ETSI ES 202 765-2 aims at identifying and defining indicators and methodologies for a use in a context of end-user quality characterization and supervision of voice telephony services.

In this context the measurements and metric determinations are performed by analysing signals accessible on user-end services and not on the network. In order to mirror the reality in terms of access to the services at the user-end, measurements and analyses are performed on electrical signals by excluding the electro-acoustic part of the end equipment, however the probe adaptation to the electric interface of the end user equipment takes into account the electro-acoustic characteristics of this terminal.

All the indicators presented and defined in the present document are objective indicators obtained by instrumental measurement methods.