What is Uptime and Downtime?

Quick Definition: Uptime refers to the amount of time devices on the network are reachable, while downtime refers to the time devices aren’t reachable, indicating something is wrong. 

When it comes to networking, availability is everything. When one or more devices on the network are “down,” money is lost, customers become frustrated, and security gaps form. In networking, the amount of time a system is functional and “on the network” is referred to as uptime.

Conversely, the amount of time one or more devices are unreachable is referred to as downtime. The goal of successful network engineers is to have (way) more uptime than downtime. 

In this article, we will discuss the significance of uptime and downtime in networking and the factors influencing them. We will also discuss some methods to ensure more uptime and look at some ways to recover when we do experience downtime. Finally, we will explore some ways to monitor uptime and downtime. 

What is the Significance of Uptime and Downtime in Network Operations?

For users, downtime might mean not being able to browse their favorite social media app or buy something on Amazon right this second. However, for your favorite social media sites and Amazon, downtime can mean millions and potentially billions in lost profit during the period of downtime. 

The significance of uptime cannot be overstated, as one site being unavailable can result in a chain reaction of negative consequences. Let’s say your favorite travel booking site pushes an update to production and accidentally brings down its site.

For starters, if they rely on an MSP (Managed Service Provider) to help maintain their site, that MSP may be responsible for some negative consequences due to Service Level Agreements (SLAs), resulting in financial penalties and reputation damage. 

Next comes the impact on the businesses relying on making sales via that site. Hotels aren’t booking rooms because their customers can’t reach the site. Airlines aren’t booking passengers.

Rental cars aren’t being reserved. Customers become frustrated, and clauses within business agreements start coming into question. Companies can measure lost profits with relative accuracy, but it’s more challenging to quantify the damage to reputation, and reputations take longer to recover than devices.

All of this to say—downtime isn't just a minor inconvenience, it can have major business implications. 

What Factors Affect Uptime and Downtime?

Thankfully, many of the factors affecting uptime and downtime can be controlled or at least accounted for when planning your network. Let's look at the main factors to keep in mind when trying to reduce downtime: 

Hardware and Software 

Newer, reliable hardware, especially when coupled with compatible and reliable software, will help network engineers maintain optimal uptime. However, the older and more worn-down your hardware is, the more likely you’ll run into issues. Similarly, a tech stack consisting of various, only semi-compatible software will likely run into problems once one or more components receive an upgrade that renders another part of the stack incompatible. 

Network Design 

Another influencing factor is the network itself. Networks built with redundancy in mind will fare better than those built without. To increase your organization’s chances of maintaining network availability, you will want to include things like failover devices and load balancers in your plans. 

You’ll also want to ensure your firewall rules are not so restrictive as to block necessary traffic from traversing the network appropriately. This ties into the next factor, human error. 

Human Error 

Human error is one of the most common and preventable causes of network downtime. Mistakes can range from pushing untested code to production to misconfigured firewall rules that block critical traffic. In IT environments, even a tiny oversight—like mistyping a command or forgetting to update dependencies—can lead to cascading issues that disrupt services.

While human error is inevitable, it can be minimized through proper training, thorough documentation, and robust processes like automated testing, change management, and peer reviews.

Environmental Disasters 

Finally, no amount of training can outmatch the raw power of environmental disasters. AWS’s US-East-1 and US-East-2 locations are in Virginia and Ohio, respectively. Both locations are relatively safe from destructive weather events like tornadoes, hurricanes, flooding, and earthquakes. 

While both areas can experience hot summers, cold winters, and blizzards, fluctuating temperatures only threaten access to power. In contrast, the previously mentioned weather phenomena threaten the overall structural well-being of facilities such as data centers and office buildings. 

When planning your network, consider whether your network equipment will be exposed to environmental risks. If so, it may be worth investing in hosting a backup somewhere with less environmental activity.

How to Monitor Uptime: Tools and Preparation 

Now that we understand just how crucial uptime is, let’s explore monitoring and alerting tools. Most devices will provide at least basic performance monitoring capabilities to help troubleshoot issues, and of course, paid tools like: 

• Nagios 

• DataDog 

• SolarWinds  

The size and complexity of your network and your budget will determine the tools you use. The more you spend, the more detailed information you will have at your disposal. Most of the paid tools even offer capabilities to fix the issue right from within the tool itself, so long as it’s not a physical issue with a device. 

These tools look at metrics and statistics like throughput, latency, and packet loss to determine whether the network is running normally or if it’s experiencing some issues. This information should help you identify the problem’s point of origin, which then allows you to work on identifying the root cause. 

Ideally, whatever tool(s) you’re using will alert you to issues before you or your customers experience them, giving you a chance to fix any issues before it gets too bad. Depending on which tools you’re using, you may be able to receive automatically generated tickets based on a device or network performance metric reaching specific criteria. Some criteria could include metrics such as 10% or greater packet loss or a specific latency threshold.

Of course, these are reactive measures. You should be performing proactive activities to help mitigate network issues altogether. Some of these activities can include upgrading hardware and software when necessary, stress testing systems to ensure things like backup systems and automatic alerts are working properly, and general checkups to confirm your network’s baseline is still accurate.

How to Mitigate Downtime

The best way to mitigate downtime is to be proactive. These steps should all be built into your network design and contingency plans: 

• Redundancy: In the field of networking, two is one, and one is none. What this means is that redundancy is key to ensuring network uptime. Redundancy is achieved by implementing failover systems wherever you think they might be appropriate. 

• Load balancers: These will help direct traffic evenly across two or more devices, and backup servers and databases will help ensure there’s a spare from which to recover should one become unreachable.

• Have a plan: Having spares is not enough. You also need to have a plan to utilize those spares. Having a Disaster Recovery Plan, a Business Continuity Plan, and an Incident Response Plan will not only help your network recover quickly but also ensure your organization is compliant with various frameworks such as SOX and PCI.  What does your organization consider an acceptable recovery time, often referred to as a Recovery Time Objective (RTO) or Meantime to Repair (MTTR)?

Knowing how to respond to these issues step by step is crucial. Know how to respond, when to respond, and what roles need to be involved. Your organization should be conducting tabletop exercises to evaluate preparedness and effectiveness, making adjustments when necessary.

What are the Best Practices for Maximizing Uptime and Minimizing Downtime?

You can maximize your network’s uptime by keeping a few principles in mind: Design and implement network architectures with high availability in mind. We’ve mentioned redundancy a few times so far, but that’s genuinely what it takes to maintain a high-availability environment. This includes backups and failover systems, as well as capturing incremental backups so you’re never working without too much of the data you should have. 

It's also essential to maintain your equipment. Ensure your hardware is well maintained, and all software receives regular updates. This also includes ensuring your equipment is in good physical condition, such as undamaged cables and proper cooling and ventilation around servers. 

Finally, benchmark your network’s performance at regular intervals. The only way you can detect network issues early is by knowing how your network normally behaves.

Conclusion

Uptime is critical to smooth business. Uptime means you can make sales, communicate with your customers, and perform the work you do best. Without uptime, your business risks its reputation, its customer satisfaction, and overall ability to make money. 

Thankfully, several tools, both free and paid, can help you monitor and repair your network’s performance. Overall, network architecture can also improve network uptime. By planning with network redundancy in mind, you can help prevent single points of failure in your environment. 

If you want to learn more, check out the CBT Nuggets High Availability Online Training with Knox Hutchinson course.