Bottleneck Link

networking

Definition

Bottleneck Link

Let be a path of links from source to destination in a computer network, where each has capacity bits/s.

The bottleneck link of is the link with the smallest capacity:

Its capacity is the bottleneck bandwidth of . No flow along can exceed , regardless of the capacities of other links on the path:

Role in End-to-End Throughput

The bottleneck link upper-bounds the throughput achievable on . All other links may have spare capacity, but the bottleneck determines the ceiling.

Multiple flows

If flows share the bottleneck link, each flow receives at most under fair sharing, assuming no other bottleneck constrains any flow.