Hello. Sign In
Standards Store

ITU-T Q.544

1988 Edition, November 1, 1988

Complete Document


Detail Summary

Active, Most Current

Price (USD)
Single User
In Stock
PDF + Print
In Stock
$35.70 You save 30%
Add to Cart

Product Details:

Description / Abstract:


This Recommendation applies to digital local, combined, transit and international exchanges for telephony in Integrated Digital Networks (IDN) and mixed (analogue/digital) networks, and also to local, combined, transit and international exchanges in an Integrated Digital Networks (ISDN). The field of application of this Recommendation is more fully defined in Recommendation Q.500. Some measurements only apply to a certain type (or types) of exchange. Where this occurs, the application is defined in the text. Where no such qualification is made, the measurement applies to all exchange applications.

This Recommendation includes traffic and performance measurements that are necessary for provisioning and operating exchanges so as to satisfy grade of service objectives covered in the E.500 series of Recommendations. These measurements are typically performed during specified periods and intervals after which the results are sent to designated local and/or remote exchange terminals or operation and maintenance centres (OMC) or any other appropriate data handling centre. In some cases, data may be utilized in its original form whereas in other cases data may need to be processed to determine when pre-set thresholds are exceeded and/or to recognize an abnormal condition when it occurs. In this Recommendation, no particular system design requirement is implied. Different designs may have more or less data accumulated and processed within the exchange or by an external system.

Different types and sizes of exchanges may require different sets of measurements. Also, different Administrations may have different requirements for measurements depending on policies, procedures or national network considerations. An Administration may thus find it desirable in some applications to measure items that are not covered by this Recommendation whereas in other applications some measurements may not be desired.

Exchange measurements are required for both national and international service. Requirements for international service take into consideration the following CCITT Recommendations:

– Recommendations E.401 to E.427: International telephone network management and checking of service quality;

– Recommendations E.230 to E.277: Operational provisions relating to charging and accounting in the international telephone service.

The aspects of traffic engineering are given in Recommendations E.500 to E.543. Recommendations on traffic measurements for SPC exchanges are provided by Recommendations E.502, E.503 and E.504.

Additional measurements in an exchange, not specified in this Recommendation, are required, e.g. for:

– Transmission performance (Recommendations Q.551, Q.552, Q.553 and Q.554).

– Digital access signalling (Recommendations Q.920 to Q.931). This is for further study. – Packet mode (Recommendations X.25 and X.75). This is for further study.

– Signalling System No. 7 (e.g. those measurements specified in Recommendation Q.791 for the message transfer part require further study to determine their applicability to this Recommendation).

Note – For the terms and definitions of teletraffic used in this Recommendation, see Recommendation E.60