The capacity of the link is known as __________ of the link.

Concept

In data communication, the bandwidth of a link is the maximum rate at which data can be carried across that link. "Capacity" and "bandwidth" describe the same property of the channel: the upper limit on how much data the link can transfer per unit time. So the capacity of a link is simply its bandwidth.

Applying it here

The blank asks for the term that names a link's data-carrying capacity. That term is bandwidth, because bandwidth is defined precisely as the maximum amount of data a link can transmit in a given time. A higher-bandwidth link can move more bits per second, i.e. it has a larger capacity.

Capacity vs. bandwidth (the reported doubt)

These two words are often used interchangeably for a link's maximum throughput. The subtle distinction in everyday use:

• Bandwidth / capacity: the theoretical maximum data rate the link can support (e.g. a 100 Mbps line). This is a fixed property of the channel.

• Actual / used data rate: how much of that capacity is currently in use at a moment (the live traffic). This is always less than or equal to the capacity.

When an exam says "the capacity of the link", it is naming the maximum that the link can carry, which is its bandwidth.

Why the other terms do not fit

• A count of the routers a packet crosses measures path length, not how much data a single link can carry.

• The time taken for a bit to travel across the link measures latency, a duration, not a data-carrying rate.

• The amount of traffic actually present on the link is the live usage at a moment, which can be far below the link's maximum.