IP QoS (Quality of Service) refers to the performance of IP packet flow through networks.The main aim being to deliver end-to-end QoS to user traffic.Quality of Service is a set of small metrics, including service availability, delay, delay- variation, throughput, and packet loss rate.

The user has the Internet which has become a powerful consumer and business tool. With IP QoS, service providers can achieve greater profitability through more business and more efficient use of:

• bandwidth
• enhanced service differentiation
• better-than-best-effort service and
• customized solutions.

• Integrated Services Architecture (Int-Serv) and
• Differentiated Services Architecture (Diff-Serv).

In addition to the architectural framework, other elements are required to build real world IP networks that meet QoS requirements.Like in the sense that the network must quickly recover from nodal or link failures.The QoS mechanisms at each node must be configured to work in such a way so that end-to-end QoS across the network is delivered.This is a sizably difficult work and takes into account many things to make it happen. The rapid development in the field of IP QoS has given way for a number of reliable components:

• classification of queues which separate traffic accordingly.
• configuration of switches and routers to meet SLAs.
• traffic marking, and policing mechanisms for entry traffic.
• for the exit traffic there is filtering to ensure congestion control.
• active output queue management.
• packet discard algorithms.
• outgoing interface traffic monitoring.
• ensuring safety of premium traffic.