Building a Small Office Network from Scratch: A Component Checklist
Setting up a network for a new small office can be daunting if you do not have a clear plan. From the internet connection to the last cable run, every component needs to work together to deliver reliable connectivity, security, and performance. This guide walks through every layer of a small office network, explains what each component does, and provides a practical checklist so nothing gets overlooked.
Step 1: Internet Connection and Modem
Everything starts with the internet connection. For a small office with 10 to 50 users, you will want a business-grade fibre connection with a guaranteed service level agreement (SLA). Consumer-grade NBN plans may suffice for very small offices, but they lack the uptime guarantees and support responsiveness that a business connection provides. Your internet service provider (ISP) will typically supply a modem or network termination device (NTD). In many cases, this device should be configured in bridge mode so that your firewall handles all routing and security, rather than relying on the ISP's consumer-grade modem.
If your business is critical and cannot tolerate downtime, consider a secondary internet connection (e.g., a 4G/5G failover link) that your firewall can automatically switch to if the primary connection drops.
Step 2: Firewall and Router
The firewall sits between your internet connection and your internal network. It inspects all incoming and outgoing traffic, blocks malicious connections, and enforces access policies. For a small office, a Unified Threat Management (UTM) appliance is ideal because it combines firewall, intrusion prevention, content filtering, VPN, and often SD-WAN in a single device. Popular options include Fortinet FortiGate, WatchGuard Firebox, Sophos XGS, and for budget-conscious setups, Ubiquiti UniFi Security Gateway or Dream Machine. Make sure to select a model whose throughput rating matches your internet speed with all security features enabled, as enabling deep packet inspection significantly reduces throughput on undersized hardware.
Step 3: PoE Switch
A Power over Ethernet (PoE) switch is the central hub that connects all your wired devices and powers devices such as wireless access points, IP phones, and security cameras over the same Ethernet cable. When sizing a switch, consider the number of ports you need today plus at least 30 percent headroom for growth. A 24-port Gigabit PoE+ switch is a common starting point for small offices. If you plan to run multiple VLANs (for example, separating voice, data, and guest traffic), choose a managed or smart-managed switch that supports 802.1Q VLAN tagging.
Do not confuse the number of PoE ports with the total PoE power budget. A 24-port PoE+ switch might advertise 24 PoE ports but only have a 195W total budget, which is not enough to deliver full PoE+ (30W) to every port simultaneously. Calculate your actual power draw before purchasing.
Step 4: Wireless Access Points
Consumer Wi-Fi routers are not suitable for office environments. Instead, deploy enterprise-grade wireless access points (APs) managed through a central controller (hardware or cloud). One AP per 20 to 30 users is a rough starting point, but the actual number depends on floor area, wall materials, and device density. Mount APs on the ceiling for optimal coverage, and use a site survey tool (or at minimum, a floor plan overlay) to identify dead zones. Ensure each AP is fed by a dedicated Ethernet run back to the PoE switch.
Step 5: Structured Cabling
Good cabling is the foundation of a reliable network. Use Cat6 or Cat6A cable for all new runs. Cat6 supports 10 Gbps over short distances (55 metres) and 1 Gbps to the full 100-metre Ethernet limit. Cat6A supports 10 Gbps to the full 100 metres, future-proofing your investment. Run cables in conduit or cable tray where possible, terminate them at a patch panel in a lockable comms cabinet, and label every cable at both ends. Investing in quality cabling at fit-out saves enormous troubleshooting time later.
Run at least two data points to every desk position, even if you only need one today. Adding cables after the walls are sealed is far more expensive than running extra during the initial fit-out.
Step 6: Server or NAS for File Sharing
Even with cloud storage solutions like OneDrive and SharePoint, many small offices benefit from a local file server or NAS (Network Attached Storage). A NAS provides fast local access to large files (architectural plans, video editing projects, design assets) without relying on internet bandwidth. A 4-bay NAS from Synology or QNAP with drives configured in RAID 5 or RAID 6 offers a good balance of capacity and redundancy. For offices that need Active Directory, DNS, and DHCP, a small tower server running Windows Server or a hypervisor is more appropriate.
Step 7: UPS for Critical Equipment
An Uninterruptible Power Supply (UPS) protects your critical network equipment (firewall, switch, NAS, server) from power outages and voltage fluctuations. At a minimum, connect your comms cabinet to a line-interactive UPS with enough battery capacity to keep devices running for 15 to 30 minutes, giving you time to perform a graceful shutdown. Calculate your total load in watts, add 20 percent headroom, and select a UPS rated accordingly. Brands such as CyberPower, APC, and Eaton are popular in the Australian market.
Step 8: VoIP Phone System
Most small offices have moved to Voice over IP (VoIP) for their telephony. A cloud-hosted PBX (such as 3CX, Microsoft Teams Phone, or a hosted provider) eliminates the need for on-premises telephony hardware. You will need PoE-powered IP desk phones at each workstation and a reliable network with Quality of Service (QoS) policies to prioritise voice traffic. If you are using a PoE switch, ensure the power budget accounts for every phone (typically 5 to 15 watts each).
Step 9: Surveillance Cameras
IP surveillance cameras are increasingly standard in office fit-outs for security and safety. PoE-powered cameras connect directly to your network switch, and footage is recorded to a Network Video Recorder (NVR) or to the NAS if it supports surveillance station software (Synology Surveillance Station is a popular choice). Place cameras at entry and exit points, reception, server room, and car park. Ensure your PoE budget and switch port count accommodate all cameras, and run camera traffic on a separate VLAN for security.
Step 10: Network Documentation
Once everything is installed and configured, document it. Create a network diagram showing all devices and their IP addresses, a port map for each switch, a VLAN assignment table, firewall rule summaries, Wi-Fi SSID and password records, and warranty and support contract details for each device. Store this documentation in a secure, accessible location (an IT documentation platform or, at minimum, a shared folder with restricted access). Good documentation is invaluable when troubleshooting issues or onboarding a new IT provider.
Do not store network passwords in a plain-text spreadsheet on a shared drive. Use a proper password manager or IT documentation platform with role-based access control to protect sensitive credentials.
Frequently Asked Questions
Plan for at least two data points per desk (one for the computer, one for the phone), plus ports for access points, printers, cameras, and the server/NAS. For 20 desks, that is roughly 40 desk ports plus 10 to 15 infrastructure ports, so a 48-port switch or a pair of 24-port switches is appropriate.
Not necessarily. If all your files, email, and applications are cloud-hosted, you may not need an on-premises server. However, a small NAS is still useful for local file caching, surveillance recording, and backup storage. Some organisations also keep a small server for on-premises Active Directory, DHCP, and DNS.
Add up the wattage of all devices in the cabinet (switch, firewall, NAS, patch panel is passive so zero watts). A typical small comms cabinet draws 200 to 400 watts. A 1500VA / 900W UPS will keep that load running for approximately 15 to 20 minutes, which is usually sufficient for a graceful shutdown.
Yes. Even in a small office, separating voice, data, guest Wi-Fi, and surveillance camera traffic onto different VLANs improves both security and performance. It prevents guest devices from accessing internal resources and ensures voice traffic gets priority.
In Australia, structured cabling should be installed by a licensed cabler to comply with ACMA regulations. A professional installation also comes with a warranty on the cable plant and ensures proper termination and testing, which prevents intermittent faults that are notoriously difficult to diagnose.
