1、 54-2 Page 1 E Recommendation T/CS 54-12 (Montpellier 1984) TRAFFIC MEASUREMENTS Recommendation proposed by Working Group T/WG 11 “Switching and Signalling” (CS) Text of the Recommendation adopted by the “Telecomniimicatio12s” Commission : “The European Conference of Postal and Telecommunications Ad
2、ministrations, considering - that digital local and transit exchanges are increasingly used in CEPT-countries; - that it could be advantageous to conceive a set of trafic measurement types suitable for several exchange systems - that administrations have the responsibility for the measurements durin
3、g the whole time the equipment concerned - that it is desirable to harmonise functions for trafic measurements in CEPT-countries, recommends that the members of the CEPT use for trafic measurement the structure and measurement types set out below.” now being planned or introduced for the telephone n
4、etworks either analog or digital; is in service; Edition of May 15, 1986 CEPT T/CS*54-L2*E BY m 2326434 00052LL 4 W _ TICS 54-12 E Page 3 Contents 1. OBJECTIVES OF THE MEASUREMENTS . . . . . . . , . . . , . . . . . . . . . . . . . . . 5 2. TRAFFIC TYPES, OBJECT TYPES AND ENTiTES . . . . . . . . . .
5、. . . . . . . . . . . . . 6 3. AN OVERVIEW OF DATA COLLECTION PROCESS AND MEASUREMENT ENTITIES FOR EACH OBJECT TYPE AND EACH TRAFFIC TYPE . . . . . . . . . . . . . . . . , . . . . . . 7 4. CLASSES OF MEASUREMENT , , . . , . , . . . . , . . . . . . . . . . . . . . . . . . . . 15 5. PRESENTATION OF TH
6、E RECOMMENDED SET OF MEASUREMENT TYPES . . . . . . . . . 16 6. REQUIREMENTS ON THE VARIOUS PARAMETERS. . . . . . . . . . . . . . . . . . . . . . 19 Defenitions related to tranIc measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . 20 Reference . . . . , . , . . . , . , , , , . ,
7、. . . , . . . . , . . . , . . . , . . . . . . . . . 24 Edition of May 15, 1986 CEPT T/CS*54-32*E 4 - 2326434 0005232 b m TICS 54-12 E Page 5 GENERAL, The present Recommendation deals with the definition of the various trafic measurement types for circuit switched telephony service. This Recommendati
8、on applies to digital local and transit exchanges whether these exchanges are located in a fully digital network (switching and transmission) or in a mixed analogue/digital network. The measurement types are to be considered as a set of minimum requirements for the exchange. Traffic analysis funtion
9、s performed by further processing of the result of the recommended measurment types, are not considered in the present recommendation. The trafic measurement model used in this recommendation is defined by CCITT, see the methodology Recom- mendation 2.332. All information contained in this recommend
10、ation doesnt imply any specific implementation. 1. 1.1. O 1.2. 1.3. O 1.4. 1.5. 1.6. OBJECTIVES OF THE MEASUREMENTS In the following the main objectives of the traffic measurements in the exchanges are presented from the user (administration) point of view. Exchange dimensioning and planning Dimensi
11、oning of the equipment of an exchange must be based on studies on the evolution and growth of trafic. For the recognition of possible bottlenecks or overdimensioning and the proper dimensioning of extensions or new circuit groups it is desired that e.g. the following information could be derived: -
12、busy hour traffic on the exchange consisting of the total amount of originating trafic, incoming traffic, internal subscriber trafic, transit trafic, terminating trafic and outgoing trafic. It is also necessary to measure the trafic carried by the control equipment, Le. processors, by the switching
13、stages, by the auxiliary units, etc. Network dimensioning and planning For the proper dimensioning of the routes in the telephone network it is necessary to get information of the destination traffic flows in the network and perform studies on the evolution and growth of the traffic. For the recogni
14、tion of possible bottlenecks or overdimensioning and the proper dimensioning of new circuit groups it is desired that e.g. the busy hour trafic intensity could be derived on each circuit group. In the case of bothway circuits the different categories of trafic must be treated separately. Exchange pe
15、rformance monitoring In order to maintain the network technical performances, i.e. the quality of service at the required standard levels, it is important to monitor the traffic in the exchanges continuously and undertake correct ive actions in the case of degradation. For example trafic load balanc
16、ing may be related to this monitoring. Switching systems should provide automatic measurements of trafic and grade-of-service indicators. Trafic measurements data should be divided into two categories : - data provided in real-time, for on-line survey of the grade-of-service; - data recorded, for fu
17、rther analysis of the grade-of-service and engineering purposes. Network (trascabiiity) performance monitoring Traffic analysis need information of the traffic flows in the network, in order to verify trafficability performance (grade of service) in the telephone network. Support to maintenance The
18、observation of real trafic in the exchanges provides information which can be used for the location of faults, e.g. by - providing information about the distribution of holding times and indicating devices on which the average holding time is abnormally low or high due to an eventual fault; - indica
19、ting devices that are constantly busy or free due to a possible fault. Accounting tariffs and marketing Traffic data may be needed for the division of revenues behveen different companies or and also for optimizing the tariff policy. Observation of subscriber behaviour yields information for the mar
20、keting departments. It is desired to study the characteristics of the trafic of various socio-professional subscriber categories, and to calculate short or medium term traffic forecasts by subscriber category or geographical area. Also the behaviour of the users in relation to the network should be
21、characterized. Edition of May 15, 1986 CEPT T/CS*54-32*E 84 m 2326434 0005233 m TICS 54-12 E Page 6 1.7. 1.8. 2. 2.1 Network management in real-time Network management requires real-time monitoring and measurement of the status and performance of the network, and the ability to take prompt action to
22、 control the flow of traffic when necessary, as specified in the E.410 series of CCITT Recommendations, see also Recommendations Q.506 and Q.516. Experience has shown that it is difficult to perform network management functions unless exchanges are provided with the necessary facilities to support t
23、hese functions. Traffic data are required to identify and quantify difficulties as they occur in the network to alert network managers and/or management systems that some action may be required, to measure the effect of any network management action taken, and to indicate when a network management a
24、ction should be modified or removed. Accordingly, traffic data must be collected and processed in real time and it should be based on a system of measurement, which is either continuous, or of a high sampling rate to quickly measure traffic changes and allow a rapid network management response. In t
25、he case of unexpected failure in the network it is the purpose of network management operations to prevent the propagation of congestion. The continuous supervision of the traffic situation should provide the network manager and/or systems sufficient indicators for taking appropriate actions which m
26、ay be either protective (e.g. unidirecting or blocking of routes) or expansive (e.g. rerouting). It is desired that e.g. the completion ratio of each circuit group and destination code could be derived at sufficiently small intervals. Subscriber monitoring This class of objective should help to sett
27、le problems which may occur between the subscriber and the administration; subscriber complaints may refer to billing, quality of service, etc. The subscribers monitoring is based on the results of subscribers observation”) which are presented by the exchange. These results are summaries of each cal
28、l related to the observed subscriber and containing information such as: If the call is effective or not, various time intervals including conversation time, number or metering pulses, etc. TRAFFIC TYPES, OBJECT TYPES AND ENTITIES Traffic types From the trafic measurements point of view the followin
29、g traffic types (Figure i) are identified. EXCHANGE 6 I Figure 1 (T/CS 54-12). Traffic flow types in a generalized digital exchange. 1 Originating traffic. 2 Incoming trafic. 3 Terminating trafic. 4 Outgoing traffic. 5 Internal trafic. 6 Transit trafic. 7 Incoming terminating traffic. 8 Originating
30、outgoing trafic. *) Note: Observation does not imply recording of the actual conversations. I-. Edition of May 15, 1986 2.2. 2.3. 3. O 3.1. . - CEPT T/CS*54-12*E 4 m 2326414 0005234 T m TICS 54-12 E Page 7 The following trafic types are also identified but to be studied further and are therefore not
31、 yet taken into account for the rest of this recommendation such as the call event diagrams (see 3.5.) and the recommended set of measurement types 9 Originating are system-terminating traffic. 10 Incoming are system-terminating traffic. 11 System-originating are terminating traffic. 12 System-origi
32、nating are outgoing trafic. *) The source and sink are defined with respect to trafic flows and they do not imply specific implementations for supplementary services or auxiliary units. Further study is required on how operator trafic should be defined in this model. Object types Individual items on
33、 which the measurement is performed are considered as objects. The following object types have been identified: (a) circuits, circuit groups - incoming - outgoing - both way; (b) destinations; (c) subscriber lines, subscriber line groups - single subscriber line - PABX-groups - groups of operator li
34、nes; (d) auxiliary units; (e) common control units; (f) signalling units. Entities The quantities for which data collection must be performed in a certain measurement are cailed entities. Examples of entities are (a) call based entities - no. of bids - no. of call attempts - no. of seizures - no. of
35、 successful call attempts; - traffic intensity - number of circuits in service. (b) object status based entities AN OVERVIEW OF DATA COLLECTION PROCESS AND MEASUREMENT ENTITIES FOR EACH OBJECT TYPE AND EACH TRAFFIC TYPE This chapter presents an overview of the necessary basic data for trafic measure
36、ment. This data is classified in the following in to four categories (see 3.1. to 3.4.). The list of entries of the measurement matrix provides an overview and should lead to the identification of the minimum set of entities for each object type. The object is from the MML point of view actually a d
37、elimiter which is used to control the measurement process. Thus from the traffic measurement process point of view they are not “true objects”. of the measurement. In many cases the entities of a measurement can be common to several objects of different type or even object independent (traffic type
38、dependent). Data collection Data from traffic measurements are stored in the exchange in counters. There are two basic types of counters: - counters belonging to a certain object; - counters belonging to a certain traffic type. These counters can be common to several objects of the same object type
39、or different object types. The latter ones are sometimes called “exchange counts” The object status data which is needed for the switching programs (circuit idle, subscriber busy, etc.) is also used for traffic measnrement piirposes. - Edition of May 15, 1986 TICS 54-12 E Page 8 Three distinct metho
40、ds of data collection can be distinguished (a) Data collection on cumulative counters, where data related to a particular event are summed (= event registration). Examples of event are: a bid, a seizure, internal congestion, etc. (b) Data collection by regular inspection of status (circuit busy/free
41、 states, memory allocation indicators, etc.) indicators (up/down counters). Statistical information such as traffic intensity and equipment load can be derived with the help of this data. (c) Call oriented data collection, where data related to a particular call are captured (= call reporting). A nu
42、mber of details of every nth call or calls fulflling a preselected selection criterion is recorded. The third data collection method applies a call-driven concept, whereas the first two methods apply a scan-driven concept to derive statistical data. Any equipment withdrawn from service (not-servicea
43、ble or backward blocked) is excluded from trafic measurements, but the quantities of such equipment during the periods of the measurement has to be determined. Counters and status indicators belonging to a certain object For each individual object (subscriber, circuit, route, destination, etc.) ther
44、e is a number of counters and each of them is assigned to a certain entity (e.g. number of seizures, number of successful calls, number of unsuccessful calls). All the objects of an object type have the same number of counters. 3.2. Subscribers Status data Event counters / 2-74 / / Circuits, routes,
45、 auxiliaries origins, destinations, CCS-links / L- / Figure 2 (T/CS 54-12). Object dependent counters. The number of counters per object for each type and the entities which are cumulating these counters have to be studied and should be chosen according to the object type and the needs of trafic mea
46、surements. It has to be studied if the use of some or all of these counters is depending on whether the object is in the object list of an activated measurement. 3.3. CaU record Call records contain data relevant to the call set up phase, the conversation phase and the clear-down phase. The call rec
47、ord contains information about the objects which are related to the call (A-subscriber, B- subscriber, incoming circuit, outgoing circuit, etc.) and entities which are trafic type dependent (see Figure 3). A-subscriber, B-subscriber, incoming and outgoing circuit, auxiliary unit, CCS-link RELATED EN
48、TITIES OBJECTS (Events and/or times of occurrences) Figure 3 (T/CS 54-12). Call record. -. Edition of May 15, 1986 CEPT T/CS*54-L2*E 4 = 2326414 0005236 3 W TICS 54-12 E Page 9 Information related to call records, whether assembled or not, should be made available immediately or deferred for further
49、 processing. If the contents of a call record or a part of it is stored on a mass memory it has to be studied if the objects related to the call will be used to limit the output on the mass memory. Anyhow the required trafic measurement results or other results are obtained by post processing the contents of the mass memory. Exchange counts (counters belonging to a traffic type) If the contents of a call record are to be stored to exchange counts (see Figure 4) the objects (any of them or several of them) can be used in defining the sets of counters which are
