Data Communication and the Cloud - Chapter 6 Study Notes

Global Communications

• Connects the world, enabling communication across vast distances.

The Ultimate of Data Communications

• Unified Communications.

What Is a Network?

• Telecommunication system: Enables data transmission over networks.

• Network: A system linking computers for communication and resource sharing.

  • Establishes protocols for interoperability.

• Types of Networks:

  • Local Area Network (LAN): Computers connected at a single site.

  • Wide Area Network (WAN): Connects LANs over broader locations.

  • The Internet: Network of Networks.

Simplified End-to-End Network

• Components: NICs, hubs, switches, routers, modems, ATM switches facilitating data transfer.

Where the "Data" in Data Communication Lives

• Data centers equipped with power backups, cooling, security, connectivity, and server racks.

Components of a LAN

• Network Interface Card (NIC): Connects devices to a cable.

• Switch: Transmits messages to computers in the LAN.

• Media: Physical connection (UTP copper wires or fiber optic cables).

Typical Arrangement of a LAN in a Building

• Includes computers, switches, UTP/optical fiber cables, and access points.

Combination of NICs and WNICs on a LAN

• IEEE 802.3 (Ethernet) protocol: Used by wired LAN devices.

• IEEE 802.11 wireless protocol: Uses wireless NICs (WNIC).

• IEEE creates network protocols and standards.

Personal Computer Internet Access

• Typical Modems: DSL or Cable modems.

• ISP (Internet Service Providers): Provide Internet addresses and gateway access.

Secure Networks for Businesses

• Virtual Private Networks (VPNs): Create private connections over the Internet.

How Encryption Works

• Encryption: Transforms clear text into coded text.

  • Symmetric encryption: Uses the same key.

  • Asymmetric encryption: Uses different keys.

• HTTPS: Secure protocol.

• Secure Socket Layer (SSL): Combines public/private key encryption.

Public Key / Private Key Encryption

• Process: Key pair creation, encryption with public key, decryption with private key.

Purpose of a Firewall

• Firewall: Prevents unauthorized network access.

Voice over IP (VoIP)

• Voice over IP (VoIP): Transmits voice calls over the Internet.

IPTV (Internet Protocol Television)

• IPTV: Transmits video signals using TCP/IP.

What Makes The Network Work?

• Protocol: Standard for data format and transmission rules.

• Interoperability: Ability of different systems to share data.

Transmission Control Protocol/ Internet Protocol

• TCP/IP provides the foundation for the Internet (FTP, SMTP, HTTP, HTTPS, SNMP).

IP Addresses

• IP address identifies devices on a network.

• IPv4 is the current format (limited addresses).

Internet Address Space

• IPv6 uses 128-bit addresses.

Public IP Addresses and Domain Names

• IP Address: IPv4 or IPv6 notation.

• Domain name: Example: sjsu.edu.

• URL: Example: http://www.sjsu.edu.

Domain Registrar Company

• Companies facilitate domain registration (e.g., GoDaddy.com).

Typical 3-Tier Web Server Processing

• User Tier, Server Tier, Database Tier.

Cloud Computing

• Shared computer resources over a network with scalability and pay-per-use pricing.

The Cloud: Future for Most Organizations

• Pooled resources, elastic leasing.

Reasons Businesses Use the Cloud

1. Better Insight and Visibility.

2. Easy Collaboration.

3. Support for Business Needs.

4. Rapid Development.

5. Proven Results (cost reduction, efficiency, mobility).

Why Now?

• Technology supports data centers; cheap processors and storage; Moore's Law.

When Does the Cloud Not Make Sense?

• When physical control is required; use private cloud or in-house hosting.

Three Fundamental Cloud Types

Who Manages the Infrastructure?

• Responsibility shifts from user to vendor (On-Premises -> IaaS -> PaaS -> SaaS).

Wireless Media

• Carries signals without wires (IrDA, Bluetooth, Zigbee, WiFi, WiMax, Satellite).

Wireless Devices Changing Business

• Wireless LANs, cellular phones, peripherals, WiMax, GPS, Wireless Sensors.

Cellular Technology

• Cells with base stations.

Bluetooth

• Short-range wireless technology.

Radio Frequency Identification

• RFID uses tags to store and relay information to readers.

Supply Chain Management Using RFID

• RFID used extensively.

Global Positioning System (GPS)

• Determines location using satellites.

Geographic Information System (GIS)

• Framework to capture and analyze spatial data.