Why Understand Networks in an Information System?
An organization’s Information System (IS) includes all the tools, software, data, and hardware needed to manage and deliver information and services.
For everything to work properly, these components must be connected. This connection is made possible by a network.
Think of each computer, server, or smartphone as a person living in a city. The network is like the city’s roads, bridges, and public transport that allow people to communicate, share information, and work together.
Without a network, each device would be isolated and unable to communicate with others.
Understanding networks means knowing how data travels between devices and how this flow is managed to be fast, reliable, and secure.
This knowledge is essential to understand how common IT services—such as email, websites, and databases—actually work.
Whether you plan to be a user, a technician, or just curious, understanding networks is key to grasping how an organization’s Information System functions.
What is a Network?
A network is a collection of devices connected together to share information and resources. These devices can include computers, servers, printers, smartphones, and other hardware. The primary purpose of a network is to enable communication and data exchange between these devices.
Key Concepts:
- Nodes: The individual devices connected to the network (e.g., computers, servers, printers).
- Links: The physical or wireless connections that allow data to travel between nodes (e.g., Ethernet cables, Wi-Fi signals).
Why Do We Use Networks?
Networks allow multiple devices to:
- Share data: For example, users can access shared files or databases.
- Access shared resources: Such as printers or internet connections.
- Communicate: Send messages, emails, or collaborate in real-time.
- Use centralized services: For example, software hosted on servers accessed by many users.
Types of Networks by Scale:
- Local Area Network (LAN): A network covering a small geographical area like a home, office, or building. It connects devices within close proximity.
- Wide Area Network (WAN): A network that spans large distances, such as between cities or countries. The Internet is the largest WAN.
- Metropolitan Area Network (MAN): Larger than a LAN but smaller than a WAN, typically covering a city.
How Does a Network Work?
Networks work by following rules called protocols that standardize communication. The most common protocols are TCP/IP, which manage how data is packaged, addressed, transmitted, and received across networks.
Real-World Example:
Think of a network as a postal system:
- The devices (nodes) are like homes and businesses.
- The links (wires, Wi-Fi) are like roads and delivery routes.
- Protocols are like postal rules ensuring letters are correctly addressed and delivered on time.
Without a network, each device would operate in isolation, unable to share or communicate, greatly limiting functionality.
The Role of the Network in an Information System
The network is the central part of any Information System (IS). It connects all the devices, software, and services so they can work together smoothly. Without a network, the different parts of the system would be isolated and unable to communicate.
Main Roles of the Network:
- Allowing Access:
The network lets users connect to resources they need, like websites, emails, or company files. When you open an app or browse the internet, your device uses the network to reach the right server. - Moving Data:
The network carries information between devices. It makes sure data travels quickly and correctly, whether it’s a small message or a large video. - Keeping Data Safe:
Networks use tools like firewalls and encryption to protect data from hackers and unauthorized access. - Making Services Reliable:
Networks help keep services available all the time. If one server is busy, the network can send requests to another to avoid problems. - Supporting Applications:
Many business tools, like email or cloud storage, rely on the network to work properly. - Helping the System Grow:
Networks make it easy to add more devices, users, or locations without breaking anything.
Types of Networks in a Business Environment
Businesses rely on different network types to connect devices, share resources, and maintain secure and efficient communication. Each type serves a specific role, depending on the scale, purpose, and security needs of the organization.
LAN (Local Area Network)
Definition:
A LAN connects computers and devices within a limited, localized area such as a single office, floor, or building.
Characteristics:
- High data transfer speeds (typically 1 Gbps or higher).
- Controlled and maintained internally by the organization’s IT team.
- Enables resource sharing like printers, files, and applications.
- Usually connected via Ethernet cables or Wi-Fi (WLAN).
Use Cases:
- Office networks connecting employees’ computers, printers, and local servers.
- Campus networks within schools or universities.
Benefits:
- Low latency and high performance.
- Greater security since the network is private.
- Easier to troubleshoot and manage due to small size.
WLAN (Wireless LAN)
Definition:
A WLAN is similar to a LAN but uses wireless connections (Wi-Fi) instead of cables.
Characteristics:
- Provides mobility and convenience to users.
- Typically covers the same area as a LAN but without physical cables.
- Security is enforced via protocols like WPA3.
Use Cases:
- Employees using laptops and smartphones within an office.
- Public Wi-Fi hotspots in cafes or airports.
Benefits:
- Flexibility and mobility for users.
- Quick setup without extensive cabling.
WAN (Wide Area Network)
Definition:
A WAN connects multiple LANs across broad geographic locations — cities, countries, or continents.
Characteristics:
- Uses public or private transmission technologies such as leased lines, MPLS, or the internet.
- Lower data transfer speeds compared to LANs due to distance and link types.
- Requires routing and WAN optimization techniques.
Use Cases:
- Multinational companies connecting branch offices worldwide.
- Banks linking regional branches.
Benefits:
- Enables global connectivity.
- Supports distributed business operations.
MAN (Metropolitan Area Network)
Definition:
A MAN covers a larger area than a LAN but smaller than a WAN, typically a city or metropolitan region.
Characteristics:
- Connects multiple LANs within a city or campus.
- Often uses fiber optic connections for high speed.
- Can be owned by a single organization or service provider.
Use Cases:
- City-wide public Wi-Fi networks.
- University campuses with multiple buildings.
DMZ (Demilitarized Zone)
Definition:
A DMZ is a network segment that separates an internal network from untrusted external networks, such as the internet.
Characteristics:
- Hosts public-facing services (websites, mail servers, VPN gateways).
- Isolates these services from the internal LAN to reduce risk.
- Controlled by firewalls that regulate inbound and outbound traffic.
Use Cases:
- Hosting a company’s public website.
- Allowing secure VPN access for remote employees.
Benefits:
- Adds an extra security layer to protect sensitive internal data.
- Minimizes attack surface on internal networks.
VPN (Virtual Private Network)
Definition:
A VPN establishes a secure, encrypted tunnel over the public internet to connect remote users or offices to a private network.
Characteristics:
- Protects data confidentiality and integrity.
- Uses protocols such as IPsec or SSL/TLS.
- Can connect individual users or entire networks.
Use Cases:
- Employees working remotely connecting securely to the office network.
- Secure site-to-site connections between branch offices.
Benefits:
- Enables secure remote access.
- Protects data from interception on public networks.
SAN (Storage Area Network)
Definition:
A SAN is a dedicated high-speed network that connects storage devices to servers, improving data access and storage management.
Characteristics:
- Uses fiber channel or iSCSI protocols.
- Separates storage traffic from regular network traffic.
- Provides centralized and scalable storage.
Use Cases:
- Data centers managing large amounts of data for critical applications.
- Enterprises requiring fast, reliable access to storage resources.
Cloud Networks
Definition:
Cloud networks rely on cloud service providers to host applications, services, and storage over the internet.
Characteristics:
- Can be public (shared resources), private (dedicated resources), or hybrid (mix of both).
- Managed and scaled by cloud providers like AWS, Azure, or Google Cloud.
- Accessed remotely over the internet.
Use Cases:
- Hosting business applications and data without investing in physical infrastructure.
- Scalable resource use for growing businesses.
6. Basic Network Equipment (Full List)
Switch
Connects multiple devices within a Local Area Network (LAN). It directs data only to the specific device it’s intended for, making communication efficient.
Vendors: Cisco, Aruba (HP), Juniper, NETGEAR, TP-Link
Router
Connects different networks together, such as your company’s internal network to the internet. It directs data packets based on IP addresses and manages routing between networks.
Vendors: Cisco, MikroTik, Ubiquiti, Juniper, DrayTek
Firewall
Protects the network by filtering traffic according to security rules. It blocks unauthorized access and can detect and stop threats.
Vendors: Fortinet, Palo Alto Networks, Sophos, Check Point, Cisco
Access Point (AP)
Allows wireless devices to connect to the wired network using Wi-Fi. Often used in office environments to provide mobility.
Vendors: Ubiquiti (UniFi), Cisco Meraki, Aruba, Ruckus, TP-Link
Modem
Connects your network to the ISP. Converts digital data to signals compatible with internet infrastructure (e.g., fiber, cable).
Vendors: ARRIS, Motorola, NETGEAR, TP-Link, Zyxel
Load Balancer
Distributes traffic across multiple servers to avoid overloading and to ensure high availability.
Vendors: F5 Networks, Citrix NetScaler, Kemp, HAProxy, NGINX
Proxy Server
Acts as an intermediary between users and external services. It can cache data, block sites, and anonymize traffic.
Vendors/Solutions: Squid, Zscaler, Blue Coat, Fortinet, Microsoft TMG (legacy)
IDS/IPS (Intrusion Detection/Prevention System)
IDS monitors and alerts on suspicious traffic. IPS actively blocks it. Often used for network security in real time.
Vendors: Snort, Suricata, Cisco, Palo Alto Networks, Fortinet
Network Interface Card (NIC)
A hardware component that allows a device (PC, server) to connect to a network. Available in Ethernet and Wi-Fi versions.
Vendors: Intel, Realtek, Broadcom, ASUS, TP-Link
Patch Panel
Used in data centers and server rooms to organize and connect multiple network cables cleanly and accessibly.
Vendors: Leviton, Panduit, Tripp Lite, APC, CommScope
Repeater
Extends the range of a network signal by amplifying and retransmitting it. Useful in large physical environments.
Vendors: TP-Link, NETGEAR, D-Link
Hub
Legacy device that connects devices in a LAN but broadcasts data to all ports. Less secure and slower than switches.
Vendors: Generic, mostly obsolete
Bridge
Connects two different LAN segments and manages traffic between them. Rare today; functionality now in switches.
Vendors: Cisco, D-Link, legacy vendors
Media Converter
Converts network signals from one medium to another, such as copper Ethernet to fiber optic.
Vendors: TP-Link, StarTech, Transition Networks
Wireless LAN Controller (WLC)
Manages multiple access points in larger wireless networks — centralizes configuration, security, and firmware updates.
Vendors: Cisco, Aruba, Ruckus
VoIP Gateway
Connects VoIP systems to traditional phone lines (PSTN). Enables voice calls over IP networks.
Vendors: Cisco, Grandstream, AudioCodes
Rack & Enclosures
Physical structures to mount and organize network hardware in server rooms or data centers.
Vendors: APC, StarTech, Rittal, Tripp Lite
Network Tap / SPAN
Used for passive traffic monitoring without interrupting normal data flow — important for diagnostics and security.
Vendors: Garland Technology, Ixia, Cisco
Out-of-Band (OOB) Management Device
Provides remote access to network equipment when the main network is down — ensures continuous management capabilities.
Vendors: Opengear, Lantronix, Raritan
Uninterruptible Power Supply (UPS)
Provides temporary power during an outage to keep network devices online. Protects against sudden shutdowns.
Vendors: APC, Eaton, CyberPower
NTP Time Server
Synchronizes clocks on all devices in the network — essential for logs, security, and certificates.
Vendors: Meinberg, Microsemi, Garmin
Network Infrastructures
In a business environment, the IT infrastructure can be deployed in different ways depending on factors like security, budget, flexibility, and performance needs. There are three main models of infrastructure: on-premise, cloud, and hybrid. Each has its own advantages and trade-offs.
On-Premise Infrastructure
An on-premise infrastructure means that all servers, storage systems, applications, and network equipment are physically hosted within the organization’s building, such as in a server room or private data center. The company is fully responsible for managing, maintaining, and securing this infrastructure.
This model offers full control over data, security policies, and hardware. It does not rely on external providers or internet connections for internal operations. However, it requires significant investment in hardware, power, cooling, physical space, and skilled IT staff.
On-premise is often used in industries that handle sensitive data, such as banking, healthcare, and government.
Cloud Infrastructure
Cloud infrastructure relies on resources hosted in remote data centers and accessed via the internet. These resources are provided by third-party companies like Amazon Web Services (AWS), Microsoft Azure, or Google Cloud Platform (GCP). Organizations rent services such as virtual machines, databases, or storage based on usage.
This model allows businesses to quickly scale, pay only for what they use, and avoid maintaining physical servers. It offers fast deployment, global availability, and strong built-in redundancy. However, it involves giving up direct control over physical infrastructure, and it requires a stable and secure internet connection.
Cloud infrastructure is ideal for startups, mobile apps, and companies with rapidly changing workloads or global users.
Hybrid Infrastructure
A hybrid infrastructure is a mix of on-premise and cloud environments. For example, a business might store sensitive customer data on-premise for compliance reasons but host its public-facing website or collaboration tools in the cloud.
This model combines flexibility with control. Businesses can keep critical systems in-house while using the cloud for non-sensitive services or to handle variable workloads. A well-designed hybrid infrastructure allows for gradual cloud migration, cost optimization, and better business continuity.
However, managing a hybrid setup can be complex. It requires careful planning to ensure security, data synchronization, and network performance across both environments.
8. Network Careers and Their Roles
Entry-Level Roles
Network Technician / Field Technician
Level: Entry
Core Responsibilities: Install and patch network hardware (switches, routers, APs), lay and label cables, configure basic network settings, support users with connectivity issues.
Key Skills: Ethernet standards, IP addressing, cable testing, hardware troubleshooting, basic CLI commands.
Certifications: CompTIA Network+, Cisco CCST.
Career Path: → Network Administrator, NOC Technician.
NOC Analyst / NOC Technician (Network Operations Center – Tier 1)
Level: Entry
Core Responsibilities: Monitor live network status and alerts, triage issues, escalate incidents to higher tiers, generate event tickets.
Key Skills: SNMP monitoring, basic packet captures, dashboard tools (Nagios, Zabbix), log triage.
Certifications: Cisco CCNA, CompTIA Network+.
Career Path: → NOC Tier 2, SOC Analyst, Network Administrator.
Mid-Level Roles
Network Administrator
Level: Intermediate
Core Responsibilities: Configure and maintain LAN/WAN, VLANs, routing protocols (e.g. OSPF), DHCP/DNS, firewalls, and VPNs. Manage network documentation and updates.
Key Skills: TCP/IP, VLANs, packet inspection tools (Wireshark), basic network automation, firewall configuration.
Certifications: Cisco CCNA, CompTIA Security+.
Career Path: → Network Engineer, Security Engineer.
NOC / SOC Analyst (Tier 2)
Level: Intermediate
Core Responsibilities: Analyze escalated alerts, correlate logs across systems, manage incident workflows, perform threat hunting basics.
Key Skills: SIEM tools (Splunk, QRadar), IDS/IPS fundamentals, packet forensics, incident response processes.
Certifications: CompTIA CySA+, Cisco CCNA Security.
Career Path: → Incident Responder, Security Engineer Lead.
Network & Security Engineer
Level: Intermediate–Senior
Core Responsibilities: Design and enforce firewall/VLAN policies, deploy intrusion systems, audit network security, assess risk, and harden infrastructure.
Key Skills: Firewall platforms (Palo Alto, Fortinet), IPS tuning, VPN solutions, NAC, segmentation frameworks.
Certifications: CCNP Security, Fortinet NSE4/NSE5, Palo Alto PCNSE.
Career Path: → Security Architect, Incident Response Lead.
Wireless Network Engineer
Level: Intermediate
Core Responsibilities: Conduct RF site surveys, design Wi-Fi coverage and capacity plans, configure WLAN controllers, troubleshoot interference and user connectivity.
Key Skills: 802.11 Wi-Fi standards, Ekahau or similar surveying tools, WLAN controller systems (Cisco, Aruba).
Certifications: CWNA, Cisco Wireless Specialist.
Career Path: → Wireless Architect, Mobility Consultant.
Advanced-Level Roles
Network Engineer
Level: Senior
Core Responsibilities: Develop enterprise-grade network configurations, implement routing (BGP/OSPF), manage redundancy, QoS, MPLS, SD-WAN. Lead major network projects or migrations.
Key Skills: Advanced routing/switching, network optimization, vendor equipment expertise.
Certifications: CCNP Enterprise, JNCIP-SP.
Career Path: → Network Architect, Data Center Lead.
Network Automation / DevNet Engineer
Level: Senior
Core Responsibilities: Automate network deployment and monitoring, develop configuration pipelines, integrate network APIs and CI/CD practices.
Key Skills: Python/Ansible scripting, REST APIs, Terraform, version control (Git), automation frameworks.
Certifications: Cisco DevNet Associate/Professional, Ansible Certifications.
Career Path: → Infrastructure Automation Specialist, Platform Engineer.
Cloud Network Engineer
Level: Senior
Core Responsibilities: Architect cloud-native networks (VPCs, subnets, peering), enable secure hybrid connectivity (VPN, Direct Connect, ExpressRoute), manage cloud-based routing and security policies.
Key Skills: AWS/Azure/GCP network services, Terraform, cloud-native firewalls, load balancing.
Certifications: AWS Advanced Networking, Azure Network Engineer, GCP Network Engineer.
Career Path: → Cloud Architect, Hybrid Infrastructure Lead.
VoIP / Unified Communications Engineer
Level: Senior
Core Responsibilities: Deploy and manage SIP/VoIP systems, configure QoS for voice traffic, integrate IP telephony with collaboration platforms (e.g. Teams, Zoom), manage PBX systems.
Key Skills: SIP/RTP protocols, codecs, Cisco CUCM, Asterisk, ribbon gateways, QoS settings.
Certifications: CCNP Collaboration, Microsoft Teams Voice, other VoIP certifications.
Career Path: → UC Architect, Collaboration Systems Manager.
Expert-Level Roles
Network Architect
Level: Expert
Core Responsibilities: Set global networking strategy, define architecture standards, manage vendor selections, design networks for multi-site or cloud integration, ensure scalability and high availability.
Key Skills: Enterprise-level design, risk assessment, business-driven architecture, hybrid-cloud networking.
Certifications: Cisco CCDE, TOGAF, AWS/Azure Architect Professional.
Career Path: → CTO, Head of Infrastructure, Enterprise Architect.
Security Architect / Network Security Architect
Level: Expert
Core Responsibilities: Design enterprise-wide secure network frameworks, enforce zero-trust architectures, oversee compliance, threat modeling, and policy governance.
Key Skills: Security frameworks (NIST, ISO 27001), governance, intrusion strategy, network segmentation.
Certifications: CISSP, SABSA, CISM.
Specialized & Cross-Functional Roles
Infrastructure Engineer (Network-Focused)
Level: Intermediate–Senior
Core Responsibilities: Oversee networking within full-stack infrastructure deployments, including virtualization (e.g., VMware NSX), SAN/NAS, VLAN, and hybrid cloud setups.
Key Skills: Hypervisor networking, SAN/Fibre Channel, VLANs, data center operations.
Career Path: → Infrastructure Architect, Hybrid Systems Lead.
IT Generalist with Network Focus (SMB)
Level: Generalist
Core Responsibilities: Manage overall IT infrastructure in small or mid-sized organizations—covering networking, servers, user support, and endpoint management.
Key Skills: Active Directory, VPN, DHCP/DNS, basic scripting, troubleshooting.
Certifications: CompTIA A+, Network+, MCSA or equivalent.
Telecom / ISP Network Engineer
Level: Specialist
Core Responsibilities: Design and maintain large-scale ISP or carrier-grade networks, manage BGP routing, MPLS, traffic engineering, and interconnections.
Key Skills: Peer relationships, high complexity routing protocols, capacity planning, QoS optimization.
Certifications: Cisco CCIE Service Provider, Juniper JNCIP-SP.
Career Path: → ISP Core Architect, Telecom Infrastructure Lead.
9. Summary and Conclusion
The network plays a central role in any Information System, connecting all devices, services, and users. Understanding the basics of networking is essential because it helps you grasp how information moves, how systems communicate, and how services work together securely and efficiently. This foundation is important for learning more advanced topics and for working effectively with IT systems in the future.