As with the Interframe Gap( IFG), the Bandwidth Allocation Gap prevents a frame from being sent out before the BAG time expires. In addition to the minimum time interval between Ethernet frames, the BAG time also determines the frame length. The BAG interval is specified in milliseconds and can be between 1 ms and 128 ms and is represented in 8 bits. With a maximum Ethernet frame length of 1,518 bytes and a BAG value of 4 ms, this results in a maximum data throughput of approximately 380 kBytes per second.
The BAG method is used in the virtual links in Avionics Full Duplex Switched Ethernet( AFDX) with values between 1 ms and 128 ms, and also in automotive technology in TTEthernet with BAG values from 1 µs.