TACACS+ (Terminal Access Controller Access Control System) differs significantly from TACACS and is also not compatible with it. Although it is also an authentication protocol, it works with a message digest function for the passwords
. TACACS+ is transmitted by the TCP protocol and supports the Password Authentication Protocol (PAP) and the Challenge Handshake Authentication Protocol
(CHAP). TACACS+ is used in user management and in network management of carrier and provider networks. Since it is based on the TCP protocol, transmission errors such as packet loss or timeouts are corrected. Furthermore, with TACACS+ all information is encrypted: the password, the user name, the authorization and the user account; and not as with the Radius protocol, where only the password is transmitted in encrypted form.