What is Quality of Service (QoS)?

Quality of Service is a way of providing a better service to different 'classes' or types of traffic on a Network. You could think of QoS as a bus route in London, as only one type of traffic is allowed in the lane thereby improving its reliability and speed of service. On an IP Network you will have many devices and services all trying to send information along the same routes at the same time and you need some way of prioritising your telephone calls ahead of other non-critical traffic.

Quality of Service usually looks at a number of factors :

			Bandwidth	The rate at which traffic is carried by the network.
			Latency	The delay in data transmission from source to destination.
			Jitter	The variation in latency.
			Reliability	The percentage of packets discarded by a router.

QoS not only involves a robustly working VoIP system, it also includes the network in which that system is running. In addition, there are many other factors and situations affecting the quality of service. If the bandwidth is not sufficient, the network is not properly set up or other such factors outside the VoIP system do not function properly, it is very difficult to achieve good quality of voice.

The IPECS Platform actively guards against a poor Quality of Service by implementing a number of technologies to assist in building a reliable, voice quality Network. These technologies include:

VLAN Tagging (802.1p/Q)
DSCP (DiffServe Code Point)
IP ToS (Type of Service Scheduling)
UDP Port Service Scheduling