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-   -   Transmission bandwidth in internet and ethernet controllers speed. (http://www.linuxquestions.org/questions/slackware-14/transmission-bandwidth-in-internet-and-ethernet-controllers-speed-4175437675/)

stf92 11-18-2012 08:24 AM

Transmission bandwidth in internet and ethernet controllers speed.
 
Hi:

In relation to the downloading of the slackware 14.0 images from internet, I have these questions:

(a) Can the ethernet controller in my machine be limiting the download speed? That is, assume the _purely_ hypothetical case in which the ISP guarantees me 10Tbits/s (some day in the distant future, perhaps). Can my ethernet card, controller or whatever its name is be so old that it cannot handle 10Tbits/s and is lowering the speed? Is there a limit for the speed an ethernet card can handle?

(b) If there is, any way to see what is the speed my ethernet card can handle, what the maximum rate is?

tux_dude 11-18-2012 09:09 AM

Short answers
a) Yes.
b) This depends on your OS. Typically, your network connection manager should list the connection speed.

Long answer:
Any data transmission is limited by the slowest component in the link from source to destination. In order to maintain the theoretical 10Tbits/s, your disk, storage controllers, memory, IO buses, CPU, NIC, ethernet cables, router/switch/modem and the lowly Slackware mirror all have to able to maintain that speed.

damgar 11-18-2012 09:17 AM

Yes. There are 1,10,100,1000 mb/s cards. In order for Ethernet to communicate most hardware will go through a handshake and negotiation process. For instance my desktop machines all have gigabit Ethernet cards and they all connect to a gigabit switch, all communication from desktop to desktop is done at gigabit speeds. However my router and my modem are both 100baseT (100 mb/s) so the link between the switch and the router as well as the link from the modem to the router are both negotiated to the capacity of the lower link so even the gigabit switch talks to the router at 100mb/s. This makes no difference because the ISP only provides me with 10mb/s which they then do their traffic shaping which limits any sustained connection to 2 mb/s. Therefor the ISP is ALWAYS the bottleneck. I can have multiple 2 mb/s connections going, but after a few hours they throttle my speeds on those ports. So for instance I had to configure Deluge to use a random port each time it opens and have to restart it occasionally if I'm doing lots of downloads for instance.

stf92 11-18-2012 11:45 PM

Quote:

Originally Posted by damgar (Post 4832002)
Yes. There are 1,10,100,1000 mb/s card. In order for Ethernet to communicate most hardware will go through a handshake and negotiation process. For instance my desktop machines all have gigabit Ethernet cards and they all connect to a gigabit switch, all communication from desktop to desktop is done at gigabit speeds. However my router and my modem are both 100baseT (100 mb/s) so the link between the switch and the router as well as the link from the modem to the router are both negotiated to the capacity of the lower link so even the gigabit switch talks to the router at 100mb/s.

Although perhaps I should learn basic concepts from wikipedia for the sake of easy communication with you, I think I understand: the path from a given desktop, from among one of yours, to your ISP is: ethernet card -> switch -> router -> modem -> elements external to your home -> ISP.

Quote:

This makes no difference because the ISP only provides me with 10mb/s which they then do their traffic shaping which limits any sustained connection to 2 mb/s. Therefor the ISP is ALWAYS the bottleneck.
You mean in your case? Because if the ethernet card is 1baseT, with the ISP providing 10mb/s, even if they shape to 2Mbit/s, then the bottle neck could very well be your ethernet card. Please correct me if I am wrong.

And now one more question: my machine has one of the NbaseT ethernet cards for N= 1,10,100 or 1000, most likely 100baseT. How do I know which one?

Kernel 2.6.21.5, Slackware 12.0

TobiSGD 11-19-2012 12:10 AM

Your motherboard's manual will tell you which network card you have.

stf92 11-19-2012 12:49 AM

Quote:

Originally Posted by TobiSGD (Post 4832352)
Your motherboard's manual will tell you which network card you have.

Ohhh! It never came to my mind! I'm reading:

o 10BaseT/100BaseTX Ethernet LAN
o LAN controller integrates Fast Ethernet MAC and PHY compliant with IEEE802.3u 100BASE-TX, 10BASE-T and ANSI X3.263 TP-PMD standards
o Compliant with ACPI 1.0 and the Network Device Class Power Management 1.0
o High Performance provided by 100Mbps clock generator and data recovery circuit for 100Mbps receiver.

What this all means in terms of my initial question is that, the bandwidth assigned me by the ISP being 1Mbit/s, and all elements in the rest of the chain as quoted by tux_dude being able to handle transfer rates well above 1Mbit/s, the bottle neck will in this case be the ISP, which agrees with damgar's words.

I think this thread answers in full the two questions that gave it rise, for which I truly thank you, guys.

TobiSGD 11-19-2012 05:39 AM

Quote:

Originally Posted by stf92 (Post 4832362)
What this all means in terms of my initial question is that, the bandwidth assigned me by the ISP being 1Mbit/s, and all elements in the rest of the chain as quoted by tux_dude being able to handle transfer rates well above 1Mbit/s, the bottle neck will in this case be the ISP, which agrees with damgar's words.

For home users the ISP will almost always be the limiting factor. The highest bandwith currently available here in Germany (sadly not at our house) is 100MBit/s. Any modern machine has at least a 100MBit/s network card, in the mid-price region and upwards it is almost always 1GBit/s. Even with wireless you will nowadays have (theoretical) bandwiths above 100MBit/s.

damgar 11-19-2012 05:45 AM

Yes, I mean in my case as far as the traffic shaping. Some ISP's don't do any traffic shaping, most have some form of traffic shaping policy though. In almost every case, regardless of traffic shaping/throttling the ISP is the bottleneck just because bandwidth is generally much higher on a LAN than a WAN.

stf92 11-19-2012 10:50 AM

Thanks again. The explanations are very clear.

kikinovak 11-19-2012 12:05 PM

I live in a remote village in the South French countryside, and Internet bandwidth is also limited to 1 Mbit/s. I don't mind though, since up until 2007 we only had 56 kbit/s dial-up.

With this bandwidth, count about an hour and a half for a 700 MB download.

As I remember, you're using Xfce, so it's enough if you download only the first and the second install CD from the set.

Cheers,

Niki


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