QoS, as defined
in International Consultative Committee for Telephone and Telegraph
(CCITT) Recommendation E.800, may be considered generically as: "The
collective effect of service performance which determines the degree
of satisfaction of a user of the service."
convergence of voice and data networks into one integrated
infrastructure and for this infrastructure to enable advanced
multimedia services depends on providing quality of service (QoS).
As mentioned earlier, it is a set of mechanisms designed to improve
predictability of network service, and is the measure of a network’s
ability to match service with user and application requirements.
context of a definable administrative authority (such as the network
defined by a service provider’s demarcation points), QoS can be
characterized by a small set of measurable parameters:
Is the reliability of the user’s
connection to the Internet service;
Also known as latency, refers to the
interval between transmitting and receiving packets between two
Also called jitter refers to the
variation in time duration between all packets in a stream taking
the same route;
Is the rates at which packets are
transmitted in a network; this can be expressed as an average or
Is the maximum rate at which packets
can be discarded during transfer through a network; packet loss
typically results from congestion.