This Recommendation specifies network (UNI-UNI) IP performance values for each of the performance parameters defined in [ITU-T Y.1540]. The specific performance values vary, depending on the network QoS class. This Recommendation defines eight network QoS classes, two of which are provisional. This Recommendation applies to international IP network paths (UNI-UNI). The network QoS classes defined here are intended to be the basis of agreements between end-users and network service providers, and between service providers. The classes should continue to be used when static agreements give way to dynamic requests supported by QoS specification protocols.
ITU-T Y.1541-2011 history
2011ITU-T Y.1541-2011 Network performance objectives for IP-based services Study Group 12