TCP/IP protocol family

1. the TCP (Transmission Control Protocol)/IP (Internet Protocol) protocol family is a network communication model and an entire network transmission protocol family. It is the basic communication architecture of the Internet.

TCP/IP layer-4 ProtocolIs as follows:

 

2. TCP/IP Reference Model ing to OSI model:

3. OSI model (Open System Interconnection)

OSIThe layer-7 Reference Model follows the following principles:
1. Each network node on the same layer has the same hierarchy and has the same functions.
2. interfaces (logical interfaces) are used to communicate with adjacent layers of the same node.
3. Each layer in the layer-7 structure uses the services provided by the next layer and provides services to the upper layer.
4. Communication between peer layers is achieved at the same layer of different nodes according to the protocol.

Application Layer)

The application layer provides interfaces for operating systems or network applications to access network services. Application layer protocols include telnet, FTP, HTTP, and SNMP.

Common application layer protocols include:

Protocol running on TCP:

• HTTP (Hypertext Transfer Protocol) is mainly used for common browsing.
• HTTPS (Hypertext Transfer Protocol over Secure Socket Layer, or HTTP over SSL, Secure Hypertext Transfer Protocol), secure version of HTTP protocol.
• FTP (file transfer protocol, file transfer protocol), known as, is used for file transfer.
• POP3 (Post Office Protocol, version 3, Post Office Protocol), used for receiving emails.
• SMTP (Simple Mail Transfer Protocol) is used to send emails.
• Telnet (teletype over the network, network telex), through a terminal (terminal) login to the network.
• SSH (Secure Shell, used to replace Telnet with poor security) for encrypted secure login.

Protocol running on UDP:

• BOOTP (Boot Protocol) is applied to diskless devices.
• NTP (Network Time Protocol) is used for network synchronization.

Others:

• DNS (Domain Name Service) is used for address search and Email Forwarding (running on TCP and UDP protocols ).
• Echo (echo Protocol) is used to identify errors and measure the response time (running on TCP and UDP protocols ).
• SNMP (Simple Network Management Protocol) is used to collect network information and manage networks.
• DHCP (Dynamic Host Configuration Protocol) and dynamic IP Address Configuration.
• ARP (Address Resolution Protocol) is used to dynamically resolve the IP address of the Ethernet hardware.

 

Presentation Layer)

This layer mainly solves the problem of supporting the syntax expression of information. It converts the data to be exchanged from an abstract syntax suitable for a user to a transfer syntax suitable for internal use within the OSI system. It provides formatted data representation and Conversion Services. The presentation layer is responsible for data compression, decompression, encryption, and decryption.

Session Layer)

The Session Layer does not participate in specific transmission. It provides a mechanism to establish and maintain communications between applications, including access authentication and session management. For example, the Session Layer completes the authentication of user logon on the server.

Transport Layer)

The data unit at Layer 3 is also called packets ). The transport layer is used to control data traffic and debug and handle errors to ensure smooth communication. The transmission layer of the sender adds serial numbers to the group to facilitate the receiver to reorganize the group into useful data or files.

 

Network Layer)

The two computers that communicate in the computer network may go through many data links or through many communication subnets. The task at the network layer is to select an appropriate inter-network route and exchange node to ensure timely data transmission. The Network Layer encapsulates the frames provided by the data link layer into a data packet. The packet contains a network packet header, which contains the logical address information-the network address of the source site and the destination site. Routers work on this layer, and the network becomes interconnected by constantly receiving and transmitting data.

Data Link Layer)

The role of this layer includes physical address addressing, data frame formation, traffic control, data error detection, and re-transmission. At this layer, the unit of data is frame ). Data link layer protocols include SDLC, HDLc, PPP, STP, and frame relay. Device: bridge adapter switch Switch

Physical Layer)

Specifies the mechanical, electrical, functional, and process characteristics of communication equipment for establishing, maintaining, and removing physical link connections. Specifically, the mechanical characteristics specify the specifications, sizes, number of pins, and arrangement of connectors required for network connection. Electrical Characteristics specify the line used to transmit bit streams over physical connections.

 

TCP/IP protocol family