Point to Point Protocol (PPP)

The PPP is useful in creating a direct link between two redistribution points. Two routers can be connected without involving any networking device or a host. Most of the physical networks utilize this type of protocol in transmitting packet data between two nodes.

They include a phone line, serial cable and radio links. It has also been useful to most of the internet service providers (ISPs) for providing customer access to the internet through dial-up processes.

It used as a data link layer in various models for establishing connection on the contemporary and asynchronous circuits. The PPP establishes a linkage between the ISP and a computer device by use of a Link Control Protocol (LCP). The LCP determines the acceptability of the link in transmission of the data. An exchange of the LCP packets occurs between several point networks to familiarize with the features of the links. These include configuration errors, packet size and device identity.

The Password Authentication Protocol (PAP) is an active tool in providing verification to the password of a user on network access server. A request is then sent to the recipient machine which provides a response that proves the verification.

The only downside with PAP is that it does not guarantee any encryption during the transmission. Another user authentication protocol of the PPP is the Challenge Handshake Authentication Protocol (CHAP). It has more features when compared to PAP. It transmits the challenge information to the client device instead of requesting a password.

The message is usually of a random value and is usually encrypted by the client machine using the credentials of the user.

The challenge and password combination are forwarded by the access server. The challenge is stored in the in the verification base after being encrypted by the password of the user. In situations where they tend to be similar, authenticity of the password is approved to be positive. The user in CHAP is authenticated by utilizing the user password, a shared model secret. It is one of the secure procedures of verification unlike the point to point protocol.

Another user authentication rule is the Extensible Authentication Protocol (EAP) and is a reliable authentication structure applicable to a variety of secure authentication protocols. It is common in verification of wireless networks. The data link layers which can be used to enclose the PPP include the Asynchronous Transfer Mode (PPPoA) and Ethernet (PPPoE).