Wowza Community

Question on Bandwidth calculations

I’m considering setting up 2 Toshiba IP Cameras at one of my facilities and creating a web portal to allow end users to see real time what is happening.

I am trying to understand the true cost of the bandwidth needs though.

I understand how to calculate the bandwidth going from the Wowza media server to the end user (download). That is pretty basic.

What I’m having difficulty understanding is how much bandwidth will be used from the camera source to the wowza server (upload).

As arbritrary numbers: lets assume the camera I’m using requires 10 Megabytes of bandwidth per hour.

If I have one camera and 5 people viewing that same camera for an entire hour, is the bandwidth consumption 60 Megabytes (one camera to Wowza @ 10 Megabytes, 5 users downloading from Wowza @ 10 Megabytes), or is it 100 Megabytes (5 users x 10 Megabytes from Camera to Wowza; plus 5 users x 10 Megabytes from Wowza to User)?

I’m quite certain it is the former but want to be sure.

Hi

The camera will be permanently connected to Wowza as the source stream so it would be a lot easier if we calculate using the bitrate of the stream.

For example:

If the stream from the camera to Wowza is 500 Kbps (each) and you have 2 of them, the bandwidth usage will be 1 Mbps

1 Mbps x60 = (1 min) x60 = (1 hour) x24 = (1 day) total = 86.4 Gigabits per day (86.4 /8 = 10.8 Gigbytes) for the source streams.

Any views would be additional bandwidth and based on your example of 5 clients viewing for 1 hour, it would be a 500 Kbps x60 x60 1.8 Gigabits (each) 1.8 x5 = 9 Gigbits (9 /8 = 1.125Gigabytes).

Jason

Hi

I’ve edited the post above to calculate in Gigabytes for you.

Yes, it can be configured so that if no viewers are watching the stream then source is no longer active and wont be using your bandwidth until a client tries to view and at this point will get the source stream for you.

Jason

Hi

Yes that’s correct, again I tried to edit the post to add the additional info you needed but I was to slow.

Jason

Thanks Jason, that does answer my question on how the bandwidth is calculated.

I have two follow-up questions.

Are those measurements in bits, so to translate that to bytes I would divide by 8?

I read about a mediacast feature which disables the stream until a user is watching. If I implemented that, then the amount of bandwidth needed for the source streams is decreased dramatically then, right? Using the same numbers in your example above, assuming the Mediacast works as I understand it, the total bandwidth for the day would actually be 10.8 Gig?

Excellent, thank you so much.

The last question I have is around the MediaCast functionality, do I understand that correctly that the source stream will only be active when a user is connected, thereby decreasing the demand of bandwidth needs?