As stated in [ITU-T Y.1271], enhanced priority treatment is an essential requirement for the assured
capabilities needed for emergency telecommunications. One critical component is admission
control and associated priorities as described in [ITU-T Y.2171]. Another critical component is
service restoration particularly during emergency conditions with potentially reduced network
bandwidth/resources. Under such conditions, emergency telecommunications interrupted by
network failures require preferential restoration treatment. In the NGN, assured restoration can be
enabled by:
1) development of service restoration priority levels based on the criticality of services;
2) development of the necessary extensions in signalling protocols that can indicate the
restoration priority levels during call/session set-up;
3) development of restoration mechanisms that can recognize the signalled priority levels and
undertake the necessary restoration/re-routing action.
The scope of this Recommendation is limited to the development of priority levels for service
restoration in the NGN. This guidance can be helpful in the development of the subsequent
signalling extensions and restoration mechanisms.
Administrations may require operators and service providers to take into account national
regulatory and national policy requirements in implementing this Recommendation.
ITU-T Y.2172-2007 Referenced Document
ITU-T E.361-2003 QoS routing support for interworking of QoS service classes across routing technologies Study Group 2
ITU-T Y.1271-2004 Framework(s) on network requirements and capabilities to support emergency telecommunications over evolving circuit-switched and packet-switched networks SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS In*， 2024-04-18 Update
ITU-T Y.1291-2004 An architectural framework for support of Quality of Service in packet networks SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE INTERNET PROTOCOL ASPECTS AND NEXT GENERATION NETWORKS Internet protocol aspects Architecture access network capabilities and resou
ITU-T Y.2171-2006 Admission control priority levels in Next Generation Networks Study Group 13
ITU-T Y.2172-2007 history
2007ITU-T Y.2172-2007 Service restoration priority levels in Next Generation Neworks Study Group 13