[Tech] Download Caps for Certain Users on a LAN?
- Thread starter Nanor
- Start date
Ki!ler-Mk1
Active Member
Well, as far as I understand it, it's not about how much data gets transferred but when and how quickly. Your online game (whatever it is, lets assume a FPS) probably makes a lot of connections to the server for positioning updates etc but with nominal information (x,y,z, stance, action). While not being a lot of data, quick response is fairly essential. If someone is using large amounts of data (eg Skype) your packets of data will not be sent/received quite as often thereby creating what we lovingly refer to as "lag".
I think that makes sense in a simplified way
Thanks that mostly makes sense, though i was under the impression that a persons max transfer(say 100kbps) means you can transfer 100kbps at the same speed you could send 10kbps, as speed is irrelevent and the only factor is how much you can send at once?
There are a few concepts one needs to know in networking to understand how it all works.
Networks are made up of bits of hardware linked by wires.
Each wire has a bandwidth, which is what gives you your measure of how much information can be transferred "at once" (e.g. 100Kb/s).
Each wire is a certain length, type and quality and these factors all judge the latency of the wire, which is the time it takes to get a piece of data from one end of the wire to the other (e.g. 100ms).
Each bit of hardware does a different job but ultimately there are only two decisions to be made: whether to allow a piece of data to pass onwards, and where to send it. Firewalls just decide the first. Switches just decide the second. Routers do the second but in a more advanced way. Home routers often do both (as they contain a firewall).
When data is sent, the sending device usually listens for an acknowledgement that its data has been received (e.g. TCP). Sometimes, data is just sent with no need for acknowledgement (e.g. UDP).
Each bit of hardware is capable of handling a certain quantity of data at once. The quantity of data it can handle is measured by the speed at which it processes how to handle the data and the size of its buffer. In here we get what we call packet loss, which is caused by the queue being processed too slowly. Either the buffer is overflowed or data takes too long to make it through the queue. (For TCP connections, the data is just sent again. For UDP connections, that data is then lost.)
Lag is a combination of latency and packet loss. Thus slower, longer wires and slower, cheaper hardware creates lots of latency and may suffer packet loss.
Networks are made up of bits of hardware linked by wires.
Each wire has a bandwidth, which is what gives you your measure of how much information can be transferred "at once" (e.g. 100Kb/s).
Each wire is a certain length, type and quality and these factors all judge the latency of the wire, which is the time it takes to get a piece of data from one end of the wire to the other (e.g. 100ms).
Each bit of hardware does a different job but ultimately there are only two decisions to be made: whether to allow a piece of data to pass onwards, and where to send it. Firewalls just decide the first. Switches just decide the second. Routers do the second but in a more advanced way. Home routers often do both (as they contain a firewall).
When data is sent, the sending device usually listens for an acknowledgement that its data has been received (e.g. TCP). Sometimes, data is just sent with no need for acknowledgement (e.g. UDP).
Each bit of hardware is capable of handling a certain quantity of data at once. The quantity of data it can handle is measured by the speed at which it processes how to handle the data and the size of its buffer. In here we get what we call packet loss, which is caused by the queue being processed too slowly. Either the buffer is overflowed or data takes too long to make it through the queue. (For TCP connections, the data is just sent again. For UDP connections, that data is then lost.)
Lag is a combination of latency and packet loss. Thus slower, longer wires and slower, cheaper hardware creates lots of latency and may suffer packet loss.
X download does not equate to Y upload - ADSL is asynchronous i.e. the upload is usually a fraction of the download. Say you're downloading at 1mbit, you're upload ack packets, DNS requests and resent packets (to cope with any loss) could easily account for a signifant chunk of your upload speed. The more network loss and the smaller the TCP packets then the worse things become.
Basically each TCP each connection is a two way affair with packets sent and then reply packets sent back to say the original packets were received.
Add this concept to that of network latency (or round trip times) as well as queue sizes for your network devices and suddenly a simple download start affecting other network streams as everything backlogs behind a queue of other traffic.
Even though most games are predominantly UDP based (no reply (ACK) or resent packets they are still affected by other network trafffic. Most home connections end up being upload limited which causes high latency and network lag.
i was going to say what haven said, but using the analogy of a drain pipe and a garden hose, your download is like a drain pipe, but it also feeds a garden hose which is your upload, the fuller the drain pipe the more water the hose has to get rid of and eventually the hose chokes and cannot put out enough water to stop the drain backing up and then you get lag...
could word it better, but you get the principal
could word it better, but you get the principal
Ki!ler-Mk1
Active Member
I feel quite thick right now.
I can understand some of whats being said. Though i still have trouble understanding why i get lag when only using 20% of my DL/UL capacity. I shall have to reread whats here a few times in the morning.
I can understand some of whats being said. Though i still have trouble understanding why i get lag when only using 20% of my DL/UL capacity. I shall have to reread whats here a few times in the morning.
You're using 20% of your download but that does not necessarily equate to only 20% of your upload - the point is that your upload speed also dictates your maximum download and the overall speed of your network - if you are upload limited then it will affect your overall download speed and network performance.
Also just to confuse you even more
you cannot reliably perform QoS on download speed, you can only adjust your uploads and use that to affect your overall download
Ki!ler-Mk1
Active Member
Aaaaaaaaaaaaah, i actually meant that i got this information while using software to monitor the UL/DL rate in real time. Its really difficult to understand why programs cannot share a connection lol.
Ki!ler-Mk1
Active Member
Hey, im sure ill get whats wrote here eventually