EEE 448 Computer Networks with (Network Programming) Course Descriptions. Topics to be covered. Course Objectives. Weekly Schedule.

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EEE 448 Computer Networks with (Network Programming) Lecture #1 Dept of Electrical and Electronics Engineering Çukurova University Course Descriptions The aim of this course is to teach basic

1 EEE 448 Computer Networks with (Network Programming) Lecture #1 Dept of Electrical and Electronics Engineering Çukurova University Course Descriptions The aim of this course is to teach basic concepts in networking, the OSI model, error detection codes, flow control, routing, medium access control, and high-speed networks and to give basic level theoretical infrastructure students about layered network architecture by using C#. Because, the course will be practiced in C# 2 Course Objectives Develop a fundamental understanding of the network design principles and performance metrics Become familiar with the mechanisms and protocols for reliable data communication via a computer network Be able to evaluate the performance of various network technologies and protocols Think as an engineer: What technologies should be employed to build a network with particular specifications? Develop interest in performing research in the area of 3 Computer Networks Topics to be covered Network architectures, performance metrics, layering Medium access control Internetworking, routing End-to-end protocols, flow control Congestion control and resource allocation Applications Network security 4 Introduction Layering, Hardware Network Programming Weekly Schedule Application Layer Session, Transport, Network, DataLink and Physical Layers MultiMedia Networking Network Management Security 5 Course Logistics Textbook Computer Networks: A Systems Approach, L. Peterson, and B. Davie, 5 th edition. Computer Networks: A top-down Approach, Kurose and oss, 6th Edition, Addison-Wesley. Additional eferences Data Networks D. Bertsekas, and. Gallager, 2nd edition Computer Networks, S. Tanenbaum and D. Wetherall, 5th edition, Course Website : eembdersler.wordpress.com Lectures, Homework, Useful links, Supplementary material, Announcements 6 1

Where to find me When the class My Office: EEE bldg: oom 305 Office Hours by appointment My Email: turgayibrikci@hotmail.com Monday?????????? EEE bld Computer Lab: oom 223 9:30 12:00 AM Thursday?

understandable Submit clean, organized, concise and on time your project (back of a flyer is not ok!

2 Where to find me When the class My Office: EEE bldg: oom 305 Office Hours by appointment My Monday?????????? EEE bld Computer Lab: oom 223 9:30 12:00 AM Thursday????? EEE Bld Computer Lab: oom :00 16:00 PM 7 8 Class Expectations Class participation Your input is needed for good discussion Keep up with reading material Present your presentation clean and understandable Submit clean, organized, concise and on time your project (back of a flyer is not ok!) Identify potential project partner early (in one week, if possible) Brush up prior knowledge (Probability theory, C# Programming) Follow academic integrity code (emember EEE117) 9 Assignment Grading Scheme Points Midterm 15% 40% of Project 25% 25% 40% of 60% of Final Exam 35% 60% of Classes Activitives 10% +60% Total 110% 100 Presentation: At least a 15 mins-presentation for the projects (How to use the time, to present the details, to answer the questions will be graded) Midterm and Final Exam: will be setup by the department- Closed books and materials 12 DATA COMMUNICATIONS The term telecommunication means communication at a distance. The word data refers to information presented in whatever form is agreed upon by the parties creating and using the data. Data communications are the exchange of data between two devices via some form of transmission medium such as a wire cable. Characteristics that define effectiveness of data communications Delivery Accuracy Timeliness Jitter A data communications system must transmit data to the correct destination in an accurate and timely manner

Five components of data communication Components of Data Communication System 15 Message is the information (data) to be communicated (text, numbers, images, audio, and video).

3 Five components of data communication Components of Data Communication System 15 Message is the information (data) to be communicated (text, numbers, images, audio, and video). Sender is the device that sends the data message (computer, mobile phone, video camera and so on). eceiver is the device that receives the message. Transmission medium is the physical path by which a message travels from sender to receiver (twistedpare, coaxial, fiber-optic cables and radio waves). Protocol is an agreement between the communicating devices on how communication is to proceed. 16 Data flow modes Data flow modes Simplex as one-way street. Only one of the two devices on a link can transmit; the other can only transmit. Half-duplex, each station can both transmit, but not at the same time. Full-duplex (or duplex), both stations can transmit and receive simultaneously Networks Computer Network is a collection of devices (nodes) interconnected by a single technology (transmission medium link). Networks Node can be a computer, printer, or any other device capable of sending and/or receiving data generated by other nodes on the network. Interconnected computers are two or more computers that able to exchange information. 19 Computer network example 20 3

4 Networks Internet is the network of networks (connection of two or more networks) Intranet is a private business network. Most networks use distributed processing, in which a task is divided among multiple computers. Internet An inter-net: a network of networks. Networks are connected using routers that support communication in a hierarchical fashion Often need other special devices at the boundaries for security, accounting,.. Internet Distributed System is a software system built on top of a network. World Wide Web is a distributed system that runs on top of the Internet. 21 The Internet: the interconnected set of networks of the Internet Service Providers (ISPs) About 17,000 different networks make up the Internet 22 Challenges of the Internet Challenges of the Internet Heterogeneity Address formats Performance bandwidth/latency Packet size Loss rate/pattern/handling outing Diverse network technologies satellite links, cellular links, carrier pigeons Scale 21,220,000,000s of hosts( that is why IPv6) 72,400,000 (2010) 18,000+ administrative domains, Thousands of applications Adversarial environment Oh, and let s make it easy to use 23 How to translate between various network technologies? 24 Naming outing outers send packet towards destination H What s the IP address for It is H H Computer 1 Local DNS Server Translates human readable names to logical endpoints H H H: Hosts : outers

Networks criteria Performance can be measured in many ways, including: 1)Transit time (time required for a message to travel from one device to another); 2) esponse time (elapsed time between inquiry

eliability is measured by : 1) accuracy of delivery; 2)frequency of failure; 3) time it takes a link recover from failure.

5 Networks criteria Performance can be measured in many ways, including: 1)Transit time (time required for a message to travel from one device to another); 2) esponse time (elapsed time between inquiry and response). Performance is often evaluated by two networking metrics: Throughput and delay : To enhance performance we need more throughput and less delay. eliability is measured by : 1) accuracy of delivery; 2)frequency of failure; 3) time it takes a link recover from failure. Security include: 1) protecting data from unauthorized access; 2) protecting data from damage; 3) development recovery policies and procedures. 27 Business Applications Benefits of Computer Networks I - esource Sharing (printers, scanners, storage devices, and sharing information, (client-server model)) - Communication Medium ( ) - Being able to place orders in real time (Purchase) - E-Commerce, M-Commerce 28 Business Applications of Networks Benefits of Computer Networks II Home Network Applications - Access to remote information (e.g. Google) - Person to person communication (chat) - Using social networks (e.g. Facebook) - Interactive entertainment - E- commerce, M-Commerce (web shopping) A network with two clients and one server Network attributes: 1 - Types of connection Network attributes: 2 Topology Point-to-point Multipoint (or multidrop, e.g. broadcasting networks) The topology of the network is the geometric representation of the relationship of all the links and nodes to each other

(10Mbps, 100Mbps, 10Gbps) The most common classification of networks is based on its physical size (scale).

6 Categories of networks Local Area Network (LAN) LAN is a network within a single building or campus of up to a few kilometres in size. LANs share the following characteristics: - their transmission media - their size (restricted small size) - their topology (Bus, ing, Star) - their setting up cost is low - Data transfer rate is high (10Mbps, 100Mbps, 10Gbps) The most common classification of networks is based on its physical size (scale) LAN example LAN topologies: Mesh (1) 35 A fully connected mesh topology (five devices) We need n(n-1)/2 duplex-mode point-to-point links to connect n devices 36 LAN topologies: Mesh (2) LAN topologies: Star (1) Advantages of mesh topology: Eliminating traffic problem (each link is dedicated to pair of devices); obustness (break in one line does not lead to break of all network); Privacy and security; Fault identification and isolation is easy. Disadvantages of mesh topology: Large amount of cabling and I/O ports are required; Wiring can be greater than available space; It is expensive. Mesh mainly is used to connect servers of a hybrid topology network that can include several other topologies. 37 Star topology uses point-to-point connections (station-hub). 38 6

7 LAN topologies: Star (2) In a Star topology, each station is directly connected to a central controller hub. The hub acts as exchange: device sends data to hub, which then relays the data to other device. LAN topologies: Star (3) An isolated LAN connecting 12 computers to a hub in a closet Advantages of star topology: Less expensive than mesh; Less cabling; Easy maintenance. Disadvantages of star topology: One single point of failure hub LAN topologies: Bus (1) Bus topology is multipoint. One large cable acts as a backbone to link all devices in a network. LAN topologies: Bus (2) In a bus topology, all stations are attached to a liner transmission medium (bus) through appropriate hardware interface (tap). Advantages of bus topology: easy to install; efficient use of wiring; Disadvantages of bus topology: One single point of failure backbone cable. Difficult maintenance. IEEE (Ethernet) is an example of bus topology LAN topologies: ing (1) LAN topologies: ing (2) In a ing topology, each station on the network is connected to two other stations, forming a loop or ring. It uses token (signal circulating in a ring) to control transmission. Advantages of ring topology: To add or delete a device requires changing only two connections. Fault isolation is simplified No conflict in the transmission of data. Disadvantages of ring topology: - if one connection fails, the rest of the network will fail. To avoid this a dual ring could be used. IEEE ( IBM Token ing) & FDDI (Fiber Distributed Data Interface) are examples

LAN topologies: Hybrid Network topology Advantages and Disadvantages of Network Topologies Topology Advantages Disadvantages A hybrid topology: a star backbone with three bus

More expensive than bus. ing Efficient. Easy to install. econfiguration difficult. Very expensive. Mesh Simplest. Most fault tolerant. econfiguration extremely difficult.

A MAN spans the distance of a typical metropolitan city. The cost of installation and operation is higher.

Examples of a MAN: 1) part of the telephone company network that can provide a high-speed DSL line to the customer; 47 2) cable TV network.

8 LAN topologies: Hybrid Network topology Advantages and Disadvantages of Network Topologies Topology Advantages Disadvantages A hybrid topology: a star backbone with three bus networks 45 Bus Cheap. Easy to install. Difficult to reconfigure. Break in bus disables entire network. Star Cheap. Easy to install. Easy to reconfigure. Fault tolerant. More expensive than bus. ing Efficient. Easy to install. econfiguration difficult. Very expensive. Mesh Simplest. Most fault tolerant. econfiguration extremely difficult. Extremely expensive. Very complex. Metropolitan Area Network (MAN) (1) Metropolitan Area Network (MAN) (2) MAN is a network with a size between a LAN and a WAN. A MAN spans the distance of a typical metropolitan city. The cost of installation and operation is higher. MANs use high-speed connections such as fiber optics to achieve higher speeds. Examples of a MAN: 1) part of the telephone company network that can provide a high-speed DSL line to the customer; 47 2) cable TV network. MAN based on cable TV 48 Metropolitan Area Network (MAN) (3) Wide Area Network (WAN) (1) elation between hosts on LANs and the subnet. Metropolitan area network The main differences between WAN and LAN are: - LAN is fully controlled by the owner whilst the WAN needs the involvement of another authority like Telephone Company. - The transfer rate of LAN is higher than the transfer rate of 50 WAN. 8

Wide Area Network (WAN) (2) WAN network spans a large geographical area, it contains a collection of hosts that are connected by a communication subnet.

Subnet consists of transmission lines and switching elements, and its job is to carry messages from host to host.

53 54 Wireless Networks (1) - Users have a dream to connect their notebooks to the network without having to be plugged into a telephone wall socket.

9 Wide Area Network (WAN) (2) WAN network spans a large geographical area, it contains a collection of hosts that are connected by a communication subnet. The Internet is a good example of a WAN. Wide Area Network (WAN) (3) Host is a machine that is used to run user (i.e., application) program and is owned by the customers. Subnet consists of transmission lines and switching elements, and its job is to carry messages from host to host. 51 Wide area network Wide Area Network (WAN) (4) Wide Area Network (WAN) (5) A stream of packets from sender to receiver Wireless Networks (1) - Users have a dream to connect their notebooks to the network without having to be plugged into a telephone wall socket. - To achieve a true mobility there is a need to use a radio (or infrared) signals for communication. Three main categories: 1- System interconnection 2- Wireless LANs 3- Wireless WANs 55 Wireless Networks (2) (a) Bluetooth configuration (b) Wireless LAN 56 9

Wireless Networks (3) - System interconnection, it is about interconnecting the components of a computer using a short-range radio that uses the masterslave paradigm.

10 Wireless Networks (3) - System interconnection, it is about interconnecting the components of a computer using a short-range radio that uses the masterslave paradigm. Example: - Bluetooth is a short-range wireless network that allows digital components to connect to a computer by merely being brought within range. Wireless Networks (4) - Wireless LAN, it is a system where every computer has a radio modem and antenna with which it can communicate with other systems. - Wireless LANs are used in small offices, homes, older office building, conference rooms and other places. - IEEE (WiFi) is a standard for wireless LANs Wireless Networks (5) Wireless Networks (6) - Wireless WAN, it is similar to wireless LAN system, but with lower bandwidth and is used in a wide area systems. - Three generations of Wireless WAN : the first one was analog and for voice only the second one was digital and for voice only the third one is digital and for both voice and data Wireless LAN 59 - IEEE (WiMAX) is a standard for wireless WANs. 60 Home Networks - Every device in the home will be capable of communicating with every other device, and all of them will be accessible over the Internet. - Examples of devices that are capable of being networked: 1- Computers (PC, Notebook, PDA) 2-Entertainment (TV, DVD, Camera...) 3-Telecommunications (telephone, intercom...) 4-Appliances (microwave, refrigerator, lights ) 5- Telemetry (smoke alarm, thermostat, babycam ) 61 The Internet (1) The Internet has revolutionized many aspects of our daily lives. It has affected the way we do business as well as the way we spend our leisure time. The Internet is a communication system that has brought a wealth of information to our fingertips and organized it for our use. History of Internet: Beginning in It was called APANET. TCP/ IP is a protocol suite in the Internet. The main Internet applications are: , News, emote Login, File transfer, World Wide Web (WWW) 62 10

- These backbone networks are connected by complex switching stations (normally run by a third party) called network access points (NAPs).

11 The Internet (2) The Internet (3) - The Internet today is run by private companies, not the government. - The national Internet service providers are backbone networks created and maintained by specialized companies. - These backbone networks are connected by complex switching stations (normally run by a third party) called network access points (NAPs). - Local ISPs can be connected to a regional or national service provider. Hierarchical organization of the Internet 63 - Most end users are connected to the local ISPs. 64 The Internet (4) Networking Standards (1) We define two widely used terms: protocols and standards. First, we define protocol, which is synonymous with rule. Then we discuss standards, which are agreed-upon rules. 65 A protocol is a set of rules that governs data communication; the key elements of a protocol are syntax, semantics, and timing. - The term syntax refers to the structure or format of the data, meaning the order in which they are presented. - The word semantics refers to the meaning of each section of bits. How is a particular pattern to be interpreted, and what action is to be taken based on that interpretation? - The term timing refers to two characteristics: when data should be sent and how fast they can be sent. 66 Networking Standards (2) Networking Standards (3) Standards are necessary to ensure that products from different manufacturers can work together as expected. Advantages of standards A standard assures that there will be a large market for a particular piece of equipment or software. A standard allows products from multiple vendors to communicate. Disadvantages of standards A standard tends to freeze the technology. There are multiple standards for the same thing. 67 Standards are developed through the cooperation of standards creation committees, forums, and government regulatory agencies. The ISO, ITU-T, ANSI, IEEE, and IETF are some of the organizations involved in standards creation. ISO - International Organization for Standardization ITU-T - International Telecommunication Union-Telecommunication Standards Sector ANSI - American National Standards Institute IEEE - Institute of Electrical and Electronics Engineers IETF - Internet Engineering Task Force - Forums are special-interest groups that quickly evaluate and standardize new technologies. - A equest for Comment (FC) is an idea or concept that is a originator to an Internet standard

12 Networking Standards (4) Summary A network consists of two or more entities sharing resources and information. A computer network consists of two or more computers that are connected and are able to communicate. The 802 working groups. The important ones are marked with *. The ones marked with are hibernating. The one marked with gave up. 69 Summary The basic purpose of networks is to enable effective communication, share resources, and facilitate centralized management of data. Networks can be classified according to their geographical boundaries or their component roles. 12

Data Communication. Chapter # 1: Introduction. By: William Stalling

Data Communication. Chapter # 1: Introduction. By: William Stalling Data Communication Chapter # 1: By: Introduction William Stalling Data Communication The exchange of data between two devices via some form of transmission medium such as cable wire. For data communications