TLDR
‘Ping’ is the informal term for the time taken to transmit a piece of information between two computers on a network or over the internet.
Ping vs Latency
Ping, latency, and RTT (Round Trip Time) all refer to different aspects of the same thing - the time it takes a single ‘packet’ of information to traverse a segment of a network (between two computers or devices) and then get back again, usually stated in milliseconds (ms).
Why is ping important?
Ping can directly affect certain internet activities - most notably gaming traffic, but also voice traffic and other types of time-sensitive applications.
Data can travel down a wire as light, radio waves or electrical signals. Whichever medium the signal uses, it still has to follow the basic laws of physics and can’t exceed the speed of light in that medium.
Because of this, there will always be a minimum ping depending on geographic distance - generally, the latency adds up by around one millisecond per 100 kilometres. This matters because on very long links (such as those to other continents) throughput (how much data can be transmitted at a time) will decrease while ping increases, as both ends have to wait longer to ‘acknowledge’ receipt of a packet of data before sending more.
Does using a VPN affect ping?
If your objective is to reduce latency, then using VPNs is often not advisable, as traffic first has to get to the VPN server, then exit onto the internet, then take the whole way back - often adding much additional latency and overhead.
How is ping measured?
The usual method of determining latency is by using a built-in program called ‘ping’ on one of the two computers or devices that you want to measure latency between. The program sends a single packet of information - known as a ‘ping echo request’ packet - to the other computer, which replies back with a ‘ping echo reply’ packet. The ping program measures the time it took for that reply to arrive back.
The result of that measurement is known as the latency, and it’s a measurement of the RTT (round-trip-time) between the two computers.
When performing a ping test, it’s important to understand that because the ping packet has to travel between every point in between you and the other host, the measurement is a reflection of the latency across every single point along the way.
If any single part of the entire path is introducing additional latency, you’ll see that reflected in the total trip time.
Partly for this reason, another tool called ‘traceroute’ can often be used to help troubleshoot latency issues - this tool does its best to measure the ping at every step along the way as well as traffic is passed from network to network. This is a great way to figure out if the additional latency is occurring at a specific point in your network - for example in your Wi-Fi network, in your provider’s network, or somewhere else, after the traffic leaves your provider’s network.
Are speed tests a good indicator of ping?
Speed tests are a reasonable way to get an idea of ping, but with a few caveats.
Firstly, just like the ‘ping’ program, speed tests only measure the ‘end to end’ latency between your device (the one being used to perform the speed test) and the speed test server, wherever it is in the world. That means that there are many more points along the path where additional latency and bottlenecks can be introduced, which can skew the final results.
Secondly, most browser-based speed tests are only able to measure latency by sending certain types of traffic over the network and that can sometimes make the results a bit wonky, because the traffic is passed through or handled by many different ‘layers’ of your PC and network devices.
Although important, ping is just one way of measuring the performance of a network connection. Another is ‘jitter’.
Jitter
Jitter is a measurement (also in milliseconds) of the variation between a series of ping tests. Jitter can also be a handy tool in understanding network performance, as significant jitter can indicate that a problem is occurring somewhere.
Did you know: The most common cause for jitter is Wi-Fi
Although latency is a physical property, a variation in latency can sometimes be caused by a link somewhere along a path reaching its capacity. When this happens, devices along the way have to add the packet to a ‘buffer’, storing it temporarily until it can continue along. In other cases, the packet might be lost, and have to be re-sent. This is primarily what causes effects like jitter in a network.
Bufferbloat & Packet Loss
In this way, latency can also be affected by heavy use on your home network, which causes parts of the network to bottleneck. For example, if you were downloading a large game update, your link might become full, leaving no room for gaming traffic. Because there is no room that gaming traffic has to wait in line before it can be sent, adding latency (the technical definition here is ‘bufferbloat’), jitter and/or packet loss.
Who's responsible for ping? Me or my internet service provider?
If you are experiencing high latency, packet loss or jitter, first rule out any internal factors that might be introducing the problem (like Wi-Fi bottlenecks, or an over utilised connection). Your ISP can also help you do this, but ultimately, resolving any internal issues are always your responsibility.
How does ping affect online gaming?
If you’re serious about your online gaming, you’ll want the latency to be as low as possible. Higher latency than your opponents can make you lose your competitive edge in fast-paced FPS or RPG games.
Nowadays, it’s common for games to have some solid techniques to counteract the effects of players with differing amounts of latency, but this will vary game to game.
While high latency is undesirable, a real killer for online gaming is jitter. Where a game’s developers may be able to employ some tricks to compensate for several players with different (but consistent) latencies, jitter (which is just inconsistent latency) is much harder to code workarounds for.
To minimise jitter, make sure your PC or console is using a cabled-in connection - save the Wi-Fi for the phones and tablets. You’ll also need to make sure there’s nothing on your network (like a big game update) that might be using up all the capacity of your connection.
What can my ISP do to reduce ping?
As mentioned earlier, data can travel as light, as radio waves or as electrical signals. Regardless of the medium in use, data still has to follow the basic laws of physics.
This means that there are absolute minimum times for data to travel from, say your PC in Perth to the gaming server in Sydney, and generally speaking there isn’t anything your ISP can do about this type of latency.
From time to time, a provider may run new cables between two locations and may take a different geographic path or use a technology that offers a minor improvement in latency.
When this happens, providers have a choice over which path to take when they want to send traffic between locations.
While troubleshooting and eliminating issues inside of your home is your responsibility, it’s the responsibility of the ISP to make sure that they are utilising the best available paths for traffic to take (establishing and maintaining direct peering relationships where possible) and effectively operating their network in a way that prevents bottlenecking or congestion (including trying to work around those issues if they occur elsewhere on the internet).
What services give the best ping?
When selecting game servers, select the region closest to you. Basic guidelines for last-mile ping times across various services:
- FTTN/HFC NBN: 5-10ms
- FTTP nbn™: 1-5ms
- Fixed Wireless: 10-20ms
