HOLLYWOOD—Internet Protocol or “IP” technology entered the television production facility several years ago, and as evidenced by an increasing level of support from broadcast equipment manufacturers, is here to stay and play an increasingly greater role in transport of video and audio signals.
Reflecting this “all IP” trend, the SMPTE 2015 devoted a large portion of its Tuesday afternoon paper sessions to the subject. The first of these —“IP and Networking of the Media Facility – Part One”—consisted of three presentations aimed at determining whether IP networking is mature, versatile and reliable enough to replace SDI. The session was chaired by Al Kovalick, principal at Media Systems Consulting, who also presented one of the papers.
Al Kovalick
The first, “Prospects for Software Defined Networking and Network Function Virtualization in Media and Broadcast” was presented by John Ellerton, head of Media Futures at BT Media Broadcast. He said software-defined networking and network function virtualization (NFV) are poised and waiting to move into the TV broadcast/production arena in a big way, as they can leverage “the common architectural similarities” that exist in today’s network switches, servers and mass storage devices.
Ellerton described the creation of a laboratory model of a virtualized network at his company from off-the-shelf components and described some of the iterations of the system.
“We virtualized network functions,” said Ellerton. “We replaced specialist proprietary appliances with commodity appliances. The idea [was that] the system would change its character depending upon what we need.”
“We proved that it is possible to build very high-performance, very high-throughput networks using SDN for broadcasting applications. We were passing uncompressed video using switches that cost a few thousand dollars. We successfully provisioned virtualized functions with all of this. We think there is a future there in being able to bring all of this together in [a complete system].”
Following Ellerton’s presentation, Pradeep Kathail, chief software architect at Cisco, and Charles Meyer, Grass Valley’s production chief technology officer, took a “tag team” approach to examining whether or not the same sort of reliability achievable with today’s SDI technology could be achieved with IP. Their presentation, “Journey of 9's -- High Availability for IP Based Production Systems” described an extensive testing program to see if a “five nines” (99.99 percent) availability was possible with IP.
Kathail said that the objective was to determine if “network ‘five nines’ was similar to video ‘five nines.’”
“We wanted to make sure that every packet did get through,” said Meyer. He said the testing also encompassed ease in switching, network security and system availability. “The system had to have the dependability and quality necessary for video production,” said Kathail.
The pair described how they compared reliability attributes of conventional video switching systems with IP counterparts in terms of redundant power supplies, module swapability and the like to ensure a fair comparison.
Signal flow rate predictability (latency) was also a consideration.
“You also want deterministic behavior,” said Kathail.
The presenters described in detail their work in evaluating IP against conventional systems, and concluded that building a network using readily available IP hardware will have either the same or greater availability than an SDI network.
“We not at the bleeding edge,” said Meyer. “At this point the systems are ready.”
Chairman Kovalick concluded the session with his paper, “Design Elements for Core IP Media Infrastructures,” which provided essential information for transitioning from SDI-based operations to an IP-driven infrastructure.
“I want to frame this talk,” said Kovalick. “It’s about…how you build an IP plant for media.
Kovalick asserted that television plants SDI cores “are going to get squeezed out” by a core that’s becoming more and more virtualized. He described IP networks as consisting of three planes: a control plane, a management plane and a data/user plane.
“When you buy something, when you design something, always think about the three planes,” said Kovalick.
He explained various types of essence flow in network and a number of other attributes of migrating to IP networks.
“The really beautiful thing about IP is that you will have a flexibility that you’ve never had before.”
