Networking Protocols: CSMA/CD, VTP, FTP, HDLC & More
Networking Protocols Explained
CSMA/CD (Carrier Sense Multiple Access with Collision Detection)
Carrier Sense Multiple Access with Collision Detection (CSMA/CD) is a network protocol for carrier transmission that operates in the Medium Access Control (MAC) layer. It senses or listens to whether the shared channel for transmission is busy or not, and defers transmissions until the channel is free. The collision detection technology detects collisions by sensing transmissions from other stations.
VTP (Virtual Terminal Protocol)
Virtual Terminal Protocol allows a PC to connect to a remote server, usually to perform a file transfer or run an application. In the past, this functionality used to be performed by a physical terminal, but is now emulated in software. The PC and the server may be running different operating systems but can communicate using well-known network protocols such as Telnet, SSH, FTP, etc.
FTP (File Transfer Protocol)
FTP stands for File Transfer Protocol. It is a standard internet protocol provided by TCP/IP used for transmitting files from one host to another.
- It is mainly used for transferring web page files from their creator to the computer that acts as a server for other computers on the internet.
- It is also used for downloading files to a computer from other servers.
HDLC (High-Level Data Link Control)
High-Level Data Link Control (HDLC) is a group of communication protocols of the data link layer for transmitting data between network points or nodes. Since it is a data link protocol, data is organized into frames. A frame is transmitted via the network to the destination that verifies its successful arrival. It is a bit-oriented protocol that is applicable for both point-to-point and multipoint communications.
Electronic Mail (Email)
Electronic mail is one of the most well-known network services. Electronic mail is a computer-based service that allows users to communicate with one another by exchanging messages. Email information is transmitted via email servers and uses a variety of TCP/IP protocols. For example, the Simple Mail Transfer Protocol (SMTP) is a protocol that is used to send messages. Similarly, IMAP or POP receives messages from a mail server.
Sliding Window
The sliding window is a technique for sending multiple frames at a time. It controls the data packets between the two devices where reliable and gradual delivery of data frames is needed. It is also used in TCP (Transmission Control Protocol). In this technique, each frame is sent with a sequence number. The sequence numbers are used to find the missing data at the receiver end.
HUB
A hub is a physical layer networking device which is used to connect multiple devices in a network. They are generally used to connect computers in a LAN. A hub has many ports in it. A computer which intends to be connected to the network is plugged into one of these ports. When a data frame arrives at a port, it is broadcast to every other port, without considering whether it is destined for a particular destination or not.
Star and Bus Topologies
Star Topology: In Star Topology, all the devices are connected to a single hub through a cable. This hub is the central node, and all other nodes are connected to the central node. The hub can be passive in nature (i.e., not an intelligent hub such as broadcasting devices), or the hub can be intelligent, known as an active hub.
Bus Topology: Bus Topology is a network type in which every computer and network device is connected to a single cable. It is bi-directional. It is a multi-point connection and a non-robust topology because if the backbone fails, the topology crashes.