ver the PSTN. These are described in Annexes C and F of T.30. At present no known implementations use Annex UT.30; they use either Annex F/T.30 or some other proprietary method. It is possible to map many of the measurements and metrics fiom E.459 onto monitoring of V.34 fax. The important differenc
22、es between normal G3 fax and T.30 Annex F are: o error correction mode is mandatory; Annex F/T.30 uses the half duplex mode defined in V.34; the handshaking is performed over the duplex control channel defined in V.34; the transmission rate of the high speed image phase and the control channel hands
23、haking is the fiame structure of the binary coded signals used over the control channel is the same as the TCF and FTT fiames are not used; V.34 procedures; o o o negotiated using V.34 procedures not T.30 fallback; that used for normal G3 fax in error correction mode; o o o rate changes in both prim
24、ary and control channels can occur during a call using o each call begins with a V.8 capabilities exchange (this also applies to T.30 Annex C calls). In order to measure the performance of a V.34 fax call, it will be necessary to monitor and decode theV.8 start-up and the V.34 control channel. The V
25、.8 information is transmitted using V.21 modulation. The V.34 control channel is transmitted using 1200 or 2400 bih QAM. The rates may be asymmetric. This Recommendation assumes that it is possible to reliably extract information rom the control channel. The rest of this Recommendation suggests meas
26、urements and metrics appropriate for T.30 Annex F fax. Where possible they correspond to those already defined in E.459. Only protocol related measurements are described. Many of the image, analogue and signalling related call data measurements described in Annexes A, B and C of E.459 are also relev
27、ant. The names of the measurements and metrics defined in this Recommendation are the same as those in E.459. However, in this case they apply only to V.34 fax calls according to T.30 Annex F. T.30 Annex C measurements and metrics are for Mer study. iv Recommendation E.460 (03/2000) Recommendation E
28、.460 MEASUREMENTS AND METRICS FOR MONITORING THE PERFORMANCE OF V.34 GROUP 3 FACSIMILE (Geneva, 2000) 1 Scope This Recommendation describes measurements and metrics for monitoring the performance of V.34 group 3 facsimile. There are two options in T.30 for V.34 fax over the PSTN. These are described
29、 in Annexes C and F of T.30. At present no known implementations use Annex UT.30; they use either Annex F/T.30 or some other proprietary method. It is possible to map many of the measurements and metrics fiom E.459 onto monitoring of V.34 fax. The important differences between normal G3 fax and T.30
30、 Annex F are: o error correction mode is mandatory; Annex F/T.30 uses the half duplex mode defined in V.34; the handshaking is performed over the duplex control channel defined in V.34; the transmission rate of the high speed image phase and the control channel handshaking is the fiame structure of
31、the binary coded signals used over the control channel is the same as the TCF and FTT fiames are not used; V.34 procedures; o o o negotiated using V.34 procedures not T.30 fallback; that used for normal G3 fax in error correction mode; o o o rate changes in both primary and control channels can occu
32、r during a call using o each call begins with a V.8 capabilities exchange (this also applies to T.30 Annex C calls). In order to measure the performance of a V.34 fax call, it will be necessary to monitor and decode theV.8 start-up and the V.34 control channel. The V.8 information is transmitted usi
33、ng V.21 modulation. The V.34 control channel is transmitted using 1200 or 2400 bih QAM. The rates may be asymmetric. This Recommendation assumes that it is possible to reliably extract information fiom the control channel. The rest of this Recommendation suggests measurements and metrics appropriate
34、 for T.30 Annex F fax. Where possible they correspond to those already defined in E.459. Only protocol related measurements are described. Many of the image, analogue and signalling related call data measurements described in Annexes A, B and C of E.459 are also relevant. The names of the measuremen
35、ts and metrics defined in this Recommendation are the same as those in E.459. However, in this case they apply only to V.34 fax calls according to T.30 Annex F. T.30 Annex C measurements and metrics are for Mer study. 2 Call data measurements The following measurements must be recorded for each call
36、. Measurements are either “information“, which can be extracted fiom T.30 protocol messages, or simple “yes/no“ decisions on whether a condition was met. Where the type or contents of T.30 fiames must be analysed, the fiame must have a correct CRC. Recommendation E.460 (03/2000) 1 Pages sent at high
37、est rate Information Pages sent at lower rates Information Final primary channel transmission rate Information T.30 Annex F Yesno Caller transmits Yesno In ECM calls, capture PPR and corresponding PPS frames Information 64 octet frames Y esno CIG Information If present. Last frame of the call in eac
38、h direction Information To determine whether call is complete, and if not, to provide diagnostic information. Recording of frames immediately before the last fiame in each direction may be necessary and is for further study. Call complete Yesno Detected MCF followed by DCN. “No“ indicates an incompl
39、ete call. Disconnect after DCS I Yesno I Precise condition needs to be defined. I DCN from transmitter I Yesno I I DCN from receiver I Yesno I I NSS or NSC detected I Yesno I Indicates a non-standard call. I CNG only I Yesno May indicate a misdialled fax call. I DIS or ANSam and DIS only I Yesno May
40、 indicate a misdialled voice call. I Number of pages sent at initially negotiated primary channel rate. Number of pages sent after 1 or more retrains on primary channel. I Information 1 st choice primary channel transmission rate Extracted from MPh sequence. 1 st choice control channel transmission
41、rate Information Extracted from MPh sequence. Note the higher of the two rates if asymmetric. Extracted from MPh sequence. Note the higher of the two rates if asymmetric. “yes“ indicates T.30 Annex F procedures. “no“ indicates T.30 Annex C procedures. Extracted fiom V.8 message. “no“ indicates calle
42、r receives. captured beyond the 10th partial page. “yes“ implies 64 octet fiames. “no“ implies 256 octet fiames. 2 Recommendation E.460 (03/2000) 3 Cumulative data measurements B C 3.1 The following data must be generated rom the individual call data measurements. The cumulative data is used to gene
43、rate the primary, secondary and optional metrics, as indicated in the columns headed P, S and O in the table below. The following definitions are for the purposes of this Recommendation only: A fax call is a call where the V.8 JM message indicates T.30 Annex F operation i.e. ANSam + DIS without any
44、fax signal rom the calling end does not constitute a fax call as this may be a misdialled voice call. Image quality as observed at the monitor point during transmission is defined as: Cumulative data measurements based on T.30 protocol messages Pages with greater than 3% but less than 10% errored fr
45、ames (Note) Pages with 10% or greater errored fiames (Note) I A I Pages with 3% or less errored fiames (Note) I Name What How Comments PSO T Total number of fax calls fax calls Total number of standard facsimile calls which complete OK Number of calls which I FIB I disconnect after DCS Number of cal
46、ls which fail after CFR completely fail to train Calls in which NSS or NSC is not returned. See definition of fax call above Defined to be all fax calls except those which use non-standard facilities Calls ending with MCF, DCN and do not contain NSS or NSC No CFR detected No post page response (MCF
47、or PPR) extremely poor quality V V V V V V V V Recommendation E.460 (03/2000) 3 Name What How Comments PSO cl Number of calls which connect at first choice transmission rate cR V.34 trains at maximum rate (28.8 or above?) Number of completed calls which connect at first choice transmission rate but
48、retrain to lower rate after one or more pages sent Primary channel retrains during call after initially connecting at max rate cB Primary channel initially trains at below max rate and retrains during call Number of completed calls with fallback Maximum rate is 33.6 kbits at present. However, many e
49、arlier V.34 implementations are only capable of 28.8 kbits Ci;m;x CB;m;x “m“ = V.34 in this case x varies fiom 2.4 to 33.6 kbits Number of calls which connect with first choice transmission rate using modulation type “m“ and transmission rate “x“ Number of calls retrain to modulation type “m“ and minimum transmission rate “x“ “m“ = V.34 in this case x varies fiom 2.4 to 3 1.2 kbits IEQ i IEQ2 Number of calls which have image quality A Number of calls which have image quality B IEQ3 Number of calls which have image quality C Number of ECM calls in which at least on
