Summary

Recommendation ITU-T Y.1545 is intended as a guide to help regulators and network service providers meet QoS performance objectives.

Traditional packet networks have been built under the principle that networks will operate on the basis of an unguaranteed best‑effort packet delivery. The best effort paradigm has been spectacularly successful in supporting non-real-time data applications (e.g., email and file transfer); this principle assigns the responsibility for detecting and correcting transmission problems to the customer equipment and higher-level protocols that require better network support.

However, the best-effort delivery principle does not provide a reliable quality of user experience in interactive voice telephony and other demanding real-time applications when network bandwidth limitations increase considerably delay, jitter and packet loss. These applications work best across networks that can deliver "better than best-effort" performance for various characteristics.

This corrigendum introduces changes related to the withdrawal of IEEE 802.1D.