link control protocol (PPP) (LCP)

The Link Control Protocol(LCP) is a protocol for establishing and terminating point-to-point connections using the Point-to-Point Protocol( PPP).

In addition, the LCP protocol supports the configuration and testing of PPP connections. For prior configuration, the two connected stations send LCP data packets on the transmission line. The whole process runs in four operational phases: Link Dead, Link Established, Authentication of the Network Layer Protocol Configration and the Link Termination for the connection termination. The data format of the LCP protocol consists of the data fields Code (8 bits), Identifier (8 bits), Length (16 bits) and Data. The Code field defines the LCP information such as Configure, Terminate, Reject, Request and Reply. The 2 bytelength field, Total Length, defines the total length of the LCP data packet.

The Link Control Protocol was developed by the Internet Engineering Task Force( IETF) and is described under RFC 1570.