Well-known communication protocols

There is a large number of communication protocols that operate under the TCP/IP protocol suite. Each one performs the task that it is assigned with. In the following sections, we will get to know some of them:

• Hypertext Transfer Protocol (HTTP): It is the protocol used by the browser that carries the Hypertext Markup Language (HTML) from the server to the client. It operates based on the request-response method to access websites.
• File Transfer Protocol (FTP): It is the protocol tasked to carry files from the source computer to the destination computer.
• Trivial File Transfer Protocol (TFTP): Unlike FTP, it is a connectionless simple file transfer protocol that utilizes less overhead.
• Simple Mail Transfer Protocol (SMTP): It is tasked with the responsibility of sending and receiving email from mail server.
• Post Office Protocol (POP): It is the protocol used by the email client to retrieve emails from the mail server.
• Internet Message Access Protocol (IMAP): Like POP, IMAP is used by an email app to retrieve emails from the server, however it leaves copies of emails in the mail server too.
• Domain Name System (DNS): Its responsibility is to locate and translate domain names into IP addresses.
• Dynamic Host Configuration Protocol (DHCP): It is tasked with the responsibility of dynamically assigning IP addresses to computers in a network.
• Secure Socket Layer (SSL): It is tasked with enabling a secure channel for data transmission between devices.
• Transport Layer Security (TLS): It is a successor to SSL, and provides privacy and data integrity for data transmission between devices.
• Telnet: It is a legacy method that enables administrators to access devices on remote locations.
• Secure Shell (SSH): It is more secure than Telnet, and it enables administrators to access remote devices in a secure way.
• Point-to-Point Tunneling Protocol (PPTP): It is among the first protocols used for Virtual Private Network (VPN) implementations with low security.
• Layer 2 Tunneling Protocol (L2TP): It is tasked to extend the functionalities of PPTP by increasing the security of the VPN operation over the internet.
• Transmission Control protocol (TCP): It is a connection-oriented protocol that provides reliable and orderly data transmissions. Error checking of the transmitted data is also included.
• User Datagram Protocol (UDP): It is a connectionless protocol that does the best effort in data transmission.
• Internet Protocol (IP): It is a connectionless protocol tasked to forward packets from the source computer to the destination computer.
• Network Address Translation (NAT): It is responsible for translating private IP addresses into public IP addresses thus enabling a connection to the internet.
• Routing Information Protocol (RIP): It is among the first routing protocols tasked to enable communications between routers by sharing the network topology through the utilization of the distance-vector algorithm.
• Open Shortest Path First (OSPF): It is a routing protocol that uses the link-state routing (LSR) algorithm to enable the communication between routers by finding the best path.
• Interior Gateway Routing Protocol (IGRP): It is a Cisco proprietary routing protocol that employs the distance-vector algorithm to enable communication between routers by exchanging routing information within an autonomous system.
• Enhanced Interior Gateway Routing Protocol (EIGRP): As a successor to IGRP, it is an advanced routing protocol that enables communication between routers by merging the best features from both distance-vector and link-state routing protocols. It is only used in networks with all Cisco networking devices.
• Internet Control Message Protocol (ICMP): It is the protocol used by the active devices in the network to send error messages in order to determine the availability of the service or destination device.
• Address Resolution Protocol (ARP): It is tasked to identify the physical address of a given IP address (that is, a logical address).
• Reverse Address Resolution Protocol (RARP): It is tasked to do the opposite of the ARP by identifying the IP address of a given physical address.
• Multiprotocol Label Switching (MPLS): It is a protocol that operates in between OSI Layer 2 and Layer 3 to enable high performance by forwarding data using labels.
• Spanning Tree Protocol (STP): It is tasked with the responsibility of preventing bridging loops on LANs.
• Link Layer Discovery Protocol (LLDP): It enables network devices to advertise identity, capabilities, and neighbors on LANs.
• Point-to-Point Protocol (PPP): It is tasked with the responsibility of enabling a direct connection between two devices.
• Neighbor Discovery Protocol (NDP): It replaces ARP in IPv6, and thus along with ICMP determines the physical address, reachability, and tracking of neighboring devices.
• IEEE 802.2: This standard is responsible for describing the activities of the Logical Link Control (LLC) sublayer of the OSI Layer 2.
• IEEE 802.3: This standard is responsible for specifying the physical medium and to describe the characteristics of the Ethernet in LANs.
• IEEE 802.5: This standard is responsible for specifying a token-passing communication technology in LANs.
• IEEE 802.11: This standard specifies the requirements for the implementation of the Wireless Local Area Networks (WLANs).