What to choose for a webinar system?

Question

YouTube

We are organizing a webinar service, and at the moment we are faced with the choice of a solution for WebRTC video.
There are three options:
1. Free solution on Kurento media server. The service is currently running on it. Cons: no iOS support, and for current users, iPhone support is very important.
Costs :
- server: 4k (rubles)
2. Media server Web Call Server 5 (Flashphoner). There is everything you need, screen sharing, iOS, video recording, load balancer, etc.
- 3 server licenses - 12k
- rent of 3 servers - 12k.
Total to provide 1000 concurrent online connections: 24k./month including servers, licenses, etc.
3. Use cloud service for WebRTC video - OpenTok. Expenses: for an hour webinar for 100 people - 360 rubles. But there are no costs for servers, maintenance, etc. There can be 2 webinars per day. And per month only for our expenses - this is 18,000 / month.
What would you advise in our situation?

Answer 1

I will describe my own way of building video broadcasts:
For video broadcasts I use FreeSwitch, it has a mod_conference module that allows you to create a video conference. (According to the idea, all the speakers of the conference, which are much less than the number of participants added to the conference)
And you can broadcast the conference to many viewers using mod_rtmp The mod_rtmp
mod can broadcast the video stream of the conference to nginx with the nginx-rtmp-module, which in turn can relay the stream between servers or give in hls and mpeg-dash to viewers.
Thus, you can watch hls stream from iPhones.
Here is a general instruction on how to make such a video chat
I also asked a question on this topicHow to implement one-to-many video streaming with minimal delay? and there in the answer they recommend to get acquainted with an interesting solution for stream delivery via websockets.