In computer networking, the Network Access Identifier (NAI) is a standard way of identifying users who request access to a network. The standard syntax is "user@realm". Sample NAIs include (from RFC 4282): bob joe@example.com fred@foo-9.example.com fred.smith@example.com fred_smith@example.com fred$@example.com fred=?#$&*+-/^smith@example.com eng.example.net!nancy@example.net eng%nancy@example.net @privatecorp.example.net \(user\)@example.net alice@xn--tmonesimerkki-bfbb.example.net Network Access Identifiers were originally defined in RFC 2486, which was superseded by RFC 4282, which has been superseded by RFC 7542. The latter RFC is the current standard for the NAI. NAIs are commonly found as user identifiers in the RADIUS and Diameter network access protocols and the EAP authentication protocol. See also Diameter EAP RADIUS Request for Comments The Network Access Identifier (NAI) is the user identity submitted by the client during network access authentication. It is used mainly for two purposes: The NAI is used when roaming, to identify the user. To assist in the routing of the authentication request to the user's authentication server. External links RFC 7542 RFC 4282 Internet Standards