 Hello and welcome to the course introduction to the course on introduction to computer and network performance analysis using queuing systems. My name is Professor Varshaapte and I am a faculty member in the department of computer science and engineering at IIT Bombay. So today I will just be giving a course introduction, just giving the content of the course and who should be doing it, so let us get started. So the computer system and network performance basically relates to performance quality of systems and networks. Things like download delays or amount of work done per unit time, for example, stock exchange may be interested in how many trades it is doing per second at the peak hour. So we all know that good performance is actually very critical to computer systems and networks and it is not only features that are important. But in any case we run into slow systems. So it is a problem and we do need to look at it and that is what this course is about. So let us ask some questions of who, what, why, how, I am sure you have a lot of questions about the course, so I will go over all those details. So what exactly is the course about, we will in this course we focus on analyzing performance of systems. The main question we ask is given some essential description of a system, computer or network system, can we estimate some performance metric? For example, can we estimate the download delay of a file storage application, if we are given some description about it or can we actually estimate the number of trades per hour done by a stock exchange server, why are these questions important? For businesses they are important because if I am the stock exchange business owner then I want to do as many trades per day as possible. If I am the stock exchange owner I also want to make keep my users happy, they should be able to do that trade very fast, if they click on a button they should get the trade done in a few seconds or milliseconds, right. And if that is not happening then how does one improve performance and there are many ways to be able to size your resources, to be able to answer some configuration questions like how many cores should the server have? What is a bottleneck in my system? So these are the questions that are very important, there are some design questions also like scheduling policies and so on, I should be able to answer those. So analyzing being able to answer the question as to if my bandwidth of my link is to the data center is this, then will my users be satisfied? This is a very important question to answer. How do we answer it? We use the theory of queuing systems or in short we call it queuing theory. What is queuing theory? It views everything as queuing systems, it is a universal mathematical theory that models these resources as queuing systems, basically things of everything as something that users have to stand in a queue for, the users can be packets or something. So everything you know a web server, core and any part of the all the network elements everything is queues and what it comes with is it gives us a set of laws that relate performance metrics to system parameters and it gives us some formulae by which these estimates can be done. So how is this course different from other queuing system courses? This is this part is important for those of you who are listening who know what queuing systems is about have been wanting to do a course and there are actually multiple courses on NPTEL itself and in the world in general on queuing systems. So what is how is this course different? My emphasis in this course is going to be on intuitive understanding and all derivations and everything that we do are intuitive, the probability background is very minimal. The actual queuing systems if you want to do it in deep you actually need some heavy mathematical background we are not going to need that in this course at all. For example, there is this thing called stochastic processes that is not going to be there at all in this course we will focus on some like low load behavior, high load behavior and by doing that we will reduce the mathematical requirement of the course and we will also continue to do comparison with measurement. syllabus is actually given on the website this is I am not going to go over this in detail you can look at it on the course webpage this is the syllabus this is just for a quick reference if you want to see one slide on this later. Again what is not the syllabus we will not do advanced maths and in this we will not be covering details of protocols everything we do in queuing systems is in an abstract way. Who should take this course? Anybody who is interested in operating systems networked applications virtualized systems cloud computing networks wired wireless queuing systems is actually the foundational theory to understand all of these systems your quality of work in these systems will improve a lot if you do this course and professionals if you are actually not just doing code development but architecting networked applications you should do this course and if you are doing performance testing or load testing this is extremely important for the performance testing and load testing teams. The prerequisites is undergraduate background in operating systems computer architecture and computer networks at a very high level again details are not required and mathematics only 12 standard level. So that was the introduction I hope you will be interested in taking this course and looking forward to you registering for this course thank you.