In an Ethernet network in which a node receives and processes the frames and forwards the frames to the next node, a time delay per node depends on a maximum variation of the transmit clocks of the nodes.  A node n receives a frame using the transmit clock of the preceding node n−1, and transmits the same frame using its own transmit clock n. A maximum Ethernet frame is 1536 bytes long, i.e. for a precise transmit clock of 100 Mbits, the transmission of this frame would take: 1536 times 8 times 10 ns=122.88 μs.  For a transmit-clock variation of 100 ppm=0.01%, the frame would be longer or shorter by 122.88 μs times 0.0001=12.29 ns.  Thus there would be a maximum variation of 24.58 ns.  This would equate to the transmission of approximately 2.5 bits at 100 Mbits.  A variation depends only on the frame length in bytes, not on a transmission rate.  For Gbits, the frame is only 1/10 as long.  The general rule for the variation is [frame length in bits] times [maximum variation in ppm].  Were jumbo frames to be used (Ethernet frames longer than 1536 bytes), these values would be even higher.  In the nodes there would need to be for each direction an internal FIFO (FIFO stands for “First In First Out”) of at least this size, through which the frame must pass in order that a bit to be transmitted has actually already been received by a node.  This extends a transmission time of the frame through the entire network by the maximum variation in the transmit clocks and the number of nodes.