The grainy match, the ball almost indistinguishable from the pitch, action blocked in the middle or even delayed by a few minutes: when the Internet fails and the inefficiencies add up, the result is that you can no longer see anything or almost anything, whether it’s games or something else.
Dazn suffered numerous disruptions in the transmission of the matches of the first championship weekend, so much so that the presidents of the Serie A teams wrote a formal letter to the broadcaster asking for an account of what happened and now the responsibilities are rebounded. But the malaise is (also) infrastructural. In the sense that the problems are mainly in the Cdn, cioè Content Delivery Network (in Italian, Content Distribution Networks), a handful of hi-tech companies unknown to the general public that manage a very particular digital business behind the scenes, of capital importance for those who, like Dazn, must provide live streaming services through the Internet.
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What are the Cdn
That of the Cdn is a crucial and delicate business, because the hitches, and above all the blockages, make the difference between being able to see the game or not. So much so that, at the time, there was talk of a revolution of Serie A times to allow you to open more time windows with modulated direct to lighten the load of Dazn, eliminating or minimizing the risk of blackout. But it is all in vain if the Cdn gives up. Names like Akamai, Cloudflare, Netlify e Fastly they are almost always unknown to most people, but it is through them that the Internet passes and it is almost always their responsibility if entire pieces of the Internet become unreachable, if for example they are hit by a hacker attack or are disfigured by a bug, as has happened with sites like Steam, Airbnb, Cnn, Reddit and the New York Times.
What is a CDN for
What happens then? The explanation is actually simple, but it is not easy to understand why we have the wrong model in mind: the Internet we are used to thinking is much simpler than the real one, which is rather complicated. Usually we imagine that a data transmission, for example sending a photo on Whatsapp, takes place as a transmission between 3 points: the sender’s phone, the service manager’s server (in this case WhatsApp, i.e. Facebook), then the phone of the recipient of the message with the image. But that’s not the case.
To begin with, there are connectivity providers in the middle: in the example, one or two telephone companies, which have two very complex proprietary networks, with centers of aggregation, backbones, central and which are in turn connected to the Internet through exchange points or Internet Exchange; in Italy one of the largest is the Mix, the Milan Internet Exchange.
The Net we know begins there: in Exchange there are numerous third-party servers that connect upstream of the Internet proper to provide services such as cloud computing. Cloud services are basically real-time data storage and processing of users, which occur on servers rather than on end-user devices. And then there are the CDNs.
Distance is important
Even if Internet connections are very fast and we are used to thinking that a bit can travel around the world in a few fractions of a second, in reality the physical distance between the sender and the receiver of the message counts.
It counts so much that in the 1990s the Cdn, the companies specialized in creating local replicas of data contained in the central servers, to better distribute them and to avoid creating outages due to excess requests on the central server.
The Denial of Service risk
Overloading central servers because many are connecting at the same time is caused by the sudden success of a service or site, but often also by hackers and malicious people, which send servers haywire by loading them with millions of connection requests at the same time. When this happens the server stops responding: is the so-called Denial of Service (in Italian, Denial of Service), which is the equivalent of when a computer crashes due to work overload.
Distribute copies of the data to be downloaded in many local warehouses, i.e. the CDN servers, which then take care of delivering them to the users of a certain geographical area, it is also a great way to reduce latency, because data can be moved as needed thus optimizing the time of their download. Amazon, Microsoft, Apple, Facebook e Google they move data between their datacenters and those of their service providers trying to predict in which geographical area they are located in order to approach them, thus reducing access times.
In addition, large companies providing operating systems like Microsoft, Apple and Google upload update versions of their operating systems to the CDNs to prevent central servers from going haywire upon release.
The Cdn and the video
The uses of Cdn are many, and in fact there are many different types. Also large mobile phone service providers have created their own CDs, which are usually reserved for customers of its own network and for paid services on behalf of third parties.
However, today one more function has been added: CDNs have also become a necessary asset for the distribution of the video. From Netflix (which relies on different services and its proprietary service) to Amazon Prime (which mainly uses Amazon Web Services, the world‘s largest provider of cloud computing and CDN services), up to YouTube o Apple TV Plus, which mainly uses Akamai, live or on-demand streaming would not be possible without CDs.
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The problem is the topology of the networks
While it’s relatively easier for services like Netflix (a movie that starts 2-3 seconds later isn’t a problem), for games or other broadcasts a very complex effort is required. The Cdn that manages the service must receive the transmission and redistribute it to users with well-sized connections in the Exchange.
However, the CDNs work well above all on a planetary or continental level, but if the service is to be provided in a single country, such as Italy, there is a risk of not having a sufficiently large number of points of presence with the Exchanges.
Finally, downstream of the Exchanges, the topology of the network of the operators obviously counts a great deal they will then physically carry the data to the end users: are they present in the same Exchanges as the Cdn? Is the network capable of withstanding the load of data pushed by the CDN? Are the transmission hubs of the operators structured correctly with respect to the disposition of the users?
Networks need to be strengthened
A fine estate, many are still in holiday resorts, where connections have usually become high-speed, but unfortunately they are also low-capacity, i.e. they cannot support many connections in parallel.
During the’Winterinstead, people return to the city and in the larger ones there is a higher structural bandwidth consumption. For example, with the launch of 5G (the mobile phone service that enhances data transmission, but also consumes much more bandwidth) it is not certain that the ground networks are actually up to the load, if we add that of the streaming.
In short, the problem is infrastructural and the Cdn are the most exposed part, but the reality is that the Internet is complicated and a streaming service expects a great deal of maturity in all the segments that make it up. Something that does not exist in our country yet.
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