Network Performance

Network performance describes how quickly and reliably a network transfers data. Good performance means files transfer promptly, shared resources open without a pause and connections stay stable. Performance can change as conditions change.

Signs of poor performance

Poor performance appears as slow data transfer, slow loading, buffering, lag or dropped connections. Reliability matters as much as speed, so a quick connection that keeps failing is still performing badly.

What affects performance

Several factors work together, and the weakest one limits the rest:

• Bandwidth — the amount of data the link can carry each second. A wider link moves more data in the same time.
• Number of devices — devices sending and receiving at the same time share the bandwidth. More active devices do not reduce the total bandwidth, but each device gets a smaller share.
• Transmission media — copper, fibre optic and wireless links carry data differently, affecting speed and how easily the signal is disrupted.
• Signal strength, distance and obstacles — a wireless signal weakens with distance from the access point and through walls, floors and solid objects.
• Interference — other radio or electrical signals can corrupt data, so it must be resent.
• Latency — the delay before data arrives. Bandwidth is not latency: bandwidth is how much data can be sent each second; latency is how long data takes to arrive.
• Errors and retransmission — lost or damaged data is resent, wasting time and bandwidth.
• Hardware and servers — an old router, switch or network interface card, or a slow server, caps the speed everything else can reach.

For example, at a climbing centre the check-in tablet slows down on busy afternoons. Two staff phones upload route photos, a backup drive copies CCTV footage over the same connection, and the tablet has an old network adapter. Upgrading the adapter helps, but the tablet still waits while the other transfers use most of the link; the weakest part sets the limit.