‫So either Ned has been a relatively inexpensive, reasonably fast and very popular land technology for,
‫gosh, several decades.
‫It was commercially introduced in 1980 and first standardized in 1983 as I Tripoli eight oh two to three.
‫It has since been refined to support higher bit rates and longer linked distances.
‫Ethernet has since become the most popular and probably the most widely deployed network technology
‫in the world.
‫Many of the issues involved with Ethernet are common to many network technologies, and understanding
‫how Ethernet addresses these issues can build a foundation that will improve your understanding of networking
‫in general.
‫So let's keep the design principles of Ethernet simple.
‫The basic idea of its design is it multiple computers have access to it and can send data at any time.
‫If two computers send data at the same time, a collision will occur.
‫So and when this happens, the data centers is not going to be usable.
‫In general, both computers will stop sending and wait a random amount of time before they'll try again.
‫Now, a special protocol was developed to deal with such problems.
‫It's called carrier sends multiple access with collision detection or might be easy to say CSM a CD.
‫Today, Ethernet cables look like, well, thick telephone cables, modern cables connect to hubs or
‫switches, and each cable runs from a computer's network interface card, the Nicey to such a box.
‫Now here are the most widely known Ethernet cables.
‫10 based two and 10 base five cables are what I would call retro coaxial cables.
‫You don't see them much today.
‫Each computer has a T plugged into it and cables plug into each side of that T.
‫Ten based, T100 based T-1000 based are all unshielded, twisted pair or UTP cables, which look a lot
‫like thick phone cables, and they go from each computer to a hub or a switch.
‫Initial numbers indicate the supported speed, so the 10 will stand for 10 megabits per second and a
‫thousands dans four 4000 megabit, also known as gigabit or one gigabit.
‫Ben, bass cables are the same as tin based tea, but they are fibre cables, and they'll transmit light
‫pulses instead of electrical signals over copper.
‫A data packet on an Ethernet link is called an Ethernet packet, which transports an Ethernet frame
‫as its payload.
‫An Ethernet frame is preceded by a preamble and start frame delimiter, or SFD, which are both part
‫of the Ethernet packet at the physical layer, right?
‫There are four types of Ethernet frames.
‫And the most common one is the Ethernet to frame, also known as DeCSS frame.
‫We're talking about the Ethernet to frame at the moment.
‫Each Ethernet frame starts with.
‫An Ethernet header which contains destination and source Mac addresses as its first two fields.
‫The middle section of the frame is payload data, including any headers for other protocols.
‫For example, internet protocol carried in the frame.
‫The frame ends with a frame check sequence, or FCX, which is a 32 bit Sekulic redundancy check used
‫to detect any in transit corruption of data.