We often complain about our connection not being fast enough. In this topic, we will look at the five main reasons why a connection is not as good as we'd like it to be.
The five main factors affecting network performace are:
- Lack of bandwidth
- Too many users
- Transmission media
- Error rate
- Latency
Lack of Bandwidth
Bandwidth is the amount of data which can be transmitted over a given period of time. It is not a measure of speed.
Imagine two roads. The first has one lane, the second has four lanes. Both have the same speed limit. The four lane road can carry more vehicles at the same time, so more can get through — it has a greater bandwidth.
Measured in bits per second, often called the bit rate.
Too Many Users
When too many devices are trying to share the bandwidth, devices will need to wait to transmit their data.
Imagine a busy road. Traffic trying to join the road will have to wait for a gap. The busier the road, the longer they will have to wait.
Transmission Media
Different types of transmission media have different bandwidth capacity.
Wired connections have greater bandwidth than wireless connections, so trying to send lots of data over Wi-Fi will usually take longer than over Ethernet.
Error Rate
Poor quality connections create errors in the transmitted data, so devices will usually try to resend it which increases the time taken to send a valid message.
Wi-Fi is particularily suseptable to errors as it tries to pass through thick walls or encounters electromagnetic interferrence.
If two devices on a connection try to send data at the same time, the data will collide and the transmission will fail. This is called a data collision.
Latency
Latency is a measure of how long it takes a message to travel from one device to another
- High latency: high number of delays
- Low latency: low number of delays
High latency can be caused by many factors, including one or more of the other factors already stated.