Health & Metric Flashcards
What are Health & Metric analysis?
They are about spotting trends and patterns in data collected from network traffic monitoring. The identified trends and patterns can then be used to proactively introduce traffic management methods to keep the network healthy. Traffic management methods can ensure that the capacities on network devices are maximized without overloading them thereby
increasing the return on investment or ROI. Metric analysis involves measuring
key performance statistics to understand how something is performing and
predict its future performance based on the gathered data. Tools used for this prediction generally need at least 30 days worth of data to create a baseline performance.
How do you determine network health and performance?
For a network, there are several different metrics that can help determine network health and performance. Let’s examine some of them. First is bandwidth usage. This metric is about checking that you are not going over the amount of available bandwidth. If the bandwidth usage is too high, it can affect the network’s performance by slowing things down. The second metric is packet loss. When packets get lost on the network between the source and destination, you know that TCP can re-send those lost packets. But that can actually create more congestion on the network if it occurs too often. The third is latency. This is how long a packet takes to move across the network and back again. It’s also known as the round trip time or RTT. Last is network availability. This is a key metric because it reflects up time on the network. In other words, it tells you when the network is working and when it is not. These metrics and others can tell you how healthy your network is and how well it’s performing.
How does a network manage its performance?
By utilizing something called Quality of Service or QoS. QoS is a suite of different traffic management mechanisms that can be used at different times based on network performance. Although traffic monitoring is ongoing, traffic management mechanisms should only be turned on when needed. If everything works as it should, you don’t need to create extra work. Two of the mechanisms included in QoS are traffic marking and prioritization. Traffic marking allows you to mark packets with for example, different colors to indicate priority. For example, real-time information like video calls should be prioritized. Less critical traffic, like email can be given a low priority.
