Introduction to Technology Infrastructure Chapter 1 Introduction to Technology Infrastructure

Announcements and Outline Class Outline 1.Introduction to Networks 1.1 Network Types/Technologies 1.2 Layering and Packetization 2

Why Networks are Important Data, data, data! Modern organizations rely on the efficient transmission of data Enables distributed systems, real-time communication, electronic commerce, social media, and the Web

Data Communications Data Communications is the movement of computer information from one point to another by means of electrical or optical transmission systems Telecommunications is a broader term and includes the transmission of voice and video (images and graphics) as well as data and usually implies longer distances

Basic Network Components Client is a user device to access network and receive data from server e.g., desktops, laptops, tablets, cell phones, etc. Server is a device that stores and transmits data to a client e.g., Web server, mail server, file server Circuit is a pathway or connection between client and server e.g., copper wire, fiber optic cable, wireless

Network Types/Technologies 6

Network Types/Technologies Local Area Networks (LAN) Wireless Local Area Networks (WLAN) Backbone MAN WAN 7

Network Layers Most Commonly Used Models: OSI (Open Systems Interconnection Reference Model) Network Model Protocols & Protocol Data Unit (PDU) 8

Network Layers (Network Model) 9

Network Layers – Packetization Packetization is breaking down user data into small segments packaging these segments appropriately so that they can be delivered and reassembled across the network *From Agarwal – Business Data Communications 10

Network Layers – 5 Important Data Comm. Tasks

Network Layers APPLICATION LAYER Software used by the users Common Examples: Protocols: PDU: 12

Network Layers TRANSPORT LAYER End to end management Responsibilities: (1) Link Applications Layer Segmenting and Tracking Session Management 13

Network Layers TRANSPORT LAYER (cont.) Protocols: PDU: 14

Network Layers NETWORK LAYER Decides where the messages should go Functions: Addressing Routing Protocol: PDU: 15

Network Layers DATA LINK LAYER Moves messages from one computer to the next Functions: Controls Hardware Formats Messages Error Checking Protocol: PDU: 16

Network Layers PHYSICAL LAYER Hardware that transmits the message Protocols: PDU: 17

Network Layers - Summary Purpose Example Protocols / Standards PDU 5. Application User’s access to network, software to perform work HTTP, SMTP, DNS, FTP, DHCP, IMAP, POP, SSL Packet (or Data) 4. Transport End-to-End Management Link application layer to network Segmenting and tracking Flow control TCP, UDP Segment 3. Network Deciding where the message goes Addressing Routing IP, ICMP Packet 2. Data Link Move a message from one device to the next Controls hardware Formats the message Error checking Ethernet Frame 1. Physical Transmits the message 100BASE-T, 802.11n 18

Sender PDU Receiver HTTP Request HTTP Request TCP HTTP Request TCP Application Packet Transport Segment Network Data Link Frame Physical HTTP Request HTTP Request TCP HTTP Request TCP HTTP Request IP TCP HTTP Request IP IP TCP HTTP Request Ethernet Ethernet IP TCP HTTP Request Ethernet IP TCP HTTP Request

Network Layers Standards IEEE (Institute of Electrical and Electronics Engineering) – develops US standards Formal Standardization Process Internet technology standards are publicly available as Requests For Comment (RFCs) http://www.ietf.org/rfc.html Highly recommended standards Email: http://www.ietf.org/rfc/rfc0821.txt HTTP: http://www.ietf.org/rfc/rfc2616.txt TCP: http://www.ietf.org/rfc/rfc0793.txt IP: http://www.ietf.org/rfc/rfc0791.txt TCP/ IP tutorial: http://www.ietf.org/rfc/rfc1180.txt Domain names: http://www.ietf.org/rfc/rfc1034.txt 20

Pros and Cons of using Layers Advantages: Disadvantages: 21

Trends Bring your own device (BYOD) Internet of Thing (IoT) Massively Online (MOOCS)

Recap Network Types 1.1 Network Types LAN WLAN Backbone WAN 1.2 Network Layers Network Model Standards Pros/Cons 23

Tuesday Chapter 2 – Application Layer Hardware Software Architecture Web Email 24