EC2 Live streaming open questions

[m_seeger]

Hi everyone,

I'm evaluating the use of a Wowza2 Origin/Edge setup via the Amazon EC2 Service.
I spent a considerable amount of reading time in this forum, but there's still some loose ends I need to tie up (some of the following questions may have already been answered here, but I really did look hard and still I'm not enlightened).

The scenario is live streaming (640x480) of individual events (2hrs-10hrs) to a rather smallish (200 max) user group - although I'd like to get a feeling for possible future scenarios, so I'm also interested in a 600 users setup.

Here's what information I compiled so far:

(1) an on-site encoding software/hardware pushes the stream (H.262/AAC) to the origin server
(2) the origin server distributes the stream (RTMP) to several edges
(3) the (flash) clients request an edge IP (load-balanced) from the origin server
(4) the flash client streams the video signal from the assigned edge server

- is this the correct setup for live streaming?
- is 500kbps acceptable for a 640x480 stationary recording of a scene with not too much movement?
- What do I need for encoding/pushing to origin? At the moment, it seems I'll be provided with an analogue PAL signal.
Can you recommend any affordable hardware/software encoders (flash media encoder is out of the picture due to legal issues).


- how many edges do I need for x users? I did some calculations, perhaps you are detecting major errors:

edge bandwidth: 250Mbps (70% of 350 Mbps for XL server, considering overhead/safety margin)
stream size: 500 kbps
users: 600
Mbps/stream: 500 kbps / 1000 = 0.5 Mbps
edges needed: round_up( 0.5 * 600 / 250 ) = 2

- for up to 500 users I only need a single XL server, no origin/edge setup, is that correct?

- I did some cost estimates and discovered that with EC2, server rent and incoming bandwidth cost are virtually irrelevant compared to the outgoing bandwidth. Can you confirm that?

Do I really have to expect way below $300 in cost when I'm streaming 500kbps 10 hours straight to an average of 600 users?
Somehow I fear there's a flaw in my calculations, so please tell me if I'm erring in like a magnitude of ten, so I won't get into trouble ...

Here's my calculations:

Incoming = (site -> Origin) + (origin -> edges) = 1 + num_edges
Outgoing = (origin -> edges) + (edges -> users) = num_edges + num_users

I am assuming an all-time peak, which will give me a (non-realistic) upper bound:
(500kbps, 600 users)
stream size/h = 0.5 * 60 * 60 / 8 / 1024 = 0.22 GB/h (per stream)
out_cost/h = 602 * 0.22GB * 0.17ct ~ $23


Thank you in advance for your time