The measurable end-to-end performance properties of a network service, which can be guaranteed in advance by a Service Level Agreement between a user and a service provider, so as to satisfy specific customer application requirements.
Note: These properties may include throughput (bandwidth), transit delay (latency), error rates, priority, security, packet loss, packet jitter, etc.
CNSSI 4009-2015 under quality of service
A categorization of different types of network traffic to prioritize latency-sensitive data over non-latency-sensitive data.
NIST SP 800-127