Which of the following measures the performance overhead in an ISL between two switches?

Bandwidth measures the maximum data transfer rate over a connection, not the time delay or overhead in terms of responsiveness.

Latency specifically measures the time delay for a packet or signal to travel from one point to another, which in the context of an Inter-Switch Link (ISL) between two switches, directly quantifies the performance overhead in terms of signal propagation delay and processing time. High latency on an ISL significantly impacts the overall performance and responsiveness of the Fibre Channel fabric.

Multipathing is a technique to improve performance and reliability by using multiple paths to storage, not a direct measure of overhead on a single ISL.

A "Hop" refers to the passage of data between two network devices (like routers or switches), which counts the number of intermediary devices but does not quantify performance overhead.