International Telecommunication Union   ITU
عربي  |  中文  |  Espa˝ol  |  Franšais  |  Русский
 Advanced Search Advanced Search Site Map Contact us Print Version
Home : ITU-T Home : Study Groups : ITU-T Study Group 12
Question 12/12 – Operational aspects of telecommunication network service quality
(Continuation of Q.4/2)


It is essential to specify network service quality parameters to enable telecommunication services to be offered to customers/users in order to satisfy customers’/users’ quality of service expectations. These parameters relate to both implementation and ongoing use of the service. Service quality is also related to all aspects of network assessment and management.

Standardization of service quality parameters and measures are needed for all services using current networks and Next Generation Networks (NGN).

The following Recommendations/ Supplements/Handbooks, in force at the time of approval of this Question, fall under its responsibility:

E.420-E.479, E.800-E.859



  1. That service quality of networks needs to be assessed as a total connection, focusing on the end-to-end network service offered at all times;
  2. that there is a need to support service assessments by measurement of clearly defined service and network parameters;
  3. that service quality parameters are required in order to meet customers’/users’ expectation of a service, and related network performance parameters should relate to service quality parameters;
  4. that emerging customer/user applications on Next Generation Networks (NGN) have the need for high-quality and seamless interworking;
  5. that network providers must plan, dimension and operate their networks to parameters which will ensure that services offered to customers/users meet the latter’s quality of service expectations;
  6. that increasingly operational and QoS aspects of security recommendations must be considered;
  7. that some alternative calling procedure may reduce significantly the service quality of networks;
  8. that customers/users expect distinct quality of service classes;
  9. that customer/user behavior associated with a service could have an impact on network performance and quality of service;
  10. that voice and other services will be offered on emerging network and access technologies;
  11. that advanced routing methods will have an impact on how parameters are measured.

What new or revised Recommendations are required to ensure that adequate network service quality can be provided to meet customers’/users’ expectations?

For example, new recommendations may be required for the emerging Next Generation Networks (NGN).


New and revised Recommendations are expected during the Study Period as reflected in the table below, which will be updated on an on-going basis.

Area Priority
IP-based networks High
NGN Medium
Mobile Medium

An up-to-date status of work under this Question is contained in the SG 12 Work Programme



Within Study Group 12

  • QSDG (Quality of Service Development Group)

Within ITU-T

  • ITU-T SG2 – SNOg (Service and Networks Operations group)
  • QoS and Network Performance outside of this Question
  • Next Generation Networks
  • Signaling
  • Network Security

With other groups

  • IETF (Internet Engineering Task Force)
  • ETSI (European Telecommunications Standard Institute)
  • ATIS (Alliance for Telecommunications Industry Solutions)
  • TMF (TeleManagement Forum)


Top - Feedback - Contact Us -  Copyright ę ITU 2009 All Rights Reserved
Contact for this page : TSB EDH
Updated : 2009-01-12