Determining bandwidth...?

[Trotter]

I have an assignment in my networking class that I am having trouble understanding how to figure out. Here is what it is asking for:

Complete the following calculations: Calculate bandwidth requirements for a live event
that is streamed over the Internet based on the information below.
You are the network administrator for an Internet Service Provider (ISP). Your company
has been asked to provide bandwidth for a live event produced by one of your clients.

You have been asked to calculate the total data transfer required for the event. You have
also been asked to verify that your Internet connection can support the maximum
estimated concurrent listeners. You have a 45-megabits-per-second (Mbps) connection
to the Internet (a T3 circuit).

Event details
• Time of the event: 6:00 P.M.-8:00 P.M.
• Encoding rate: 22 kilobits per second (Kbps)
• Average length of play: 60 minutes
• Total listeners: 1,500
• Concurrent listeners: 1,200

Calculation 1: Calculate the total data transfer for the live event.

Calculation 2: Calculate the required internet connection bandwidth.

I have not come across anything regarding this, and Google is not being very helpful this morning (probably has something to due with my lack of sleep). Anyway, some direction on this would be most helpful and appreciated. Thanks.

 

[Yek]

Well calc 1 is 60 x 60 secs (total time) x 2 (for the 2 hours it's live)

x by 22kbps gives you total kbps x by no of listeners

well that's how i would interpret it anyhow

 

[Trotter]

That's what I was figuring for the the total transfer, too.

That required internet connection bandwidth would have to be 22Kbps, would it not? Or does encoding rate mean something else? Google, here I come...

 

[mikesgroovin]

Exactly, what you are going to need to do is start with a base10 calculator and a bandwidth calculator... then start throwing out variables.

What we know:

s = seconds / h = hour / 2h = 2 hours

-=Total Available Bandwidth=-
Available bandwidth/s - 45Mbps or 46,080Kbps
Available bandwidth/h - 162,000Mbph or 9,953,280,000Kbph
Available bandwidth/2h - 324,000Mbp2h or 19,906,560,000Kbp2h

-=Total Stream Bandwidth=-
Total Stream/s - 0.0215Mbps or 22Kbps
Total Stream/h - 77.4Mbph or 79,200Kbph
Total Stream/2h - 154.8Mbp2h or 158,400Kbp2h

-=Total Stream Used for 1200 people=-
Total Stream Used/s - 25.8Mbps or 26,400Kbps
Total Stream Used/h - 92,880Mbph or 95,040,000Kbph
Total Stream Used/2h - 185,760Mbp2h or 190,080,000Kbp2h

-=Total Stream Used for 1500 people=-
Total Stream Used/s - 32.25Mbps or 33,000Kbps
Total Stream Used/h - 116,100Mbph or 118,800,000Kbph
Total Stream Used/2h - 232,200Mbp2h or 237,600,000Kbp2h.

These totals are simply based off of each other so you won't find an "exact" match when converting 232,200Mb to Kb for example... but it's close enough.

The total data transfered is simply converting Kbps to KBps * 60 for a minute * 60 for an hour and then * 2 for 2 hours
We assume that 1Kb = 0.125KB
so.....


-=Total Stream Bandwidth in Mb/Kb=-
Total Stream/s - 0.0215Mbps or 22Kbps
Total Stream/h - 77.4Mbph or 79,200Kbph
Total Stream/2h - 154.8Mbp2h or 158,400Kbp2h

-=Total Stream Size in MB/KB=-
Total Stream/s - 0.00269MBps or 2.75KBps
Total Stream/h - 9.66797MBph or 9,900KBph
Total Stream/2h - 19.33594MBp2h or 19,800KBp2h

^^ That file size is PER USER

 

[Trotter]

-=Total Stream Used for 1500 people=-
Total Stream Used/s - 32.25Mbps or 33,000Kbps

So that would be the theoretically required bandwidth? for some reason I was thinking that all of the users would be using the single stream... don't ask me why. Caffeine is good for moving the body, but it doesn't help the thought processes.

-=Total Stream Size in MB/KB=-
Total Stream/2h - 19.33594MBp2h or 19,800KBp2h

And this would be the total data transfered? Or would this be times by 1500?

This is so warping my mind.

 

[SirCyber]

if I'm understanding correctly, you would times the total stream/2h- 19.3359p2h or 19,800KBp2h by 1500

:----EDIT----:
and you need some sleep bro!

 

[Trotter]

if I'm understanding correctly, you would times the total stream/2h- 19.3359p2h or 19,800KBp2h by 1500

29,700,00Kbps or 29,003.90625Mbps as the total transfered? That's a chunk.

and you need some sleep bro!

QFT! Never enough time, never enough time...

 

[SirCyber]

I could be wrong about the transfer... best to get another opinion rather than mine lol... and LOL I know the feelin! on average, between the girls mostly, my phone stays dead and I get 2-4 hours of sleep a night lol

 

[mikesgroovin]

Calculation 1: Calculate the total data transfer for the live event.
This would be:

-=Total Stream Size in MB/KB=-
Total Stream/s - 0.00269MBps or 2.75KBps
Total Stream/h - 9.66797MBph or 9,900KBph
Total Stream/2h - 19.33594MBp2h or 19,800KBp2h

This is the size of the data transfer for the live event. But, that question depends. Are they asking for the live event's transfer size ONLY? Or the live event's transfer size + the 1500 people watching it? The above is ONLY the size of the event after the 2 hours is up. The formula is simply:

1) Converting 22Kbps to 2.75KBps because 1Kbps = 0.125KBps
22*0.125=2.75

2) Taking the 2.75KBps and figuring out a 2 hour figure
(((2.75*60)*60)*2)=19,800KB

3) Simply converting 19,800KB into MB
19,800KB = 19.33594MB

So, in short... Yes, that would be correct Trotter. This is ONLY the size of the stream itself.
---------------------------------------------


Calculation 2: Calculate the required internet connection bandwidth.
This would be:

-=Total Stream Used for 1500 people=-
Total Stream Used/s - 32.25Mbps or 33,000Kbps
Total Stream Used/h - 116,100Mbph or 118,800,000Kbph
Total Stream Used/2h - 232,200Mbp2h or 237,600,000Kbp2h

Actually, if you want to get technical, it would be the total bandwidth for 1500 people + 1 extra for the stream itself... LOL
so............

Take ALL of this....
-=Total Stream Used for 1500 people=-
Total Stream Used/s - 32.25Mbps or 33,000Kbps
Total Stream Used/h - 116,100Mbph or 118,800,000Kbph
Total Stream Used/2h - 232,200Mbp2h or 237,600,000Kbp2h.

and ADD it to THIS....
-=Total Stream Bandwidth=-
Total Stream/s - 0.0215Mbps or 22Kbps
Total Stream/h - 77.4Mbph or 79,200Kbph
Total Stream/2h - 154.8Mbp2h or 158,400Kbp2h

And you get THIS for the total 1500 people and the stream itself....
-=Total Stream Bandwidth + 1500 PEOPLE WATCHING=-
Total Stream/s - 32.2715Mbps or 33,022Kbps
Total Stream/h - 116,177.4Mbph or 118,879,200Kbph
Total Stream/2h - 232,354.8Mbp2h or 237,758,400Kbp2h

---------------------------------------------------
I know that 1500 aren't going to be watching at the same time and that the total watched won't be the full 2 hours. BUT, if 1500 total people watched everything live... and you had a 45Mbps connection, you would be pushing 32.2715Mbps for the stream and to ALL of these 1500 people. So, worst case scenario, your ISP would be fine

 

[SirCyber]

Dr. IP, I just want you to know that my brain took a crap. glad you know these things cuz I'm lost, and don't worry about explaining to me, it's Trotters deal lol