Reservation precedes possible assignment.
It can also identify the called party, or the ETNS SP or the originating network for routing purposes. A SgN, contrary to an Assisted Network, can analyse the whole EN through a database dip. In case ITU decides not to assign a global resource to the ETNS, the ETNS conventions are not applicable. General Management of the ETNS shall follow the principles of transparency, objectivity, non-discrimination and proportionality, established for the 1998 EU telecommunication liberalisation. The EN has a maximum length of fifteen digits.