IJSRST11845253 | Received : 10 March 2018 | Accepted : 24 March 2018 | March-April-2018 [ (4) 7 : 105-110 ] © 2018 IJSRST | Volume 4 | Issue 7 | Print ISSN: 2395-6011 | Online ISSN: 2395-602X Themed Section: Science and Technology 105 Basics of Quality of Services (QoS) Chetan J. Ghyar, Dr. Makarand R. Shahade, Swapnil V. Bamb, Vrushali B. Mankar IT Department, J.D.I.E.T , Yavatmal, Maharashtra, India ABSTRACT Quality of service (QoS) is becoming an increasingly important aspect of today‟s world in the infrastructure of networking. QoS is not only necessary for voice and video streaming over the network, it is also important for supporting the growing Internet of Things (IoT). But it is also a challenging task in the networking. Providing a QoS guarantees becomes more difficult when you add the complexities of wireless and mobile networks. This paper elaborates the concept of QoS, Techniques to improve the QoS such as scheduling, traffic shaping, admission control. In scheduling there are three types FIFO queuing, Priority queuing and weighted queuing. In traffic shaping there are Leaky bucket and Token bucket techniques discusses. Also here we introduce the two deploying QoS model name as Integrated Services (IntServ) and Differentiated Services (DiffServe). Keywords: Bandwidth, Delay, Jitter, Packet Loss, TCP, UDP, DSCP, TC. I. INTRODUCTION QoS stands for the „Quality of Service‟ and it defines “the quality of service as something a flow seeks to attain”. QoS has the ability to provide different priority to different users, applications, data flows, or to guarantee a certain level of performance to a data flow over a network. The goal of the QoS is to provide guarantees on the performance of a network to deliver desired results. A network monitoring system is use in the network to insure that the networks are performing at a desired level or not. QoS is more important for the new generation of internet application, because most of the applications based on internet uses the concept of IoT. In the relation between client and ISP, Figure 1. Characteristics of Network Traffic QoS is more important because client expected to take service guarantees from their ISPs. Traffic over network while sending a data from source to destination in the network affects the quality of QoS. There are four main characteristics of network traffic that we must to deal with 1. Bandwidth: Bandwidth is the rate of amount of data that can be transmitted over a neṭwork in the fixed interval of time. Bandwidth is observe in both analog and digital communication system. It is usually measure in the Bit per second (i.e. bit/sec) or may be in the Byte per second (i.e. byte/sec) in the digital system and for analog system it is measure in the cycle per second (cycle/sec) or in Hertz (i.e. Hz). Bandwidth is also called as the carring capacity of the channel. Bandwidth of both the source and destination must be matches with each other for proper communication. Because while we sending a data from source to destination all the data that we send from source over