Zenith Zenith The zenith is an imaginary point directly "above" a particular location, on the imaginary celestial sphere. "Above" means in the vertical direction opposite to the apparent gravitational force at that location. The opposite direction, i.e. the direction in which gravity pulls, is toward the nadir. The zenith is the "highest" point on the celestial sphere. The word "zenith" derives from an inaccurate reading of the Arabic expression (), meaning "direction of the head" or "path above the head", by Medieval Latin scribes in the Middle Ages (during the 14th century), possibly through Old Spanish. It was reduced to 'samt'
Point-to-Point Protocol over Ethernet the AAL5 payload packet. The total ATM payload overhead is 2 + 6 + 18 + 10 + 8 = 44 bytes in the LLC case if the Ethernet MAC FCS is present, or 2 + 6 + 14 + 10 + 8 = 40 bytes with no FCS. In the more efficient VC-MUX case the ATM payload overhead is 2 + 6 + 18 + 2 + 8 = 36 bytes (with FCS), or 2 + 6 + 14 + 2 + 8 = 32 bytes (no FCS). However the true overhead in terms of the total amount of