session one

Internet of Things (IoT)

• Aims to connect all devices to the existing internet infrastructure
• Enables devices with sensors to collect and send data to the internet
• Examples of devices: coffee maker, AC, washing machine, ceiling fan, lights
• Practical applications: smart homes, smart cities, energy management, environment monitoring, healthcare

Transport Layer

• TCP (Transmission Control Protocol): • Reliable (acknowledgement) • Connection-oriented (synchronization) • Full duplex • Error control (error checking with checksum) • Data-recovery features • Used for: e-mail, file sharing, downloading
• UDP (User Datagram Protocol): • Unreliable (best-effort delivery) • Connectionless (no notification) • Full duplex • Performs very limited error checking • No data-recovery features • Used for: voice streaming, video streaming

Transport Layer Addressing (Port Numbers)

• Port numbers controlled by ICANN
• Well-known ports are permanent and used for specific services

Network Access Layer

• Physical Layer: • Defines electrical, mechanical, and transmission medium • Responsible for moving individual bits from one node to the next
• Datalink Layer: • Provides logical interface between end system and network • Error notification (frames, media access control) • Hop-to-hop addressing • Error detection mechanism (detects damaged or lost frames)

Physical Addresses (MAC)

• Burned on the network interface card (NIC)
• Unique address worldwide
• 48-bit (6-byte) address written as 12 hexadecimal digits
• Separated by a colon (:) between each byte
• Types of physical addresses: unicast, multicast, broadcast

Internet/Network Protocol Layer (IP Layer)

• Provides connectivity and path selection between two hosts
• Routing of data between independent networks
• Logical addressing using IPv4 and IPv6

Internet Protocol (IP V4)

• Uniquely identifies each device on an IP network
• Low speed
• Under ISP administrative control
• Example of a WAN (Wide Area Network) is the Internet

Internet

• Defined as a global mesh of interconnected networks
• No single owner of the Internet
• Multiple organizations, ISPs, companies, and governments own pieces of Internet infrastructure
• Organizations involved in Internet governance: ISOC, IETF, ICANN

Network Models

• Peer-to-Peer Networks: • No dedicated resources • Easy to work with • All nodes are equal
• Client-Server Networks: • Dedicated nodes (servers) provide services to other nodes (clients) • Server is more powerful • Examples of servers: mail server, web server, file server, print server

Protocols

• Why we need protocols: • To communicate efficiently • To enable data flow from one NIC to another • To control messages and message quantity in the network
• OSI Reference Model: • Defined by ISO in 1983 • Provides universal concepts for developers • Breaks down the approach into layers

TCP/IP Protocol Suite

• Transmission Control Protocol/Internet Protocol
• Open standard protocol
• Cross-platform (default protocol for modern operating systems)
• Not tied to one vendor
• Direct access to the Internet
• Routable
• TCP/IP is the internet protocol (currently using v4, with v6 as the next version)