Ethernet and its dependence
Ethernet is a physical and data link layer technology for Local area Networks (LANs). Ethernet was invented by engineer Robert Metcalfe.
When first widely deployed in the 1980s, Ethernet supported a maximum theoretical data rate of 10 megabits per second (Mbps). Later, so-called “Fast Ethernet” standards increased this maximum data rate to 100 Mbps. Gigabit Ethernet technology further extends peak performance up to 1000 Mbps, and 10 Gigabit Ethernet technology also exists.
Higher level network protocols like IP use Ethernet as their transmission medium. Data travels over Ethernet inside protocol units calledframes.
The run length of individual ethernet cablesis limited to roughly 100 meters, but Ethernet networks can be easily extended to link entire schools or office buildings using network bridge devices.
IP (Internet Protocol) is the primary network protocol used on the Internet, developed in the 1970s. On the Internet and many other networks, IP is often used together with the Transport Control Protocol (TCP) and referred to interchangeably as TCP/IP.
IP supports unique addressing for computers on a network. Most networks use the Internet Protocol version 4 (IPv4) standard that features IP address four bytes (32 bits) in length. The newer Internet Protocol version 6 (IPV6) standard features addresses 16 bytes (128 bits) in length.
Data on an Internet Protocol network is organized intopackets. Each IP packet includes both a header (that specifies source, destination, and other information about the data) and the message data itself.
Transmission Control Protocol (TCP) and Internet Protocol (IP) are two distinct network protocols, technically speaking. TCP and IP are so commonly used together, however, that TCP/IP has become standard terminology to refer to either or both of the protocols.
IP corresponds to the Network layer (Layer 3) in the OSI (Open System Interconnection) Model , whereas TCP corresponds to the Transport layer (Layer 4) in OSI. In other words, the term TCP/IP refers to network communications where the TCP transport is used to deliver data across IP networks.
The average person on the Internet works in a predominately TCP/IP environment. Web browsers, for example, use TCP/IP to communicate with Web servers.
Purpose of Network Protocols
Without protocols, devices would lack the ability to understand the electronic signals they send to each other over network connections. Network protocols serve these basic functions:
- address data to the correct recipient(s)
- physically transmit data from source to destination, with security protection if needed
- receive messages and send responses appropriately
Consider a comparison between network protocols with how a postal service handles physical paper mail. Just as the postal service manages letters from many sources and destinations, so too do network protocols keep data flowing along many paths continuously. Unlike physical mail, however, network protocols also provide some advanced capabilities like delivering a constant flow of messages to one destination (calledstreaming) and automatically making copies of a message and delivering it to multiple destinations at once (called broadcasting).
Common Types of Network Protocols
No one protocol exists that supports all the features every kind of computer network needs. Many different kinds of network protocols have been invented over the years, each attempting to support certain kinds of network communication. Three basic characteristics that distinguish one type of protocol from another are:
- simplex vs. duplex. A simplex connection allows only one device to transmit on a network. Conversely, duplex network connections allow devices to both transmit and receive data across the same physical link.
- connection-oriented or connection-less. A connection-oriented network protocol exchanges (a process called a handshake) address information between two devices that allows them to carry on a conversation (called a session) with each other. Conversely, connection-less protocols deliver individual messages from one point to another without regard for any similar messages sent before or after (and without knowing whether messages are even successfully received).
- layer. Network protocols normally work together in groups (called stacks because diagrams often depict protocols as boxes stacked on top of each other). Some protocols function at lower layers closely tied to how different types of wireless or network cabling physically works. Others work at higher layers linked to how network applications work, and some work at intermediate layers in between.
The Internet Protocol Family
The most common network protocols in public use belong to the Internet Protocol (IP) family. IP is itself the basic protocol that enables home and other local networks across the Internet to communicate with each other.
IP works well for moving individual messages from one network to another but does not support the concept of a conversation (a connection over which a stream of messages can travel in one or both directions). TheTransmission Control Protocol (TCP) protocol extends IP with this higher layer capability, and because point-to-point connections are so essential on the Internet, the two protocols are almost always paired together and known as TCP/IP.
Both TCP and IP operate somewhere in the middle layers of a network protocol stack. Popular applications on the Internet have sometimes implemented their own protocols on top of TCP/IP.HyperText Transfer Protocol (HTTP) is used by Web browsers and servers worldwide. TCP/IP in turn runs on top of lower-level network technologies like Ethernet. Other popular network protocols in the IP family include ARP, ICMP and FTP.
How Network Protocols Work
The Internet and most other data networks work by organizing data into small pieces calledpackets. These packet switching networks require packets to be organized in specific ways according to the protocols the network supports. This approach works well with the technology of modern networks as these all handle data in the form of bits and bytes(digital ‘1’s and ‘0s’).
Each network protocol defines rules for how its data packets must be organized (formatted). Because protocols like Internet Protocol often work together in layers, some data embedded inside a packet formatted for one protocol can be in the format of some other related protocol (a method called encapsulation).
Protocols typically divide each packet into three parts – header, payload and footer. (Some protocols, like IP, do not utilize footers.) Packet headers and footers contain contextual information required to support the network, including addresses of the sending and receiving devices, while payloads contain the actual data to be transmitted. Headers or footers also often include some special data to help improve the reliability and or performance of network connections, such as counters that keep track of the order in which messages were sent, andchecksums that help network applications detect data corruption or tampering.
How Network Devices Use Protocols
The operating systems of network devices include built-in support for some lower level network protocols. All modern desktop computer operating systems support both Ethernet and TCP/IP, for example, while many smartphones support Blootooth and protocols from the WiFi family. These protocols ultimately connect to the physical network interfaces of a device, like its Ethernet port and Wi-Fi or Bluetooth radios.
Network applications in turn support the higher level protocols which talk to the operating system. A Web browser, for example, is capable of translating addresses like ‘http://mynetworks.me/’ into HTTP packets that contain the necessary data that a Web server can receive and in turn send back the correct Web page.
Network connector structure
Network connectors define the broker-to-broker links that are the basis of a broker network. Network structure design is required for any computer network whether it is office or home network. We make network structure design before installing and connecting the hardware and software. We gather requirements and make a plan to avoid from future issues and shape a secure and reliable computer network. Network design is made according to the type and size i.e. home or small business or large enterprise. We install hardware including switches, data cabling, equipment setup like modems, routers and other devices. This is called initial network infrastructure implementation.
The design concept based on network structure, network design, network management, network support and network security.