SIMULATION AND NETWORK PERFORMANCE

The course is aimed at introducing the main techniques of analysis and design for computer networks with the goal of assessing their performance. Specifically, the following aspects will be emphasised:
- understanding of the design principles for computer networks, their protocols and services;
- knowledge of the main formalismo for modelling computer and telecommunication system (with attention to the simulation models)

At the end of the course the student will be able to:
- program a simple simulator for the performance evaluation of a network protocol or a network architecture
- scientifically interpret the outcomes of a simulation experiment
- identify the “performance patterns” in a networking system

The course has the following pre-requisites:
- programming in a procedural or object orientated language
- knowledge of the basics tools of descriptive statistics (average, dispersion index)
- continuous and discrete random variables: moments, maximum likelihood estimators

1. Introduction (1 week)
Modeling. Simulation. Computer systems performance evaluation.
Types of simulations. Examples from different application domains.
Network simulations. Network protocols. Network performance evaluation.

2. Fundamentals (1 week)
Random number generators. Basics of random variate generation.
Discrete and continuous random variables. Common probability distributions.
Monte Carlo simulation. Queueing models. Markov chains.
Classic queues: M/M/1, M/M/1/K, M/M/c/c, M/M/∞, M/G/1.

3. Discrete-Event Simulation (1 week)
Time-stepped simulation. Trace-driven simulation.
Discrete-event simulation (DES). DES concepts and event scheduling.
DES examples. Simulation debugging. Simulation verification and validation.

4. Simulation Input/Output Analysis (1 week)
Stochastic properties of simulations. Transient and steady-state analysis.
Confidence intervals. Batch means analysis. Correlation analysis.
Workload characterization. Goodness of fit tests.

5. Network Simulations (1 week)
Network modeling. Topology models. Protocol models. User models.
Traffic models. Mobility models. Examples: IEEE 802.11, TCP, VANETs.

Notes and slides from the teacher

The exam can be given in two ways:
- one written exam and an oral discussion
- one or two lab assignments (depending on the effort required by the exercise) and an oral discussion of the course topics

The written exam consists of open questions on the topics of the course and exercises. The exercises are aimed at verifying the student's skills on the application of theoretical models in problems. The open questions are aimed at verifying the theoretical knowledge of the student.
The lab projects verify the skills of the student on applying theoretical notions in practical situations.

Frontal Lessons and seminars

English

written and oral