|  |  | Terminal Access Control Access System +, or TACACS+, accepts a request from a TACACS client and passes the information to a TACACS server for authentication, using encrypted TCP/IP as the communication protocol. TACACS+ supports callback. Callback prevents a hacker posing as an authorized user from connecting at a different location. It saves the remote user long-distance charges. TACACS+ supports Triple A systems, PAP, and CHAP.