TCP / IP protocol and application principles

A, TCP / IP model

1, TCP / IP four-layer model, five of the OSI model and model comparison

Commonly used are: TCP / IP five layer model

2, TCP / IP and OSI models the same five point seven layer model:

Both are based on the concept of stack-based

Protocol stack protocol independent of each other

The lower layer of the upper layer to provide services

3, TCP / IP and the OSI seven-layer model model five different points:

OSI is the first model, after the protocol; TCP / IP is the first protocol, after the model

Applicable to various OSI protocol stack; TCP / IP is only applicable to TCP / IP networks;

The number of different levels

Two, TCP / IP version 4 and version 6

1, TCP / IP 4 protocol

Internet protocol currently used

Applications crisis resulting from inadequate number of IP addresses

2, TCP / IP 6 protocol

Next Generation Internet Protocol

Solve the problem of insufficient number of IP addresses

Provide more efficient security, Qos functions

.. 3, TCP / IP protocol suite

1, the application layer protocol

HTTP: Hypertext Transfer Protocol

TFTP: Trivial File Transfer Protocol

SMTP: Simple Mail Transfer Protocol

SNTP: SNMP

DNS: Domain Name Service

FTP: File Transfer Protocol

2, the transport layer protocol

TCP: Transmission Control Protocol, a connection-oriented service

UDP: User Datagram Protocol, to provide service-oriented connectionless

3, the network layer protocol

ICMP: Internet Control Message Protocol

IGMP: Internet Group Management Protocol

IP: Internet Protocol

ARP: ARP

RARP: Reverse ARP

4, the data link layer, a physical layer protocol

Defined by the underlying network protocol

Fourth, data encapsulation and decapsulation

1, examples of stratified (by letter transceiver appreciated encapsulated and decapsulated)

Send and receive letters similar to the process, the writer will write a letter in an envelope and mail, local post office Lanshou, according to the post office after delivery to the recipient destination location, post office delivered to the recipient, the recipient open the envelope, View letters.

2, the encapsulation and decapsulation process data