Even with a large amount of bandwidth available (25mbit+), why do online games lag?

[Saint Nick]

Room mate streams/torrents once in a while and makes the online games lag. Even with a large amount of bandwidth, why does this still happen?

 

[Crusty]

You are either saturating your upload speeds or your router can't handle the torrent traffic. Torrents are hell on consumer devices, especially if the user has gone in and 'tweaked' the torrent client to use many more connections.

If you're the one paying the bill tell him to cut the torrents out or cut his access off, you do not want to be liable for any legal trouble he might get into.

 

[Saint Nick]

You are either saturating your upload speeds or your router can't handle the torrent traffic. Torrents are hell on consumer devices, especially if the user has gone in and 'tweaked' the torrent client to use many more connections.

If you're the one paying the bill tell him to cut the torrents out or cut his access off, you do not want to be liable for any legal trouble he might get into.

So a good, quick fix would be to at least tell him to limit the amount of connections and really put a heavy cap on his upload speed, as well? I'm not talking a BP-quality cap here, either...

 

[Gillbot]

Throughput doesn't always mean faster, latency can make a "fast" connection seem slow.

 

[SunnyD]

Throughput doesn't always mean faster, latency can make a "fast" connection seem slow.

This.

Latency, in lay terms, is the time it takes for the "message" to make it from your computer back to the server, and/or possibly round trip back again.

If you have something that requires acknowledgement that a packet of data has been received before the next one can be sent, then under high latency periods your throughput goes down.

Another issue is packet loss. Some modes of communications that require a constant stream of packets to come across may have to re-request a given packet if it doesn't arrive (in order or at all - yes, this happens). This causes communications to stall while the packet request is made and retransmitted again.

Your 25Mbit/sec is best-possibly scenario under optimal conditions.

 

[imagoon]

Torrent issues (and the rest of the network at the same time) are also amplified by the asymmetrical speeds of the connection. 25mb/s is prob your download speed, while the upload speed is some tiny fraction of that. Sometimes even in a pure download state the TCP ACK's going out can saturate the upload channel slowing the download channel. This is the primary reason of late why ISP's increased upload speeds. A 25mb/s down 256k up channel would never reach 25mb/s. The slower upload channel will tend to have a higher latency because the slower bitrate takes more time to send packets from one end to the other.

Add that in with uncapped / unlimited torrents raining down on the connection with typical consumer gear, you will end up with lag spikes.

 

[Pulsar]

What people are saying, in more or less complicated ways, are that there are different measures of what a good connection is.

There is throughput - this is the total 'bandwidth' of your line.

Then there is latency,jitter, and a couple other measures.

Latency is how long it takes your 'ping' to get to the target and back.

Jitter is (very basic), the deviation in your pings. There are different ways to measure jitter since there isn't a standard definition. But look at it like this. If your first ping is 20ms, and your second ping is 120, your average may be 70 ms, but your experience is going to suck as things will stutter (voip is dependent on low jitter).

While your roomate isn't using all the bandwidth, it's a gaurantee he's blowing your jitter to hell with the hundreds of ports and connections that torrenting uses.

Tell him to get his own connection if he wants to meet the FBI some day. You're probably not real interested in making new friends that way.