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:
“It was almost two years ago, while awaiting the imminent birth of my second child, that I decided to start working part-time. This would have been unthinkable to me when I was younger. At twenty-five I should have worn a big red A on my chest; it would have stood for ambition, an ambition so brazen and burning that it would have reduced Hester Prynne’s transgression to pale pink.”
—Anna Quindlen (20th century)
“Predictions of the future are never anything but projections of present automatic processes and procedures, that is, of occurrences that are likely to come to pass if men do not act and if nothing unexpected happens; every action, for better or worse, and every accident necessarily destroys the whole pattern in whose frame the prediction moves and where it finds its evidence.”
—Hannah Arendt (1906–1975)