TCP is a reliable transport layer protocol that can replace network layer reliability services. The most common backup layer protocols are listed here with a brief description. Note that most of these data link protocols are used for WAN and modem connections. LLC is a LAN data link protocol.
Examples of data connection protocols are Ethernet for local networks (multi-node), point-to-point protocol (PPP), HDLC and ADCCP for point-to-point (dual node) connections.
Data Link Address The physical or Layer 2 data link address has a different role. The purpose of the data link address is to provide the data link frame from one network interface to another network interface on the same network.
Defining the data link layer The data link layer is the second layer of the seven-layer Open Systems Interconnection (OSI) reference model. The data link layer is also responsible for logical connection control, media access control, hardware addressing, error detection and handling, as well as standard setting of the physical layer.
The units used in each level are….
- Physical layer or lower: hub, repeater, cable, optical fiber, wireless.
- Security levels: bridge, modem, network card, 2-level switch.
- Network team: router, brouter, 3 team switches.
- Transport layer: gateway, firewall.
- Session levels: gateway, firewall, PC.
Compared to other network suites
DHCP Layer 2 / Layer 3. DHCP is an application layer protocol, so IP is involved in DHCP.
Under OSI stack conditions, DNS corresponds to HTTP in the application layer (layer 7). DNS is actually a program called to help HTTP program and therefore is not under HTTP in the OSI stack. DNS itself also uses UDP and less often TCP, both of which use IP.
The best-known example of the transport layer is the Transmission Control Protocol (TCP), which is based on the Internet Protocol (IP), also known as TCP / IP. TCP and UDP port numbers work on layer 4, while IP addresses work on layer 3, the network layer.
Most of the link layer is implemented in a network card, also known as a network card (NIC).
File Transfer Protocol (FTP) is an application-level protocol that moves files between local and remote file systems. It works over TCP, like HTTP. To transfer a file, FTP uses two parallel TCP connections: a control connection and a data connection.
Someone said that HTTP is in the session layer in the OSI model. But in Tanenbaum’s computer network, HTTP would be in the application layer of the OSI model.
A: Protects the higher-level protocol from knowledge of the physical media to be used in communication.
Two types of data link devices are commonly used in networks: bridges and switches. A bridge is an intelligent repeater that knows the MAC addresses of the nodes on both sides of the bridge and can forward packets accordingly.
Data link protocol. In networking and communication, the transmission of a data device (frame, packet) from one node to another. The data link protocol is known as a layer 2 protocol and ensures that the bits and bytes received match the bits and bytes sent.
The data link layer protocols are Ethernet, Token Ring, FDDI, and PPP. An important feature of a data link layer is that the datagram can be processed by different protocols of the data link layer over different parts of a path. For example, the datagram is managed via Ethernet on the first link and PPP on the second link.
The transport layer is the fourth layer of the TCP / IP model that deals with logical communication between processes. It is responsible for delivering messages between the network host. It also accepts data from the application layer and prepares it for addressing at the network layer.
The network layer is the third layer of the Open Systems Interconnection (OSI) model and the layer that provides data routing paths for network communication. The data is sent as packets over logical network paths in an ordered format managed by the network layer.