Ethernet Cable

Ethernet is a family of computer networking technologies for local area networks (LANs) which is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory or office building. The defining characteristics of LANs, in contrast to wide areanetworks (WANs), include their usually higher data-transfer rates,smaller geographic area, and lack of a need for leased telecommunicationlines.Standardized in IEEE 802.3 Ethernet has largely replaced competingwired LAN technologies. Systems communicating over Ethernet divide a stream of data into individual packets called frames. Each frame contains source and destination addresses and error-checking data sothat damaged data can be detected and re-transmitted. The standardsdefine several wiring and signaling variants. The original 10BASE5 Ethernet used coaxial cable as a shared medium. Later the coaxial cableswere replaced by twisted pair and fiber optic links in conjunction withhubs or switches. Data rates were periodically increased from theoriginal 10 megabits per second, to 100 gigabits per second. Since itscommercial release, Ethernet has retained a good degree ofcompatibility. Features such as the 48-bit MAC address and Ethernetframe format have influenced other networking protocols.

Advanced networking

Simple switched Ethernet networks, while a great improvement over repeater-based Ethernet, suffer from single points of failure, attacks that trick switches or hosts into sending data to a machine even if it is not intended for it, scalability and security issues with regard to broadcast radiation and multicast traffic, and bandwidth choke pointswhere a lot of traffic is forced down a single link. Advanced networkingfeatures in switches and routers combat these issues through meansincluding spanning-tree protocol to maintain the active links of thenetwork as a tree while allowing physical loops for redundancy, portsecurity and protection features such as MAC lock down and broadcastradiation filtering, virtual LANs to keep different classes of usersseparate while using the same physical infrastructure, multilayerswitching to route between different classes and link aggregation to addbandwidth to overloaded links and to provide some measure ofredundancy.

Varieties of Ethernet

Networking advances IEEE 802.1aq (SPB) include the use of the link-state routing protocol IS-IS to allow larger networks with shortest path routes between devices. The Ethernet physical layer evolved over a considerable time span and encompasses quite a few physical mediainterfaces and several magnitudes of speed. The most common forms usedare 10BASE-T, 100BASE-TX, and 1000 BASE-T. All three utilize twisted paircables and 8P8C modular connectors. They run at 10 Mbit/s, 100 Mbit/s,and 1 Gbit/s, respectively. Fiber optic variants of Ethernet offer highperformance, electrical isolation and distance (tens of kilometers withsome versions). In general, network protocol stack software will work similarly on all varieties.