High Availability in Home Office

Introduction

This article was created in response to numerous emails and questions, demonstrating how to build a high-availability system in a home environment. The timeliness of this writing comes from my own experiences: since March 4, 2025, we have been struggling with packet loss and intermittent internet service, and on April 16, 2025, there was a complete internet service outage in the entire Haller Street 23-25 building with the Digi Kft/One provider.

As my friends often say: "Those who know you know what they're getting, those who don't know you don't know what they're missing." So now I'm showcasing the high-availability system I use, which can be applied to any home office and home environment - even in extreme situations when the main internet provider isn't performing adequately.

Since CSE Business Kft.'s headquarters is also located in the affected building, and internet is a critical service for us, I apply exactly the same backup solutions at home/in my home office that we use in our business to ensure continuous operation.

Why are backup solutions = redundancy / high availability important

Many people know that I consider high availability and elimination of "single points of failure" extremely important in IT operations (OT), business continuity, and disaster recovery (BCDR). This includes various B-plans that help when the primary solution doesn't work. Throughout my more than 25 years of IT and OT professional experience, my principle has always been that there is no room for compromise in critical systems: security, continuity, and availability are paramount.

Our current situation - more than 7 weeks of struggling with internet service problems at Haller Street 23-25 - perfectly demonstrates why building redundant systems is vital in both home and corporate environments. An internet service outage is not just an inconvenience but can cause serious work disruption, missed deadlines, and significant business losses.

In the following, I won't mention specific brands, but I can say that we use exactly the same solutions that we recommend to CSE Business Kft.'s partners (our clients). Yes, we consider our customers as partners, and we ensure high availability and elimination of "single points of failure" in all three of our main service areas: IT consulting, IT services, and IT support.

Professional systems for companies and home offices alike

1. Implementing a modern firewall in home environment

Let's start with the basics: in my home work environment, I use a premium category, modern firewall with cloud-based monitoring. The firewall's power supply is provided by a UPS (uninterruptible power supply) - this is the first redundant, risk-reducing solution that guarantees power supply even during power outages, fuse blowouts, or phase failures. Many underestimate the importance of a firewall in a home office, yet it's one of the most important basic elements.

In apartment buildings (such as at Haller Street 23-25), internet service problems frequently occur, affecting both residents and companies operating there. The current internet service problem that has lasted more than 7 weeks and the complete service outage on April 16 particularly demonstrate how important it is to build redundant systems - whether working from home or from a company headquarters.

We cannot know exactly what services other companies operating in Haller Street 23-25 use and how they overcome this problem, but based on my own experience, I'm sharing how to build a truly reliable system that guarantees continuous work even in similar situations.

2. Setting up alternative internet connection in the home office

The next potential source of failure is the internet service being shut down by the provider. This could be a building-wide issue or the provider's internet connection being suspended - in short, when there is no service on the wired cable, but our own devices are working.

In such cases, a second internet connection becomes vital in the home office - one that is not cable-dependent and preferably not power-dependent either.

The firewall I use can handle two internet connections - this is now a basic functionality in models intended for home use as well. Although firewalls generally can handle a second or even third internet/WAN line, and can be set up with built-in SIM cards or eSIMs, I use a separate device that is SIM card-based and can also distribute Wi-Fi. This device provides the second internet connection to the firewall via cable.

3. Mobile internet as a backup solution for home work

Why did I choose a second device of this kind? I connected it to a second UPS, and it's also portable - if I go to a conference or training, I simply put it in my bag. It has now been proven that this device is worth every penny in a home office, as the current internet problem is not constant but rather intermittent, and the source of the error is difficult to identify. The packet loss experienced since March 4 and the complete outage on April 16 clearly demonstrated that a redundant solution is not a luxury but a necessity.

From my laptops that I work on, I simply switch to this Wi-Fi network and can continue working immediately - this flexibility is invaluable when working from home.

Regarding the service: I use a completely unlimited mobile package, supplemented with the MultiSIM service. The provider offers multiple SIM cards for the MultiSIM service, so one of the MultiSIM cards is in the "backup" device. Over the past period, we've generated several hundred GB of data traffic on this backup connection, as the main internet service became unusable for many important tasks - such as downloading and uploading SharePoint files.

4. Optimizing Wi-Fi infrastructure in the home office

For complete coverage of the home work environment, I use a separate Wi-Fi device (from the same manufacturer as the firewall), which provides wide/high coverage Wi-Fi network at every point in the apartment. This is especially important if you work in multiple rooms, or if family members also use the network while you're holding an important video conference (a separate article will be written about this later).

Benefits of a high-availability home office system in practice

In the table below, I summarize the possible risks in a home office environment, the corresponding solutions, the potential "single points of failure," and how we bridge these problems:

As the events of recent times show (beginning of packet loss problems on March 4, 2025, and complete service outage on April 16 at Haller Street 23-25), building a professional home office system is not a luxury but a necessity for uninterrupted work.

Lessons and recommendations for home office setup

The more than 7-week-long internet service problems, especially the complete outage on April 16, 2025, at Haller Street 23-25 building, have highlighted several important lessons that can be useful for setting up any home work environment:

1. Never rely on a single provider in a home office environment. Always have a Plan B, especially if internet connection is essential for your work. Our current situation perfectly proves that this is not paranoia but reasonable precaution.
2. It's worth investing in a mobile internet-based backup solution, even if it initially seems more expensive. The technology and infrastructure of cable and mobile internet are completely different, so the chance of both failing simultaneously is extremely small. This is especially important for deadline-driven or critical work.
3. Modern versions of firewalls intended for home use already support multiple WAN connections by default. Take advantage of this feature and configure the automatic switching appropriately. A proper firewall not only increases security but also enables flexible connection switching in the home work environment.
4. UPSs are not luxury expenses but essential in a home office. It's worth connecting both our own devices and provider equipment (if possible) to these. An average UPS provides 30-60 minutes of uninterrupted work during a power outage, which can be enough to save or even complete work.
5. Setting up proper Wi-Fi infrastructure is also part of the home office redundant system. Don't skimp on quality Wi-Fi devices, especially in larger apartments or houses where you might work in multiple rooms. Stable Wi-Fi connection also significantly improves the quality of video conferences.
6. Develop a regular data backup strategy. Regular backup of data created during home work (preferably to multiple locations) is essential. Follow the 3-2-1 principle: 3 copies, on 2 different types of media, with 1 physically located elsewhere.
7. Keep spare devices ready. If possible, have a secondary computer that can take over the role of the main system if needed. This could even be an older laptop that is kept up-to-date and synchronized with the main workstation.

As my friends often say: "Those who know you know what they're getting, those who don't know you don't know what they're missing." This principle also applies to home office setup: those who have experienced similar service outages know how valuable a truly high-availability home work environment is - those who haven't may now learn how much inconvenience and financial loss they can save themselves with proper preparation.

I hope the above information helps understand why and how it's worth building a redundant internet connection system in a home environment as well, especially when the main internet provider becomes unreliable. The presented solutions not only provide convenience features but are essential for ensuring uninterrupted work and productivity.

At CSE Business Kft. and in my own home office, I apply exactly the same solutions that we recommend to our clients - as we all face the same challenges, whether working in an office or at home. The events of the recent period have only strengthened my conviction that the investment in high-availability systems pays off multiple times when it's most needed.