653. What is interframe gap?

An interframe gap, often abbreviated as IFG, serves as a brief period of idle time inserted between frames on a network to enable the receiving station to process the previous frame and prepare for the next one. This gap is essential in Ethernet networking for several reasons. Primarily, it helps in avoiding frame collisions and ensures that data integrity is maintained across a shared medium. In Ethernet, this gap is typically measured in time units rather than distance, characterized by a specific number of idle bits or nanoseconds.

For Ethernet networks, the standard interframe gap is 96 bit times, which is the time it takes to transmit 96 bits on the network, and this equates to 9.6 microseconds at 10 Mbps Ethernet speed. The concept of the interframe gap varies slightly in relevance and application with different network technologies and speeds (e.g., Gigabit Ethernet, 10 Gigabit Ethernet), but its fundamental purpose of providing a buffer period between frames remains consistent.

This concept is critical in network design and operation, impacting network performance, collision avoidance, and the overall efficiency of data transmission in shared or half-duplex environments. In full-duplex settings where two devices can simultaneously send and receive data without collisions, the importance of the interframe gap as a collision avoidance mechanism decreases but it may still be relevant for ensuring proper frame separation and timing.