Final answer:
A transmission of silence is typically found after the trailer of a network frame, indicating no signals are being transmitted on the network medium, marking the end of the frame's transmission.
Step-by-step explanation:
In computer networking, a transmission of silence would typically be found in the trailer of a network frame. Network frames are structures used for encapsulating data that is transmitted over a network and usually consist of a header, payload (where the actual data is carried), and a trailer. The trailer often contains error checking and other control information. Specifically, the trailer may include a Frame Check Sequence (FCS), which is used to detect any errors that might have been introduced during transmission. The silence itself is not explicitly transmitted as data; hence, it does not exist in the payload or header. Instead, it is a period where no signals are transmitted on the network medium, and it occurs after the transmission of a frame's trailer, signalling the end of that frame's transmission.