Network congestion (also congestion):
|“||in the IP network environment occurs when the amount of traffic carried by a link or node exceeds its capacity and results in a deteriorated quality of service level, such as packet delay or loss.||”|
"With non-delay sensitive applications, such as e-mail or instant messaging, the effects of packet delay or loss on the IP network are likely unnoticed by the end user. For delay-sensitive applications, such as VoIP, real-time gaming, or IP television, packet delay or loss can affect the application's ability to operate or its service quality. Service providers, however, have the ability to design and manage their networks to avoid or minimize network congestion and to prevent and respond to network events."