Can One File Really Bring a T1 Line to Its Knees?

[FredGarvin]

Howdy all.

I have a somewhat tenuous relation with our IT department. Basically because they think they are the only ones who know what happens inside a computer. It's an annoyance usually, but every once in a while, something comes up that makes me think they are complete buffoons/idiots. The most recent issue came up the other day when I was downloading a video file.

I had the need to download a file that was 160 MB. We have a T1 line that is used for all of our communications/data transfer between plants as well as internet access. So I am in the process of DL'ing this file when the IT nazi's come calling saying that my one file has brought the network to its knees. I looked at them blankly and mentioned that it was just one file. They countered with the fact that it was 160 MB.

Now, I am no expert by any stretch of the imagination when it comes to internet protocols ,networking and such. However, my BS meter was getting pegged now. I understand that everyone has a certain byte per second limit in their communications, but I think this is unrelated to their complaint.

Does it make sense that one file can bring a T1 line "to its knees?" In my simplistic view it should be a function of how many different things are being done at anyone time, not the size of the individual files being transferred. To me it seems like we should have been very close to the transfer limit and my file put it over the top. Is this how internet communications work when it comes to file transfers?

Personally I think they are full of BS in blaming my one file download. However, I am open to learning what is really going on. So please, set me straight here!

Thanks.

 

[Ronnin]

It really depends on how fast it took to download the file. The file size doesn't matter it's Mbps. A lot of routers give priority to different types of traffic and most likely that is what happened with this download. Your IT guys probably noticed the spike in network load and gave you the call. Truth be known they probably download stuff this size all the time but since your not in the inner circle you got the call.

 

[MATLABdude]

I would hope that your IT department would have implemented some sort of QoS (Quality of Service) rules to keep you from hogging all the bandwidth, but the ping (and thus, perceived 'responsiveness' of the internet) can go down when, for instance, you're torrenting at 750 kbps (up and down, combined) on the department's dime. Not that I've ever done that, before.

However, you were probably just interfering with their downloads / gaming. J/K(?)

Edit: Ah, the joys of academic internet access, and having an OC-whatever connection straight to the net!

 

[FredGarvin]

I would hope that your IT department would have implemented some sort of QoS (Quality of Service) rules to keep you from hogging all the bandwidth, but the ping (and thus, perceived 'responsiveness' of the internet) can go down when, for instance, you're torrenting at 750 kbps (up and down, combined) on the department's dime. Not that I've ever done that, before.

That's pretty much what I am getting at. I would think that the network would have, at worst, an even distribution allotment of how many of the kbs limit. If you have 10 things being sent over the network at one time, then each transfer rate would be the limit/10. That's pretty much how my connection at home works. I just assumed that a business would have a better set up.

 

[ranger]

Your file size of 160MB could potentially slow things down if you're downloading at a rate of about 1 Mbps. At that rate it would take about 20 mins to fetch the file. So if you were doing 1 Mbps consistently with short bursts of 1.5 Mbps, you could cause some problems. Now seeing that how this is a business setting, they must have QoS rules in action because its a shared connection among employees. My guess is that the IT guys were just picking on you. Maybe they saw the vid file as a waste of bandwidth.

What you could do is try it again with a video file of about the same size and note your average download speed and if they call you up again.

 

[Evo]

It depends on the rules they have set for allocation of bandwidth. They might not have expected anyone to download such a huge file and hadn't set up rules to throttle downloads back. If voice is carried on the same T1, rules should always set a protected minimum for voice and give voice priority over data (not allowing data to burst to the point where it takes away the voice bandwidth). Your download could have choked out other data users.

 

[harborsparrow]

Video packets may get higher priority than regular internet packets. I doubt the 160Gb is going to break the bank, but I can somewhat sympathize with IT. In general, most workplaces expect their employees to avoid using the work network for video UNLESS IT IS WORK RELATED (and even then, if there's a non-video alternative, use it instead). Otherwise, if all employees start, say, surfing news videos at lunchtime, the network truly would grind to a halt.

So unless that video was essential to your job, I think you'll just have to let them have their lecture this time.

 

[Pengwuino]

It all should come to QoS as people have noted. If your IT department has an idea what they're doing, they should have it setup so that one person can't cripple the network. Downloading a 160MB or 16MB file will result in the same download speed. It's hard to imagine no one in the company has had to download a remotely large file like that.

On a simple home network, a computer will take as much bandwidth as it can even on a single file. If on another computer, a download begins, the router will split up the bandwidth for the most part (I don't know the technicals). If you use QoS, it caps connections based on how much bandwidth you want to give them. If your IT department didn't want to give you that bandwidth, they should do the quite simple task of implementing QoS. Hell I don't know much about networking but even I could implement it.