Although the word sounds negative, collisions are a normal part of a healthy network. A collision is the mechanism used by the network to control access and to allocate shared bandwidth among devices that want to transmit at the same time on a shared medium. Collision detection allows the two devices to identify that they both want to transmit at the same time. While collisions are normal, a high collision rate can indicate network problems.
Collision rates are usually below 10 percent but even values as high as 50 percent do not have to be problematic. However, higher collision rates typically indicate overload problems for a network. High collision rates may cause delays in transmitting data. An increase in collisions may also indicate that network utilization and network errors are increasing. Through Network Monitoring, you can detect the patterns to detect unusual collision rates and prevent problems before they occur.