Bit Time

Bit time is a concept in computer networking. It is defined as the time it takes for one bit to be ejected from a Network Interface Card (NIC) operating at some predefined standard speed, such as 10 Mbit/s. The time is measured between the time the logical link control layer 2 sublayer receives the instruction from the operating system until the bit actually leaves the NIC. The bit time has nothing to do with the time it takes for a bit to travel on the network medium, but has to do with the internals of the NIC.

To calculate the bit time at which a NIC ejects bits, use the following:

bit time = 1 / NIC speed

To calculate the bit time for a 10 Mbit/s NIC, use the formula as follows:

bit time = 1 / (10 * 10^6) = 10^-7 = 100 * 10^-9 = 100 nanoseconds

The bit time for a 10 Mbit/s NIC is 100 nanoseconds. That is, a 10 Mbit/s NIC can eject 1 bit every 100 nanoseconds.

Bit time is distinctively different from slot time, which is the time taken for a pulse to travel through the longest permitted length of network medium.

Famous quotes containing the words bit and/or time:

    “I’m a bit of a P.T. Barnum. I make stars out of everyone.”
    —Donald Trump (b. 1946)

    “Now is the time for drinking [nunc est bibendum], now is the time to make the earth shake with dancing.”
    —Horace [Quintus Horatius Flaccus] (65–8 B.C.)