Ethernet Frame Format

Ethernet frame is a certain packet data on Ethernet link. Ethernet is a whole family for LAN (local area networks) technology of computer networking which are frame-based. In the market in has been available from the year 1980 and has replaced other competing LAN standards. Ethernet was evolved with an aim to cover higher bandwidth and enhanced control methods of media access. It includes unique physical media that attracted the networking sections and soon its demand in the market raised its heights. The long co-axial cables that were used to connect computers were replaced by point connecting links, Ethernet repeaters; these reduced the installation costs, improved the way systems were managed and allowed scope for troubleshooting too. These features were new at that moment and made things very convenient for the networking section. This network topology connected the system in a manner that when a single system transmitted data then it was heard by all other stations. So a transmitting signal was passed on and obeyed by all other connected systems.

With help of Ethernet, a bulky set up was replaced with quite a convenient and neat easy set up. There are broadcast domains in Ethernet networks, but not a single clock signal is present here. Systems of Ethernet should be able to determine whether the wire is been used or not and it has to send data enough for handling its remote stations and allowing them to synchronize well and properly. The systems have to follow an Ethernet Frame Format. The structure has sections, to start with is Preamble, a bit stream that enables synchronizing of the communication between the transmitter and the receiver and is an alternative pattern of 56 binary zeroes and ones. After preamble which has 7 bytes is Start frame delimiter that is 10101011 always and its specific use is indication of the beginning for frame information, it contains 1 byte. This is followed by destination and source MA. Destination MAC is the receiving data machine's MAC address; this has 2 or 6 bytes.

The source MAC is the transmitting data machine's MAC address having the same byte options as former one. The following is the Length; this is Ethernet frame's entire length that is not often larger than maximum 1500 though can hold as much as 65,534. The second last in the Ethernet Frame Format is padding/data where all data has to be inserted. This section has 4 sub sections or field; DSAP, SSAP, CTRL, NLI. The last in the structure is this is FCS that is frame check sequence that allows detecting of the error by Ethernet or reject frame if any damage appears.