Packet Transmission Time

This formula gives the time required to place all bits of a packet onto a communication link. It works because link rate R tells you how many bits can be sent each second, so dividing the total number of bits L by bits-per-second gives the number of seconds needed. It measures only the transmission or serialization delay, not the time for the signal to travel across the network.

Use this when you need to estimate how long it takes a router, switch, modem, or network interface to transmit a packet onto a link. It is useful in networking delay calculations, bandwidth planning, and comparing packet sizes or link speeds.

• Using the packet's travel distance instead of its size in bits
• Forgetting to convert Mbps or kbps into bits per second before dividing
• Confusing transmission time with propagation delay, which depends on distance