How SDN And Film Digitisation Power The Berlin Film Festival

The Berlin Film Festival has 2,500 screenings over 11 days. Software Defined Networks and digital film make it happen

The Berlin International Film Festival has been a fixture in the calendar for cinephiles since 1951 and each February takes over large swathes of the German capital.

This year saw more than 2,500 showings take place in 51 theatres in 17 venues as movies from around the world competed for the coveted Golden Bear.

The organisers of the event experience many of the same technology challenges as their counterparts in the sports industry. Months of relative quiet are followed by a short, intense burst of activity.

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It’s why Colt regards the Berlinale as the perfect showcase for its software defined network (SDN) technology because the company can offer increased capacity using its global network whenever it’s needed.

The UK-based company has been in Berlin since 1997 and has a 1,700km fibre network in the city, connecting 1,200 properties.

“[Berlinale] represents where we’re talking Colt as a company,” said Carl Grivner, Colt CEO.

Colt has been a partner of the festival since 2009 and will be for the next three years, helping organisers download films from around the world to the company’s data centre in the city.

Previously films would be sent across on hard disks and then sent manually around the city using messengers. Not only was this inefficient, it had its own dangers, especially in the winter.

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“A lot of messengers are hired by Berlinale to bring these movies from the film office in Potsdamerplatz to the theatres,” explained Colt. “Besides the cold, there is snow, there are challenges and it brought uncertainty.

“From 2011 onwards we started to connect venues around Potsdamerplatz and we provided 1Gbps LAN link to these venues from the film office. [This] meant they could distribute films via Colt fibre network. In 2013, we connected more cinemas and venues so we were able to deliver services to most competition venues.

“Most of the year, the fibre isn’t used, but from the Autumn onwards when the pre-screening starts, it is.”


The digitisation of the film industry started in 2005, allowing films to be distBerlin Film Festival 2017-1ributed digitally rather than on 35mm film. These movies come in the form of digital cinema packages (DCP) that can be up to 200GB in size.

Berlinale has dedicated equipment within the Colt data centre, including special servers and DVD re-writers. During the festival, Colt dynamically increases network capacity to help transfer around 1PB of data.

The sheer number of films and screenings make it a considerably more difficult task to manage than a traditional multiplex, most of which show only a handful of films several times each week.

Ironically, because of the equipment used, the festival’s technology office is the only permanent facility organisers maintain. Here, volunteers check for format and language before the file is stored locally at the venue.

Streaming and security

Colt’s network is encrypted to protect against piracy but most of the DCPs are also protected with keys that only allows them to play at a certain time at a certain venue.

“We have more than 2,500 screenings so we manage a lot of keys,” explained Berlinale technical director Ove Sander. “So we developed some tools and try and get a master key and generate our own.”Berlin Film Festival 2017 (4)

Encryption posed other challenges too. Until recently, the festival had no way of telling if the keys would work until the day of the screening.

Sander said the digitisation of old films was a “painful process” because of the compute power needed and although Berlinale maintains a 35mm projector this is solely for archive footage. Instead, films are shown on more up to date equipment partly funded by distributors who had a vested interest in updating the process.

But despite the advances made in network technology and the digitisation of the industry, Sander doesn’t think real time streaming is on the horizon because although bandwidth might be available in Berlin, it’s less likely to be available at your local cinema.

After 11 days of competition, the 2017 Golden Bear was won by Hungarian film Testről és lélekről, which translates as On Body and Soul.

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