What network devices correspond to the transport layer in the OSI model

In the OSI seven-layer model, the transport layer uses port numbers to distinguish different application processes.

In applications such as ACLs of routers, different services can be filtered according to the port number, so the router should be one of the devices with transport layer functions;

In the same way, many applications of firewalls can also handle port numbers, so firewalls should be one of the devices with transport layer functions;

It is also possible to process port numbers in gateways and hosts, so it can also be considered that these devices also have the function of the transport layer.

Layer 1 device: Hub, no operating system.

Layer 2 device: switch, operating system: iOS

Layer 3 device: router, operating system: iOS

Layer 4 device: ordinary computer, operating system: XP Win7 Linux...

In fact, routers can also customize the system themselves.

Computers...It's the application layer! Its versatility determines its application! The linked devices are all at the physical layer!!

Because these are just processing analog signals and digital signals (repeaters, hubs, etc.), these are the physical layer!! The link layer is the one that handles data such as switches, bridges, gateways, etc.! Layer 3 is the network layer, which is related to IP packets, routers....Layer 3 switches, etc....There are no clear examples of devices above the transport layer!!

Hope it helps....

The so-called layer of equipment refers to the highest level of functions that this device can achieve, and the reason why the router is a layer 3 is because it can implement the layer 3 protocol, while the higher layer does not have this function.

Although the OSI model has 7 layers, this reference model is too complex, so no commercial protocol really implements it exactly, that is, it simplifies it. Therefore, many layers of equipment do not exist.

The functions of these layers are realized through software, that is, it can be said that the functions of the network software running on your computer belong to this layer, but it cannot be said that the computer belongs to this layer.

Generally speaking, the functions above the third layer are implemented in software, and there are no hardware devices to correspond to them.

The computer can't be said to belong to which layer, the layer 3 switch.

The data is sent from your own computer to the other party's computer through the application layer, the presentation layer, the session layer, the transmission layer, the network layer, the data link layer, and reaches the final physical layer, and then converted into a bit stream, and finally transmitted to the other party's computer through a certain transmission medium, such as twisted pair, coaxial cable, and optical fiber. When it reaches the physical layer of the other computer, it also uploads the application layer by layer.

At the physical layer of the OSI RM protocol model, the basic unit of data transmission is the bit (Bitstream

Application layer application software such as QQ, with discourse, presentation layer (select transmission encoding), session layer (establishment terminal at the end of the Dragon Boat Festival), transmission layer (what transmission is used, such as QQ), network layer.

IP data transmission path), data link layer.

On the basis of the network layer, the MAC address is encapsulated, the exact address), and the physical layer (for raw bitstream transmission).

Peer-to-peer layer and peer-to-peer protocol:

The same layer between different hosts is called a peer layer. The application layer of host A and the application layer of host B are peer layers to each other, and the session layer of host A and the session closed layer of host B are peer layers to each other.

There is an agreement relationship between peer tiers. That is, peers need to abide by certain rules when communicating with each other, such as the content of communication and the square car of communication. The rules that must be followed when exchanging data or communication between such peer entities are called peer protocols.

In addition to the physical layer, the OSI model.

The other 6 peering layers in all exist with corresponding protocols.

In the OSI reference model,Physical layerThe transmission is:Bitstream

The physical layer is an OSI reference model.

It uses the transmission medium to establish, manage, and release physical connections between the hosts of communication, so as to realize the transparent transmission of the bit stream (the transmission unit is bits), and ensure the correct transmission of the bit stream through the transmission medium.

The physical layer shields the transmission medium used by the physical layer, the difference between communication equipment and communication technology, and specifies different types of physical protocols, so that the data link only needs to consider how to use the services of the physical layer, regardless of the transmission medium used by the physical layer.

Physical Layer Regulations:

Mechanical, electronic, functional, and regulatory characteristics are provided for creating, maintaining, and dismantling the physical links required to transmit data. Put simply, the physical layer ensures that the raw data can be transmitted over a variety of physical platforms. Local area network.

and the WAN are both Layer 1.

The physical layer is the first layer of OSI, and although it is at the lowest level, it is the foundation of the entire open system. The physical layer provides core-transmitter and interconnect devices for data communication between devices, providing a reliable environment for data transmission. If you want to remember this first layer in as few words as possible, it's "signal and medium".

The above content refers to: Encyclopedia-OSI physical layer.