The Start Frame Delimiter (SFD) is the 8-bit (1-byte) value marking the end of the preamble of an Ethernet frame. The SFD is immediately followed by the destination MAC address. It has the value 10101011.
The preamble of an Ethernet frame consists of a 56-bit (7-byte) pattern of alternating 1 and 0 bits, which allows devices on the network to easily detect a new incoming frame. The SFD is designed to break this pattern, and signal the start of the actual frame.
Famous quotes containing the words start and/or frame:
“Do we write books so that they shall merely be read? Don’t we also write them for employment in the household? For one that is read from start to finish, thousands are leafed through, other thousands lie motionless, others are jammed against mouseholes, thrown at rats, others are stood on, sat on, drummed on, have gingerbread baked on them or are used to light pipes.”
—G.C. (Georg Christoph)
“The warped, distorted frame we have put around every Negro child from birth is around every white child also. Each is on a different side of the frame but each is pinioned there. And ... what cruelly shapes and cripples the personality of one is as cruelly shaping and crippling the personality of the other.”
—Lillian Smith (1897–1966)