[Glossary](https://telxpress.com/glossary/) / Network # VLAN A **VLAN** (virtual local area network) splits one physical network into separate logical networks, so that phones, computers, guest Wi-Fi, cameras and building systems are kept apart for security and performance without separate cabling. - Network - Updated October 11, 2026 - Written by the Telxpress advisory team 01 In depth ## What it is, why it matters and *what to ask a vendor* VLANs are defined in IEEE 802.1Q, which adds a tag to Ethernet frames so switches know which logical network each belongs to. A typical office runs a voice VLAN for phones, a data VLAN for staff computers, a guest VLAN for visitors' Wi-Fi, and a separate VLAN for cameras and door controllers, with the firewall deciding what may pass between them. For a growing business VLANs are the simplest way to stop one problem becoming everyone's problem: a visitor's infected laptop cannot reach the finance server, a camera with a weak password cannot see the phone system, and voice traffic gets its own lane for QoS. They also make compliance conversations easier, because regulated systems sit on a network you can describe. Ask whoever designs your network which VLANs they propose and why, how traffic between them is controlled at the firewall, how phones and access points are placed on the right VLAN automatically, and how the design is documented. Ask what happens when a device is plugged into the wrong port, because that is how most segmentation quietly fails. 02 Related terms ## Terms that usually come up *alongside it* - Network ### [Firewall](https://telxpress.com/glossary/firewall/) A firewall is the security device or service that inspects traffic entering, leaving and crossing your network and allows or blocks it by rule, protecting your systems from the internet and from each other. - Network ### [QoS (quality of service)](https://telxpress.com/glossary/qos/) Quality of service (QoS) is the network configuration that identifies time-sensitive traffic such as voice and video and gives it priority over downloads and backups, so calls stay clear when the network is busy. - Network ### [PoE (Power over Ethernet)](https://telxpress.com/glossary/poe/) Power over Ethernet (PoE) delivers power to devices such as phones, Wi-Fi access points, cameras and room controllers through the same network cable that carries their data, so no outlet is needed at the device. - Network ### [Wi-Fi 6, 6E and 7](https://telxpress.com/glossary/wi-fi-6-6e-7/) Wi-Fi 6, 6E and 7 are the most recent generations of wireless networking; each handles more devices in a crowded office with less delay, and 6E and 7 add the less congested 6 GHz band. 03 At Telxpress ## Where this shows up *at Telxpress* The pages and articles where this term does real work: what we advise, build and support. - Page ### [Business Networking, Firewalls & Managed Wi-Fi](https://telxpress.com/solutions/business-technology/networking/) Switching, routing, Fortinet firewalls, Ubiquiti and Cisco Meraki Wi-Fi and managed network services for offices that depend on reliable connections. - Page ### [Business Surveillance Cameras & Access Control](https://telxpress.com/solutions/business-technology/surveillance/) IP cameras from Hikvision, access control and monitoring designed for your site, installed and supported locally with your network and phones. - Article ### [Fortify Your Enterprise: Best Practices for a Secure Business Network](https://telxpress.com/insights/fortify-your-enterprise-best-practices-for-a-secure-business-network/) The layered network security practices that hold up in real offices, from patching and MFA to Wi-Fi hardening, tested backups and an incident plan, including the phone system. 04 Sources ## Public *references* The standard or law this definition rests on, as published by its owner. Fetched and checked on the review date above. - [IEEE 802.1Q-2022, Bridges and Bridged Networks](https://standards.ieee.org/ieee/802.1Q/10323/) standards.ieee.org Next step ## Want This Applied *to Your Business?* Book a free 30-minute AI readiness consultation. You'll leave with three AI opportunities specific to your business, whether you work with us or not. [Book My Free Consultation](https://telxpress.com/book/) [Take the Free AI Readiness Assessment](https://telxpress.com/ai-readiness/) [Or call 24/7: (949) 861-4500](tel:+19498614500) Last reviewed: October 11, 2026. Published by Telxpress, Irvine, CA.