Blog Posts

IBC2014: Notes from the show floor – Yes, but why Ethernet?

 Yes, but why Ethernet

File-based infrastructures – old hat. Software-defined networks – this year’s must-have. IP connectivity – everyone is doing it.

Underpinning it all is a 40-year-old connectivity standard: Ethernet. In the broadcast business we are accustomed to high performance, albeit industry-specific, interconnections. You would be tempted to think we are moving in the wrong direction by migrating to Ethernet.

What has actually happened is that Ethernet has moved to broadcast standards of speed and predictability – even for live production workflows. And the economics make it impossible to argue a case against.

The IT industry is focused on building big data centres. They hold this whole cloud thing together. These data centres need switches for hundreds of 10 gigabit Ethernet signals. Commoditised 40 gigabit Ethernet will be with us soon, and 100 gigabit Ethernet the week after that.

The finance industry is looking for extremely fast connectivity. Providers of data paths between New York and Chicago compete on the precise length of the cable because of the difference in microseconds it makes. Hold a financial transaction up, even by a fraction of a millisecond, and you could cost someone a lot of money. Extremely low and predictable latency is also readily available.

Capacity                   

What does that have to do with broadcast and media? Now that Ethernet has sufficient bandwidth, it is looking very attractive to move realtime content around. A 10 gigabit Ethernet cable can carry six HD signals in each direction.

So if you are building a facility, that is a 12 to one reduction in cables. Saves money, saves time, keeps the place tidy.

We are also looking at virtualisation – putting much of our signal processing on standard IT platforms like high performance blade servers. That means there are plenty of signals in IP form we want to move around. And these blade servers have 10 gigabit Ethernet interfaces built onto each blade.

We are growing to love blade servers because the IT industry pours investment into making them faster, cleverer and cheaper. And perhaps we should love Ethernet because the IT industry pours investment into making switches faster, cleverer and cheaper. It means we can concentrate our investment on the clever software that does what we need.

Standards

But we know where we are with SDI. I wondered if there was an equivalent standards process for IP signals. So I asked John Mailhot of Imagine Communications. He made an interesting point.

“Today, voice over IP feels like a phone,” he said, “and that is the goal. We want to be in a place where the operator forgets there is IP technology underneath the button, or even that there is a mix of IP and baseband. If you are an operator, you just want to reach out and punch a button to put a feed on a monitor.”

SMPTE 2022 seems to be the standard that makes this possible. It deals with all the tricky stuff like forward error correction and jitter. 2022-7 provides for redundant paths, and 2022-6 allows for fast translation between IP and baseband.

“When you install devices that natively speak IP then you have the ability to tilt the economics very quickly,” Mailhot explained. “But you have to respect the investment our customers have made in capital equipment. So we have to allow for hybrid infrastructures to manage the transition.”

by Dick Hobbs, consultant and writer on television and communications technology