Have you ever thought how you could analyze the quality of your network service? Or how good is your network? Probably, many times. It merely implies that you want to measure the performance of your network connection.
So, what is Network Performance? Network performance refers to measures of service quality of a network as seen by the end-user. Network speed is sometimes synonymous with the performance of a network.
However, the metrics that help in determining the overall performance are bandwidth, latency, throughput, jitter, and error rate.
The data transmission rate is usually in bits per second and kbps, Mbps, Gbps are the units for measuring the performance rate of this transmission.
Let’s get a closer look at how can you measure network performance and explore in detail the factors that affect it.
What does Network Performance mean?
An informal, practical approach to a definition of network performance is to determine the speed of the network.
The primary function of a network is data transmission from one point to another. Therefore, you can say that how fast this data travels, i.e., speed is an essential characteristic of any network.
Although, speed is a good network performance benchmark, but is it everything? The answer is a definitely No.
The capability of a network to carry transactions that include the transmission of large volumes of data, as well as supporting a considerable amount of concurrent operations, is also part of the overall network performance.
What factors affect Network Performance?
Several factors affect the performance of a network. They are usually called metrics.
Let’s find out each of them, one by one.
Bandwidth is the data-carrying capacity of a network or data transmission medium. It is the theoretical maximum, raw data rate that can pass through a communications channel.
Bit/second is the measurement of bandwidth. It refers to the maximum amount of data that can travel from one point to another in a unit of time.
For example, a lack of bandwidth can result in data waiting in a queue before being transmitted, which makes an application run slower.
Latency is the total time in which a data passes from one designated location to another across a network. It is sometimes also known as a delay.
Latency is specified in Milliseconds and is a measure of the time taken by a packet to reach its intended destination. It is an important measurement to express the expected responsiveness of a network connection.
Some standard functions like loading a web page are less sensitive to latency than others such as real-time gaming or VoIP calling. It results in a noticeable delay in both gameplay and conversation, respectively.
Throughput refers to the actual maximum observed rate that data travels across a network or processing system. It is the number of messages successfully delivered per unit time.
The available bandwidth impacts the throughput, along with the available signal-to-noise ratio and hardware limitations.
Lets say that one Ethernet network has a transmission rate of 100 Mbps. That means the absolute upper limit on throughput is 100mbps, even though in general it could be less.
The terms bandwidth and throughput are often used interchangeably, even though they are not the same.
Jitter is variation in latency of packet at the receiving end of the information. It indicates the uneven delay in the delivery of audio or video packets.
You can measure Jitter in Milliseconds.
It happens due to network congestion, timing drift and route changes. It causes choppy and less than real-time voice or video communication, buffer underruns, and generally poor performance.
The error rate refers to the number of corrupted bits expressed as a percentage or fraction of the total sent.
It merely means that some received bits of a data stream altered due to noise, interference, distortion or bit synchronization errors.
It refers to packets that don’t make it to their intended destination intact, or at all. It generally occurs across the open internet than within the context of a LAN.
Different units to measure Performance rate of a Network
Data travels along a network link in the form of “bits,” or individual on and off signals. It is transmitted serially, which means one bit at a time. Modern networks support enormous transfer numbers of bits per second.
Instead of writing speeds of 10,000 or 100,000 bps, networks normally express per second performance concerning kilobits (Kbps), megabits (Mbps), and gigabits (Gbps), where:
- 1 Kbps = 1,000 bits per second
- 1 Mbps = 1,000 Kbps
- 1 Gbps = 1,000 Mbps
Network connections are typically rated in “megabits,” Slow network connections have speed rate in kilobits, faster links in megabits, and high-speed connections in gigabits.
Examples of Performance measurements in Kbps, Mbps, and Gbps
Almost all network equipment using Kbps is outdated and provides low-performance by today’s standards.
Below you can find some common usage of Kbps, Mbps, and Gbps in computer networking:
- Standard dial-up modems have transmission rates up to 56 Kbps.
- In case of home networks using an 802.11g Wi-Fi router speed is rated at 54 Mbps. On the other hand, new 802.11n and 802.11ac routers are rated at 450 Mbps and 1300 Mbps, respectively.
- The traditional Ethernet has a transmission rate of 10Mbps, while a Fast Ethernet rates up to 100Mbps.
- The Gigabit Ethernet has a transfer rate approaching 1 Gbps.
- A typical encoding rate of MP3 music files is 128Kbps and 320Kbps.
The speed ratings of Internet services vary greatly depending on the kind of Internet access technology and also the choice of subscription plans.
Bits vs bytes. Are they same?
A bit is standard terminology to illustrate network data speeds. However, some people are more perceptive of the file transfer rate over the network which is in bytes, not bits.
If you want to convert a value from bits to bytes, divide it by eight as one byte = 8 bit. For example, a one megabit connection is approximately 1,000,000 bits per second but only 125,000 bytes per second.
Now, you could be thinking how to recognize the difference between a bit and a byte?
It is simple. If it is an uppercase ‘B,’ then it is a byte, and a bit is a lowercase ‘b.’ For instance, if it says MB, all capitals, then it is a megabyte. If it says Mb, then it is a megabit.
There is one exception to this, of course, and it is the symbol for kilobit, which is ‘kb,’ all lowercase. This “b” and “B” creates tremendous confusion sometimes.
When you notice speed ratings, you will find that they are in bits, not bytes. For instance, Fast Ethernet functions at 100 megabits per second, not megabytes.
But in the case of throughput measurements, both bits and bytes are used, so you need to be careful. Raw throughput values are typically in bits per second, but many software applications demonstrate transfer rates in bytes per second.
How can you test Network Performance?
Now that you are aware of what to look for when analyzing a network’s performance, the question arises, how do we measure them?
You can utilize numerous successful network management and measurement tools and examine their ability to provide valuable measurements.
Basic approaches to measuring Network Performance
There are two basic approaches to measuring network performance.
The first is the passive approach in which you can measure the network performance without causing any hindrance to its operation. The idea is to first gather management information from the active elements of the network using a management protocol. Then using this information makes some inferences about network performance.
The second approach is known as an active approach. In this, you inject test traffic into the network and analyze its performance. After that, you need to compare the performance of the test traffic with the performance of the net in carrying the standard payload.
Network administrators utilize several tools to analyze the bandwidth of network connections. In the case of LANs (local area networks), these tools include netperf and ttcp.
Any layman can also detect the bandwidth using the different bandwidth and speed test programs available for free online.
Even if you have an idea about these tools, bandwidth utilization is difficult to measure in exact terms. It might change over time depending on the hardware configuration plus characteristics and usage of software applications.
You can measure your network connection’s latency using the “ping” tool.
Ping forwards a packet to the destination, and waits for a response, calculating the round-trip time and calculating connection latency in ms. It also averages the results of several pings over time for you.
Make sure that you test lag multiple different times, and both on an idle network and a busy network to understand how network load can affect latencies.
If the measured latency is much higher than the theoretical latency, this means there is a problem. You can expect small delays, more so if you are traversing the open internet. Good ping times are below 100ms.
Jitter is slightly more complicated to measure than pure throughput or latency. The data packets that get buffered, queued and switched around a network cause small delays that amalgamate and result in jitter.
You can measure jitter by comparing send and receive timestamps on pairs of packets transmitted. The techniques to estimate are inter-arrival histograms, capturing and post-processing, such as reviewing packet captures, or the deployment of tools that measure jitter in real-time.
Measuring Error Rate
You can observe and monitor error rate measurement during the rest of the testing steps by regularly finding the switch, router, and single interface error counts.
If you want to perform direct testing of error rate, then you have to reset or note the current value of the error rate counters at the send and receive origins. You also need to do this on any network equipment in between those endpoints that you monitor.
You can use a network simulator when testing the intricacies of the large, complex networks that exist today.
After the testing is complete, and you have addressed the problems that arose, you get baseline measurements for all network performance metrics.
Monitoring the network for anomalies and substantial deviations from these baseline measurements will confirm that your network is running at peak performance.
Final thoughts on measuring Network Performance
A network is a quite good example of the classic “Weakest Link” theory. This theory states that the slowest link in the chain determines the speed of the entire chain, or network, in our case.
The data that you acquire from a Network Performance Analysis is vital to building both a network’s baseline attributes as well as to find its limits. In short, it ensures that the network delivers the same quality of service for which you are paying.
Nowadays, the user experience is the key. That’s why measuring the network performance from an end user’s perspective is essential. The client perspective depicts how well all the parts and pieces of network work together to deliver a service to the end user, regardless of network type.