OSI seven-layer detailed three network layer

First, Introduction

There may be many data links between the two computers that communicate in the computer network, or they may go through many communication subnets. The task of the network layer is to select the appropriate inter-network routing and switching nodes to ensure the timely transmission of data. The network layer consists of a packet of frames provided by the data link layer, which is encapsulated in a network layer header, which contains a logically

Site information-the network address of the source and destination site addresses.

If you're talking about an IP address, then you're dealing with layer 3rd, which is the "packet" problem, not the 2nd "frame". IP is part of the 3rd tier problem, and there are routing protocols and address resolution protocols (ARP). Everything about routing is handled on the 3rd level. Address resolution and routing are important purposes of layer 3. The network layer can also

It realizes congestion control, Internet interconnection and other functions.

At this level, the unit of data is called a packet (packet).

Representatives of the Network layer protocol include:

IP, IPX, RIP, OSPF, and more.

Network Layer main functions:

The network layer provides the following key features for establishing network connectivity and servicing the upper layers:

Route selection and Trunking

Activate, terminate network connection

Multiplexing multiple network connections on a single data link and taking time-sharing multiplexing techniques

Error detection and recovery

Sequencing, Flow control

Service Selection

Network management

Network Layer Main equipment:

Router.

Product Representative:

Tp-link tl-r4148.

Second, the data format

OSI seven-layer detailed three network layer