IT 520 Module 1 and 2 Prep

Peer-to-Peer (P2P) Network

A network model where each computer can act as both a client and a server; devices share files and resources directly without a central server.

Client-Server Network

A network model where clients request services or resources from centralized servers that manage access and control.

Advantages of Client-Server Model

Centralized management, scalability, better security, and data backup control.

Advantages of Peer-to-Peer Model

Simple setup, inexpensive, and ideal for small networks.

Purpose of OSI Model

A conceptual framework that standardizes the functions of a communication system into seven layers to ensure interoperability.

OSI Layers (Bottom to Top)

Physical, Data link, network, transport, Session, Presentation and Application

Purpose of OSI

A conceptual framework that standardizes the functions of a communication system into seven layers to ensure interoperability.

OSI Layer 7 - Application Layer

Interface for network applications; provides network services to end users (e.g., HTTP, FTP, SMTP).

OSI Layer 6 - Presentation Layer

Formats and encrypts data; ensures compatibility between systems (e.g., encryption, compression).

OSI Layer 5 - Session Layer

Establishes, manages, and terminates sessions between applications.

OSI Layer 4 - Transport Layer

Manages data transfer and reliability (TCP/UDP); segmentation, sequencing, and error checking occur here.

OSI Layer 3 - Network Layer

Handles logical addressing and routing of packets (IP, ICMP).

OSI Layer 2 - Data Link Layer

Responsible for physical addressing (MAC addresses) and error detection on frames (Ethernet).

OSI Layer 1 - Physical Layer

Transmits raw bit streams over a physical medium; includes cables, switches, and NICs.

OSI Layers (Top to Bottom)

Application, Presentation, Session, Transport, Network, Data Link, Physical

TCP/IP Model Layers

Application, Transport, Internet, Network Access

Difference between OSI and TCP/IP Models

OSI has 7 layers, TCP/IP has 4; TCP/IP is a practical model used in real networks.

Transport Layer Protocols

TCP (connection-oriented) and UDP (connectionless).

Switch

Connects devices on the same network and forwards frames using MAC addresses.

Router

Connects multiple networks and forwards packets using IP addresses.

Hub

Broadcasts data to all connected devices; slower and less secure than a switch.

Bridge

Divides a network into segments to reduce traffic.

NIC (Network Interface Card)

Hardware component that connects a computer to a network.

Access Point (AP)

Provides wireless connectivity to wired networks.

Modem

Converts digital signals to analog and vice versa for communication over telephone lines.

Firewall

Monitors and filters incoming/outgoing network traffic based on security rules.

Electrical Safety

Always unplug equipment before servicing; avoid static discharge by grounding.

ESD (Electrostatic Discharge) Prevention

Use anti-static wrist straps, mats, and grounding techniques.

Cable Management

Label and route cables neatly to prevent damage and confusion.

Lifting Safety

Lift heavy equipment with your legs, not your back

Fire Safety

Use Class C fire extinguishers for electrical fires.

Labeling and Naming Conventions

Standardized labels and names help technicians quickly identify devices, cables, and ports for maintenance and troubleshooting.

Good Labeling Practices

Use clear, permanent, and consistent labeling for cables, ports, racks, and rooms.

Four Types of Software Changes

Major, Minor, Emergency and Standard

Major Change

Large, complex updates such as OS upgrades, new software systems, or structural redesigns.
Requires documentation and possibly downtime.

Minor Change

Small updates like patching or bug fixes; minimal impact and downtime.

Emergency Change

Unplanned changes to fix critical issues (like outages or security flaws).

Standard Change

Routine, low-risk updates that follow a predefined process (like password policy updates).

Logical Network Diagram

Shows how devices connect logically (IP addressing, routing, VLANs).

Physical Network Diagram

Shows actual hardware layout and cable connections.

Rack Diagram

Displays placement of network devices within racks.

Network Map

Gives an overview of all connected devices and links.

Change Management Log

Tracks system modifications, updates, and responsible personnel.

Wiring Diagram

Shows pin layouts and cable connections (for copper/fiber).

Rack Unit (RU)

A measurement for rack-mounted equipment (1U = 1.75 inches tall).

Patch Panel

Organizes and connects cables from various devices in one central panel.

Switch Rack

Holds switches that interconnect network devices.

Cooling and Power

Essential for maintaining optimal temperature and avoiding equipment failure.

HVAC (Heating, Ventilation, Air Conditioning)

Maintains proper temperature and humidity in network rooms

UPS (Uninterruptible Power Supply)

Provides temporary power during outages.

Fire Suppression

Gas-based systems (not water) are used in data centers.

Horizontal Cabling

Runs between workstations and the IDF

Backbone Cabling

Connects MDFs and IDFs across floors or buildings.

Labeling Standards

Follow ANSI/TIA/EIA standards for consistency.