CDN in the backpack. How we made portable CDN

    At the CSTB television show, we needed to talk about CDN and show the essence of our business clearly. To do this, we have put together a working model for broadcasting videos over the Internet. Of course, we did not take into account in this model the algorithm that makes up the know-how of our service, but the basic elements of the work of CDN are shown. It began, as usual, with the project:

    We will talk about what is on this diagram a bit later. First, about the event. CSTB is considered the largest television and telecommunications exhibition in Eastern Europe. For many television people and everyone associated with television, this is a landmark event. If you rent a booth here, this is to some extent an image step. The exhibition is professional, there are no random people, and the presence among the exhibitors is a way to say that your business is going well.

    Well, of course, there is a chance to meet a potential partner, so many attract visitors to their stand with non-standard moves. For example, the TV1000 Action channel hung on the walls hand-drawn posters in the spirit of a provincial cinema:

    And at the stand of the First TVCh television company, a girl first played the violin, then pipers in skirts acted and to complete all of the above was a striptease (we did not photograph it):

    We thought for a long time how to introduce our company. At first they wanted to broadcast a lot of windows with different videos on the screen, then play some kind of game with visitors. There was also an idea to launch a robot at the exhibition, which would walk between the aisles and call for a stand. However, all these are traditional moves for exhibitions, and I did not want to use standard methods. As a result, we decided to assemble a miniature CDN model at the stand. The idea came at the very last moment, and therefore the scheme was drawn in a couple of minutes by hand.

    We placed two televisions on the stand. A presentation about the company was spinning on one, and on the second we put out an Internet broadcast using special equipment and two cameras located here. One camera broadcast what was happening in front of the stand. The second was aimed at the toy railway, which we bought in the Children's World and assembled at the stand. In order not to leave the “iron” unattended, we dismantled our CDN every evening and put it in a backpack, and mounted it again every morning. The entire installation process took no more than 20 minutes - the model turned out to be compact.

    Of the two cameras, one was an IP camera (1080P Color IP Camera ELP-IP618A). She issued a video stream in RTSP format, which is already suitable for display in an Internet browser. But we passed this stream through CDNbox - a device that converts it to RTMP format. It benefits in image quality and stability compared to RTSP.

    The second camera we shot in HD-format. We connected it to the Avermedia Avercaster HD Duet transcoder, which converted the signal from the HD camcorder to RTMP. It was an ordinary camera with an HDMI connector (Sony HDR-CX220E). So we showed that you can even use an amateur camera to stream video to the Internet:

    Next, the RTMP video was transferred to a laptop (Dell Inspiron 11), which played the role of a server:

    Wowza was installed on the laptop, a software that streams video to the Internet. Wowza sent a video stream to a page with a built-in player - we wrote it in HTML in 20 minutes. This page simulated a website on the Internet where video broadcasting is being conducted. It was displayed in the browser, which was installed on the TV by default. All components of the circuit were connected by a router - an ordinary TP-Link.

    Of course, it was impossible to demonstrate all the features of CDN using such a model. Our goal was simply to show that the broadcast of the World Cup or the Olympics is not necessarily associated with a TV, an armchair and beer. This is all broadcasting, but there is also broadcasting over the Internet.

    During broadcasting, the signal travels through the air most of its way from the camera to the viewer. The camera transmits it to the signal processing center, then it sends the transmitting antenna through the repeaters to the receiving antenna, and only then the image passes through the wires to the television receiver. In the case of Internet broadcasting, the image in digitized form immediately enters the network and then is transmitted by wire in Internet formats.

    For example, to ensure broadcasting of 300 thousand Internet connections, you need a network of 100 servers. At the same time, we do not just install “hardware”, but “balance” it so that with each specific user the node that works best for it works the most. If the channel is blocked somewhere, the distribution is from another node. Our competence is that residents of different regions can enjoy guaranteed uninterrupted viewing of the broadcast.

    A special software package called a “load balancer” solves an equation with three variables: channels, nodes load, user location, and gives an optimal solution for each connection to the broadcast. The Balancer is located on a separate “server farm” in our main data center in Moscow. This is a serious technology, it is protected by a patent and is our know-how. It is a pity that in the conditions of the exhibition it was not possible to demonstrate its work.

    If we wanted to bring our exhibition model as close as possible to reality, then several laptops would have to be placed throughout the exhibition, and 25 TVs would be needed for clarity. Probably, we would also need a separate laptop with a “balancer”, which would have been very difficult to show . Therefore, there was a second TV on the stand, where we played a presentation with a detailed story about the technology.

    By the way, the crisis did not become an obstacle for the exhibition: they still want to talk about themselves and make plans for the development of the company. Perhaps, there were almost as many exhibitors as last year. Only there were not so many visitors. The day after the opening, when the peak of visits occurs, they seemed to be two times less. But they ran twice as fast as usual, and no one had a pessimistic mood.

    The trends of video-related industries remained unchanged. The first and most important trend: TV channels continue to go to the Internet, OTT services and smart TV. The second trend: companies producing specialized content are thriving, despite the crisis. We saw people making videos about hunting, fishing, kitesurfing, windsurfing. If the crisis hit anyone, then only those who did not have a clear business model.

    Also popular now: