PPP Contract Structure (upstream) and Introduction to Payment Mechanism Introduction to the Basic PPP Project Structure When to Use PPPs: Motivations and Caveats Where PPPs are Used – Infrastructure Sectors Private Participation in Public Infrastructure and Services: What is and is not a PPP The receiver on receiving the message removes the escape byte before passing it onto the network layer. The escape byte, 01111101, is stuffed before every byte that contains the same byte as the flag byte or the escape byte.
#A ppp frame includes a fcs which is code
The standard code used is CRC (cyclic redundancy code)īyte Stuffing in PPP Frame − Byte stuffing is used is PPP payload field whenever the flag sequence appears in the message, so that the receiver does not consider it as the end of the frame. However, this may be negotiated between the endpoints of communication.įCS − It is a 2 byte or 4 bytes frame check sequence for error detection. The maximum length of the payload field is 1500 bytes. Payload − This carries the data from the network layer. Protocol − 1 or 2 bytes that define the type of data contained in the payload field. The bit pattern of the flag is 01111110.Īddress − 1 byte which is set to 11111111 in case of broadcast.Ĭontrol − 1 byte set to a constant value of 11000000. The fields of a PPP frame are −įlag − 1 byte that marks the beginning and the end of the frame. PPP is a byte - oriented protocol where each field of the frame is composed of one or more bytes. Internetwork Packet Exchange Control Protocol (IPXCP) OSI Network Layer Control Protocol (OSINLCP)
Internet Protocol Control Protocol (IPCP) For every higher-layer protocol supported by PPP, one NCP is there. Network Control Protocols (NCPs) − These protocols are used for negotiating the parameters and facilities for the network layer. The two authentication protocols of PPP are −Ĭhallenge Handshake Authentication Protocol (CHAP) It also imparts negotiation for set up of options and use of features by the two endpoints of the links.Īuthentication Protocols (AP) − These protocols authenticate endpoints for use of services. Link Control Protocol (LCP) − It is responsible for establishing, configuring, testing, maintaining and terminating links for transmission. Point - to - Point Protocol is a layered protocol having three components −Įncapsulation Component − It encapsulates the datagram so that it can be transmitted over the specified physical layer. Supporting a variety of network layer protocols by providing a range os services. Providing connections over multiple links. Providing address for network communication. Stating authentication rules of the communicating devices. Stating the method of encapsulation of network layer data in the frame. The main services provided by Point - to - Point Protocol are −ĭefining the frame format of the data to be transmitted.ĭefining the procedure of establishing link between two points and exchange of data. Since it is a data link layer protocol, data is transmitted in frames. It is a byte - oriented protocol that is widely used in broadband communications having heavy loads and high speeds. Point - to - Point Protocol (PPP) is a communication protocol of the data link layer that is used to transmit multiprotocol data between two directly connected (point-to-point) computers.