Das Video kommt von YouTube: erst beim Abspielen verbindet sich die Seite mit YouTube (Google).
What is Ethernet?
Das Wichtigste aus dem Video
Tipp auf eine Zeit – das Video springt genau dorthin.
Transkriptautomatisch erstellt · 61 Zeilen
- Have you heard of IEEE 802.3? It has a long history and has to do with our topic today, Ethernet.
- before we get started on today's video if you love our videos,
- be sure to click the like button below. then, make sure to click subscribe
- and the little bell to receive notifications of new RealPars videos. This way you never miss another one!
- Ethernet is a communication standard that was developed in the early ’80s to network computers and other devices
- in a local environment such as a home or a building. This local environment is defined as a LAN (Local Area Network)
- and it connects multiple devices so that they can create, store and share information with others in the location.
- Ethernet is a wired system that started with using coaxial cable
- and has successfully progressed to now using twisted pair copper wiring and fiber optic wiring.
- Let’s break for a trivia question. Who invented twisted pair wiring?
- Alexander Graham Bell invented twisted pair wiring in 1881. In 1983, Ethernet was standardized
- into the standard IEEE 802.3 by the Institute of Electrical and Electronic Engineers (IEEE).
- This standard defined the physical layer and the MAC (media access control) portion of the data link layer of wired Ethernet.
- These two layers are defined as the first two layers in the OSI (Open Systems Interconnection) model
- The “physical” layer consists of the following components: Cabling and Devices.
- First, let’s take a look at Ethernet Cabling; As stated previously, Ethernet cables come as coaxial cable,
- which is not very common except in older installations, twisted pair, and fiber optic.
- The most common cable is twisted pair cables, with the latest being Category 6 with speeds up to 1 Gbps
- and Cat6a and Cat 7 with speeds up to 10 Gbps. Category 5 and 5e cables are both still used in many existing applications
- but handle the lower speeds between 10 Mbps to 100 Mbps but are more susceptible to noise.
- The Ethernet twisted pair utilizes RJ-45 eight-pin connectors at either end of the cable that is pinned for transmitting
- and receiving data in either half or full-duplex mode. Half-duplex transmits data in one direction at a time
- while “full-duplex” allows data to be transmitted in both directions at the same time.
- Full-duplex in Ethernet can be achieved by using two pairs of wires to allow data to travel both directions simultaneously.
- Fiber optic cable uses glass or plastic optical fiber as a conduit for light pulses to transmit data.
- It has allowed Ethernet to travel farther distances at higher speeds. Fiber optic cables use several different types of connectors
- that vary depending on your application needs. Some of the different types are SFP
- (Small Form Pluggable or Small Factor Pluggable) and SC (Subscriber Connector, also known as Square Connector or Standard Connector).
- In order to use fiber optic in an Ethernet network that utilizes twisted pair Ethernet cabling,
- you need to use an Ethernet to fiber converter that will allow your network to take advantage of the higher speeds of fiber optic
- and lengthen the distance that the Ethernet network can reach. How about the Ethernet devices?
- Ethernet devices are consist of computers, printers or any device which either have an internal NIC
- (Network Interface Card) or an external one that is USB or PCI based.
- “Switches” and “Routers” that act as the director of the network and connect multiple computers
- or even networks together to enable communication between all the different devices.
- “Gateways” or “Bridges” are used to connect multiple Ethernet networks together and allow communication across them.
- Gateways connect two dissimilar networks together while a bridge connects two similar networks together
- so that you only see one network. Now that we have discussed the basic physical components of Ethernet,
- let’s move into the second layer of the OSI model, the “data link” layer. The data link layer can be split into two sections;
- the Logical Link Control (LLC) and the Media Access Control (MAC).
- The Logical Link Control establishes paths for data on the Ethernet to transmit between devices.
- The Media Access Control uses hardware addresses that are assigned to Network Interface Cards (NIC)
- to identify a specific computer or device to show the source and destination of data transmissions.
- Ethernet transmits data packets in this data link layer by using an algorithm called CSMA/CD
- (Carrier Sense Multiple Access with Collision Detection). CSMA/CD is used as a standard for Ethernet
- to reduce data collisions and increase successful data transmission. The algorithm first checks to see if there is traffic on the network.
- If it does not find any, it will send out the first bit of information to see if a collision will occur.
- If this first bit is successful, then it will send out the other bits while still testing for collisions.
- If a collision occurs, the algorithm calculates a waiting time and then starts the process all over again
- until the full transmission is complete. When you use the faster Ethernets in full-duplex modes
- and incorporate switches, then you are utilizing a star topology
- between the switch ports and the devices. This allows for more direct transmission paths and fewer collisions
- as compared to a bus topology where all devices share the same paths. Ethernet capabilities are quickly changing with new technologies emerging every day.
- And while we are currently on the brink of successfully moving into speeds higher than the current 1 Gbps with 10 Gbps emerging over the last few years,
- these new Ethernet technologies will be costly. Also, your possibilities for the information world
- can seem endless when you connect this Ethernet local area network to the internet to create a very large WAN (Wide Area Network).
- But that is a story for another day. All in all, Ethernet is popular
- because it strikes a good balance between speed, cost, and ease of installation.
- These benefits, combined with wide acceptance in the computer marketplace and the ability to support virtually all popular network protocols.
- Want to learn PLC programming in an easy to understand format and take your career to the next level?
- Head on over to realpars.com
Zum Nachlesen
EthernetDerzeit sind Übertragungsraten von 1, 10, 100 Megabit/s (Fast-Ethernet), 1000 Megabit/s (Gigabit-Ethernet), 2,5, 5, 10, 25, 40, 50, 100, 200 und 400 Gigabit/s …
Local Area NetworkFast-Ethernet 100BASE-TX und Gigabit-Ethernet 1000BASE-T sind innerhalb der Ethernet-Familie die am weitesten verbreiteten Varianten. Hauptsächlich für …
Switch (Netzwerktechnik)Switch (vom Englischen für „Schalter“, „Umschalter“ oder „Weiche“, auch Netzwerkweiche oder Verteiler genannt) bezeichnet ein Kopplungselement in …
RechnernetzEin Rechnernetz, Computernetz oder Computernetzwerk ist ein Zusammenschluss verschiedener technischer, primär selbstständiger elektronischer Systeme …