gaming ping

[BTRY B 529th FA BN]

A ping to a game server is not based for the majority on the type of connection you are on e.g. cable, dsl, etc. but the rtt, correct?

 

[theevilsharpie]

By rtr, I assume you mean router? (This isn't Twitter, you can post the full word here.)

Then no, most routers don't add an appreciable amount of latency unless they're overloaded. Your connection type, the amount of oversubscription on your your ISP's upstream links, and the distance to the server will have more influence over your overall latency than anything on your local network.

 

[Fardringle]

The only reason your connection type or router would have any effect on the ping time is if you have a really slow ISP or malfunctioning router. Any router that is functioning correctly will add a negligible amount to ping times, and the connection type itself has no effect on pings except where they add a considerable distance to the total connection (such as satellite). When everything is working properly, the only things that have any effect on PING time are distance between you and the host, and load/response time of the hops (Internet routers) between you and the the destination, or if you are overloading your own connection with torrents or other heavy traffic.

 

[BTRY B 529th FA BN]

Sorry I meant round trip time, RTT

 

[Gryz]

RTT is influenced by 3 major factors.

1) Propagation Delay. This is basically the distance. The speed of light seems fast. But it isn't. Speed of Light through vacuum is 300000 km/sec. Speed of light through glass (fibre) is 0.6x of that. So that is 180 km per millisecond. And then RTT is round trip time, so the time is actually doubled. E.g. RTT from East Coast to West Coast = ~ 3000 miles = 4800 km = divided by 180 = 26.7 milliseconds times 2 = an minimum RTT of 53 ms. Europe to West Coast is easily 140 ms.

2) Transmission delay. Internet routing does "store and forward". Suppose you send a packet from A via B to C. When A starts to transmit bits, B will receive the bits in the same order. It keeps storing those bits in a buffer, till all bits are received. Then B will look at the header, decide where to send it next, and start forwarding the packet bit by bit. But it will not start sending the packet to C unless it has receive everything from A. This waiting for the packet to be fully received introduces a little delay. At every hop.

With current Internet speeds, this transmission delay hardly matters. Most packets sent over the net are max 1500 bytes long. Suppose we're talking about a 10 Gbps link (which isn't uncommon these days in ISP networks), the time between receiving the first and the last bit of 1500 bytes is in the order of only a microsecond (a 1000th of a millisecond). This microsecond is nothing compared to the delays introduced by the slow speed of light.

In the "good old days", this was different. People had 33.6k modems, or 56k modems. When using a 33.6k speed line, the time between the first bit and the last bit of a 1500 byte packet would be 33.5 / (1500 * 8) = almost a 3rd of a second ! Gaming packets are usually smaller than 1500 bytes, but still .... Suppose a gaming server sent you a 150 byte packet, the transmission delay would still be 30 milliseconds on 33.6k modem ! Going to a 56k modem would reduce that delay to 21 ms. But still, 22 (extra) ms on your ping in a shooter makes a lot of difference.
But when we start talking about DSL and cable, with speeds of 1 Mbps or higher, those transmission delays drop down to a millisecond or less. Nowadays, the speed of your connection hardly has an impact on your overall ping.

3) Queuing delays. The path between your PC (or home router) to the final destination (the gaming server) is shared between you and many others. That means your packets are never the only ones that are transmitted. Sometimes your packets will have to wait a split second before they can be transmitted to the next router on the path. These queuing delays depend on how "busy" it is. What the ratio is between the how big/fast/fat the network providers have built their networks, and how heavy the load of their customers is. So nobody can give accurate predictions. That would be like answering the question "how busy is a highway".

Ping (the application to do an ICMP ping), gaming pings in different games, traceroute, the concept of RTT, are all kinda similar. They all depend on these 3 factors. Some gaming pings include the response time of the server (which can vary based on the game itself, but also on load, or how many gaming servers on a physical server, etc). Some gaming pings even include the responsiveness of your PC (UT games used to do this). Ping these days is word that can have many different meanings.

 

[arredondo]

^^^ I, for one, appreciate the detailed response.

 

[imagoon]

I would also add to Gryz under "queuing delays": Pings are ICMP (they ignore TCP / UDP etc) and typically are small packets. They are also normally considered low priority and get auto queued in to the best effort QoS tier so the RTT can be meaning less.

Games like WoW also don't use "ping" they use RTT UDP packets that often include things like server response time and can include delay inside the blizzard network you wouldn't see with an ICMP ping to a world's gateway server. This is why the number varies a ton in game vs outside.

Typically it is worthless to tune for pings inside your home network. Even shaving 50% off is worthless when the ping is in the microseconds ie >1ms ping results. Your Internet provider / service provider will always be adding 1000's of % more than your pc to gateway.