Velocity of propagation

The Velocity of Propagation (VoP) is the ratio of transmission speed compared to the speed of light. This parameter is used for communication media such as data cables (e.g., Category 5 cable cables). Transmission in a vacuum would have a VoP of 100.

Plenum data cable typically has a VoP of around 72 (72% of the speed of light) and riser cable around 70. This would correspond to 216000km/s and 210000km/s (4.63ns/m and 4.76ns/m) respectively.