--- title: Number of SSIDs and Airtime description: Minimize SSIDs to reduce Wi-Fi overhead, optimize airtime, and enhance security with NAC, RBAC, or MPSK. Improve network efficiency without excessive SSIDs --- [Skip to content](https://help.sidos.com/choosing-the-correct-number-of-ssids#main-content) English Show submenu for translations [More support](https://help.sidos.com/kb-tickets/new) [![Sidos](https://help.sidos.com/hs-fs/hubfs/social-suggested-images/www.sidos.comwp-contentuploads202303sidos-logo-white.png?width=120&height=36&name=www.sidos.comwp-contentuploads202303sidos-logo-white.png)](https://help.sidos.com/) Open main navigation Close main navigation - English Show submenu for translations - [More support](https://help.sidos.com/kb-tickets/new) - [Sidos Cloud](https://app.sidos.com/) [Sidos Cloud](https://app.sidos.com/) Sidos Help Center - There are no suggestions because the search field is empty. 1. [Sidos Help Center](https://help.sidos.com/) 2. [Blog](https://help.sidos.com/blog) # Number of SSIDs and Airtime With complex networks, IoT devices, and nearly everything imaginable now able to connect to Wi-Fi, the practice of mapping an SSID to a single VLAN is becoming outdated. Traditionally, whenever data needed to be separated on a wireless network, a new SSID had to be created. Each SSID would then be mapped to a single VLAN, and the VLAN would be routed internally as required. Having multiple SSIDs, each mapped to a single VLAN, **led many organizations to create numerous SSIDs**. I have personally seen a single AP broadcasting **14 SSIDs**. ### **Why Is Adding More SSIDs a Bad Idea?** Each additional SSID increases **management overhead**. Wi-Fi, like all wireless technologies, has a **fixed amount of airtime** that must be efficiently managed. At a certain point, the management overhead of multiple SSIDs **consumes more airtime** than the actual data traffic, reducing overall network efficiency. #### **Beacon Frames and Airtime Usage** A **beacon frame** is sent out **every 102.4 milliseconds per SSID**. These frames broadcast: - The **SSID name** - The **security parameters** supported by the SSID - The **basic and supported data rates** Since beacon frames must be **heard by all potential clients**, they are transmitted at the **lowest supported data rate**: - On **2.4 GHz**, beacon frames are sent at **1 Mbps**. - On **5 GHz**, beacon frames are sent at **6 Mbps**. This means that **every 100 milliseconds (10 times per second)**, clients must **pause their operations** to listen for beacon frames from every SSID in range. ### **The Impact of Excessive SSIDs** As discussed, excessive SSID overhead can bog down even the most well-designed network. - If a single AP is broadcasting multiple SSIDs, the impact may be minimal. - However, **when multiple APs broadcast the same excessive number of SSIDs, airtime utilization can be consumed quickly**. For a detailed breakdown, see this chart from Wi-Fi Professionals: [SSIDs Overhead Effect on Channel Utilization](https://www.wifi-professionals.com/2018/08/ssids-overhead-effect-on-channel-utilisation). ![](https://help.sidos.com/hs-fs/hubfs/image-png-Aug-05-2024-01-21-37-1750-PM.png?width=688&height=513&name=image-png-Aug-05-2024-01-21-37-1750-PM.png) #### **The Solution: VLAN Segmentation Without Excessive SSIDs** To solve this problem, **traffic must be segmented** while ensuring each SSID remains secure. This is where **Network Access Control (NAC)** comes in. A **NAC system** does the following: 1. **Authenticates users and devices** based on a predefined list. 2. This list can be: - **Manually generated** - **Tied to Active Directory roles** - **Dynamically assigned** based on various factors This method, known as **Role-Based Access Control (RBAC)**, allows VLANs to be assigned based on user roles rather than relying on separate SSIDs. > **Is This Too Complex for Small Networks?** > Not really—similar access control models have existed for **file permissions in Active Directory** for decades. In fact, Novell NetWare had a similar system in the **1990s**. #### **Example: Role-Based VLAN Assignment** Let’s consider a company with **two SSIDs**: 1. **Corporate SSID** using **802.1X authentication** 2. **Guest SSID** with a splash page Here’s how it works: - A **corporate user** enters their credentials. - The **RADIUS server** (typically tied to Active Directory) verifies them. - A properly configured **NAC system** assigns the device to the correct VLAN **automatically**. - **Access Control Lists (ACLs)** can then be used to **restrict communication between VLANs**, enhancing security—especially for **IoT devices**. #### **Alternatives: MPSK and iPSK** If **NAC or 802.1X** is not an option, some vendors offer: - **MPSK (Multiple Pre-Shared Key)** - **iPSK (Individual Pre-Shared Key)** These work like traditional PSKs but allow multiple unique PSKs within a **single SSID**. ### **How This Helps** - Each **PSK is assigned a role** in the system. - The **controller maps roles to VLANs**. For example: - **User with PSK1 → VLAN 92** - **User with PSK2 → VLAN 96** This allows for **VLAN segmentation while using only one SSID**. While most implementations are **based on WPA2**, vendors are working on **WPA3-compatible** versions. #### **Key Takeaways** ✅ **Limit networks to 3 SSIDs or fewer** whenever possible. ✅ **Manage airtime wisely**—more SSIDs mean more airtime wasted on management traffic. ✅ **Use proper channel planning** to avoid interference. ✅ **Ensure AP power settings** are optimized for efficient coverage and minimal overlap. - [Getting started](https://help.sidos.com/getting-started#main-content) - [Accounts & Sharing](https://help.sidos.com/getting-started#accounts-sharing) - [Wave & Mobile App](https://help.sidos.com/getting-started#wave-mobile-app) - [Accessories and Mounting](https://help.sidos.com/getting-started#accessories-and-mounting) - [Buildings and Projects](https://help.sidos.com/buildings-and-projects) - [Surveys, Planner and More](https://help.sidos.com/surveys-planner-and-more#main-content) - [Sidos AI](https://help.sidos.com/surveys-planner-and-more#sidos-ai) - [AP on a Stick (APoS)](https://help.sidos.com/surveys-planner-and-more#ap-on-a-stick-apos) - [Survey](https://help.sidos.com/surveys-planner-and-more#survey) - [Deep Survey](https://help.sidos.com/surveys-planner-and-more#deep-survey) - [Planner](https://help.sidos.com/surveys-planner-and-more#planner) - [Micro Apps](https://help.sidos.com/micro-apps) - [Reporting](https://help.sidos.com/reporting) - [Troubleshooting Guides](https://help.sidos.com/troubleshooting-guides) - [Release Notes](https://help.sidos.com/release-notes) - [Blog](https://help.sidos.com/blog) - [Community](https://help.sidos.com/community) [![Sidos](https://help.sidos.com/hs-fs/hubfs/Sidos%20Logo_black.png?width=120&height=52&name=Sidos%20Logo_black.png "Sidos")](https://www.sidos.com/) sidos.com Help Center Copyright © 2026, Sidos Systems