Specs for a audio steaming server for max 20k users

[Diakatarnis]

Hi,

I was wondering if anyone had some thoughts on streaming audio to users through a local network.

I'm looking at a server to do the job, but wonder if anyone knows what the cpu usage would be like serving 20k people (max)

the stream will be going out at 128kbs and you can get roughly 7000ish people on a single gigabit connection so ill need to use more than one network card in the server (do fiber cards work any faster?) and do some magic with vlanning on the switches / access points etc.

Does anyone have any suggestions about specs? at the moment im probably going a bit overkill with a dual hex core server 32gb ram, will i need to go this mad?

Also ive not really had a look at AMD's Opteron offerings but a dual 8 core opteron is about the same price as a dual hex core xeon, so which (if either) offers better performance?

Any thoughts would be appreaciated

 

[Diakatarnis]

tbh i agree, but the customer doesnt really have the budget for multiple smaller servers, ideally i would like say 1 server per 5000 people.

I'm assuming (as i havent spoken to the software people yet) that they will be using shoutcast / icecast on a server 2008 box.

I would assume Linux would better handle the load?

Having said all this it might be a better idea to get them to purchase 4 second hand dual quad poweredge servers jam in some extra ram, and that would spread the load better.

 

[Diakatarnis]

Well, you may have no choice, it might just not scale up like that - I also highly doubt you'll get anywhere near 7000 users in a gigabit connection in reality, particularly with that kind of traffic. You could go to 10GigE but that's rarely worth the price premium.

What you should be doing if it's internal is multicast...

Well a 1gb connection is about 7k users @ 128kbps but i've now gone with 4 servers splitting it down to 1250 users per server which should be a lot better.

My worry is that using the same principle a 54mb/s access point in "theory" should handle about 400 users streaming. I'm not going for minimum mind i was going to put in 30 units.

 

[Diakatarnis]

20k users, at once, on a LAN? I can't think of an organisation that matches this sort of profile.. Can you elaborate (just for my curiosity?).

Its a stadium, and its max is 20k users full, tbh the client has requested 5k users as their max, but you know how people change their minds, so i want to have a backup plan.

 

[Diakatarnis]

1 AP might handle 400 users worth of bandwidth but it's going to need to be some serious kit to handle 400 separate wireless connections regardless of what bandwidth they use.

At the moment im looking at RB411AR as they supposedly (according to the reseller i spoke to......) can support 200 users each and 500 with the 600mhz model, im contacting the manufacturer as I want it from the horses mouth so to speak.

 

[Diakatarnis]

Better off going down the Icecast route with multiple relay servers (what I’ve done for similar projects); just make sure your master is reliable (doesn't need to 'uber' compared to the relays). And if using Icecast, then use the -khhttp://www.xiphicecast.webspace.virginmedia.com/ modified version, has a load more new features especially the ability to redirect a listener when the server 'max-listeners' has been reached.

What i was thinking was having 5 servers, 1 relay / http server and 4 streaming servers each serving 1/4 of the user base (using 5k as the max 1250 each) servers will be dual quad core with 16gb ram and 4x 15krpm sas discs (not that they will be using them for anything)

Not really sure whether to go the Standard server route or Linux either tbh, descisions descisions.

 

[Diakatarnis]

Thanks booney,

Another thoguht has come into the mix, delay.... i have to get a feed from their sound desk, encode it and then send it to a icecast server to then be distributed to the users...... now they want as small a delay as possible, 1 - 2 secs at most and from previous streaming fun with radio stations etc this is very unlikely....

 

[Diakatarnis]

I think it's worth saying - you should speak to a specialist in the area, even the network side of this isn't a challenge I'd fancy, it's too specialized by half for my liking. You need to speak to somebody who does this for a living. If I was asked to provide this as part of a project that's what I'd do anyway.

Indeed, im beginning to think the same, what started as "can you stream audio to peopls phones" has slowly gone to "can you stream announcers in real time to people phones with no delay and oh can you ti into our soundesk etc"

Its one of those jobs where you get a tiny bit of the picture and thing "ok no problem" then the larger picture slowly becomes visable and the costs start increasing beyond the initiual estimate....