Title: 1.6 Protocols
Course: Information and Communication Technology: Module B > Section: Section 1 - Telecommunications and Network Basics

1.6.1 Protocols

Protocols, also known as standards, are a set of rules that govern how devices and components interact with each other. Protocols are essential parts of many modern technologies. They are consensus-based documents that describe specific details for vendors, manufacturers, and other stakeholders to follow in order to ensure interoperability.

Adopting standard protocols has benefits in all aspects of technology. Whether you need to repair, replace, upgrade, or build new networking equipment, you are assured network compatibility.

There are three network protocols that have emerged as de facto standards for local networks:

- Ethernet over twisted pair or IEEE 802.3 is the accepted standard for wired and wireless networking. The IEEE 802.3 standard specifies that a network implements the Carrier Sense Multiple Access with Collision Detection (CSMA/CD) access control method.

- WiFi or 802.11a/b/g/n/ac is the accepted standard for wireless networks.

- The TCP/IP protocol stack has been the Internet standard since 1983 and is a component of all modern networks.

1.6.2 Protocols

TCP/IP is used to exchange information on the Internet. It contains a combination of many protocols:

- Ping is a command that tests for connectivity. Ping works by sending an ICMP echo request to the destination computer. The receiving computer then sends back an ICMP echo reply message.

- Tracert is a utility that displays the route a packet takes on its journey from source computer to destination host.

- Address Resolution Protocol (ARP) is the means by which networked computers map Internet Protocol (IP) addresses to physical hardware (MAC) addresses that are recognized in a local network. The ARP cache is the means by which a correlation is maintained between each MAC address and its corresponding IP address.

- Reverse Address Resolution Protocol (RARP) is a protocol used to obtain IP address information based on the physical or MAC address. RARP provides the rules by which the physical machine in a LAN can request to learn its IP address from a gateway server ARP table or cache.

- TCP/IP configuration information can be displayed using different utilities, depending on the operating system:

  - ipconfig—Windows NT and Windows 2000 and later (command-line)
  - winipcfg—Windows 95, 98, and 2000 (graphical interface)
  - ifconfig—UNIX and Linux (command-line)

- Transmission Control Protocol (TCP) is used to make reliable and connection-oriented transmissions. It ensures delivery of your information. TCP is used with protocols like HTTP and FTP.

- User Datagram Protocol (UDP) is a “best effort” connectionless transmission used to make fast transfers when reliability is not an issue. UDP is used with protocols like DNS and DHCP.