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Ping, Lag & Latency



Ping is a useful tool, but not for measuring internet speed.

Many people (even specialists) use ping to measure speed. But it measures network latency, a completely different property that should not be confused with with bandwidth, throughput, or surfing speed.

Bandwidth
The maximum amount of raw data that can be transmitted per second. It's a fixed property, calculated rather than measured. In a network the bandwidth is the highest speed of the slowest component.
Throughput
The actual data that is transmitted per second. Only the payload data is counted, not any overhead such as start/stop bits, TCP/IP, or HTTP overhead. Throughput depends on things like bandwidth, latency, payload size, packet size, network load, number of hops, and others.
Latency
The minimum time a network needs to send the smallest possible amount of data. Latency depends on things like line speed and the receive and retransmit delay in routers and modems. A low latency indicates a high network efficiency.

Ping was originally developed to probe a target machine and see if the network towards it is functioning correctly. It will send a very small ICMP packet (usually 8 bytes, plus the standard TCP/IP and ICMP overhead) to the target, which responds with a similarly minimal packet. The target and the network do not have to do much work, so the round-trip usually takes mere milliseconds. When you receive the reply you know that both the target and the network are alive and well. Ping will measure the time it takes for the round-trip. A pure latency measurement would only measure the one-way delay, ping measures there-and-back delays together.

Traffic on the internet like Nova Game is much larger (kilobytes and more) than ping traffic , is often split in several chunks, servers must perform real work (like fetching an image from hard disk), and the protocols are quite different (HTTP, SMTP, FTP, etc.). Many providers have optimized their routers for Ping, which obviously doesn't do anything for regular internet traffic. Another difference, more subtle, is that users jump all over the place. The internet is a complex collection of fast and slow networks, so ping measurements between two points say nothing about other stretches on the information highway.

So why is everybody using Ping? Well, Ping has been around for a long time and everybody knows it. It's very easy to use, just a single command. Ping has been ported to just about every operating system and is included as a standard component, so it's free and it's readily available. Building Ping into other programs is almost trivial, it's very small and basic. Other programs for measuring the speed of the internet exist but are more difficult to get, install, use, and understand.

Traceroute is a derivative of Ping and uses the same technology. It was developed as a tool for network administrators to pinpoint problems in a network. Traceroute will send ping-packets to all the individual routers between the source and the target. The replies are listed and show exactly which router is causing problems. Measurements based on Traceroute do exactly the same as Ping, they simply measure round-trip times. Tabulated and averaged this provides valuable information for network administrators, but is most definitely not a speed measurement.

Lag can be caused by many factors, slow computer, poor quality video card, slow connection to the internet or one that takes too many HOPS for the packets to get to their destination. In fact some packets can be taking different routes to get to their destination once broken down by their particular protocol. So to reduce lag time, get a fast internet connection and a gamming system with a fast CPU, Chipset, Video Graphics Adapter, and that is tweaked, (Like SiG :) ) , Dells, Gateways, HP, e.g. are not gamming systems they are low end systems built for maximum profit and not maximum performance, so expect Lag if you are using any of their systems.

So the next time you are on a game server like Nova and are arguing about ping times, just remember Nova doesn't send simple 8 byte ICMP packets and Ping is not used to measure SPEED.

Charles,

www.sigfl.net