TV on Wheels Book Excerpt: Remote Production, Part 2 — Networking
Ten years ago, Jim Boston and George Hoover published TV on Wheels, a book that celebrated and explained the history, operations, and logistics of remote-production-vehicle operations. The newest edition, published last fall, extends its editorial scope with expanded coverage of engineering topics: going digital, networking, and file management, as well as audio consoles, replay devices, cameras, lenses, and more. Here’s an excerpt from the chapter on networking.
While the final top level deliverable out of a truck today is still, in most cases, a stream or a group of audio and video streams, increasingly, the workflow to do that is orchestrated by IT. Information technology is the blanket term that covers how multiple computer-network–aware nodes communicate and share information with each other. The truck industry tends to refer to this as I/P networking, most likely a cross between IT and production. Historically, this I/P networking, which we will refer to as simply networking from here out, was numerical data that represented everything from characters, pieces of a picture, addresses to number values for their own sake. The fact that the vast majority of computers from the 1940s on dealt in number values meant that they were digital. The “digital revolution” started more than three generations ago.
Networking on the Road
“Modern television equipment employs networking technology to both provide control and process audio and video signals. As an example, today’s production switchers use LAN architecture to connect the switcher’s control panel and auxiliary panels to the electronics frame. Almost all equipment today is built this way: a control surface connected via a LAN to a processing frame. Audio consoles work this way as well. Routing-switcher control panels connect to the physical matrices through a controller via a LAN. Graphics generators and video servers are really nothing more than specialized computers with video- or graphics-processor cards; these computers can be networked together, just like business systems. And, of course, all trucks need to support traditional IT functionality of Web access, e-mail, and printing. Other networks can be used to transport multiple audio channels over single-network-cable point to point and point to multi-point.
List of Common Networks at a Venue
- Public Internet — for general Web surfing by the crew and e-mail
- The public Internet behind a firewall, spam filter, antivirus, etc. — used to get to the Web for files going to servers, graphics machines, troubleshooting, etc.
- Production switcher — panel to mainframe, aux busses
- Cameras — CCU to RCPs and master setup panels
- Router panels
- Audio console
- One or more replay networks
- Terminal-equipment control panels for control of frame syncs, color correctors, and other modular gear
- Tallies and under-monitor displays
- One or more audio networks
- Enhanced graphics (PVI, SportVision, SportsMEDIA, scoreboard interfaces, bug boxes)
- VoIP phones
The danger on a remote site is intermingling the various networks together. The consequences of connecting the public network to the switcher LAN, creating a scenario where e-mail checking and Web surfing are occurring on the same LAN, can be disastrous. The switcher becomes infected by a virus, or the switch execution times are slowed by network traffic.
In large events, multiple trucks can be connected together, including their LANs, creating collisions if IP addressing is not planned out properly, such as if two devices have the same IP address.
The technical portion of networking on a truck generally needs to be known by a couple of people, the EIC and E2 (engineering assistant); the practical implications of networking, such as what to plug your laptop into, need to be understood by everyone on-site.
In most organizations, the IT department is in charge of all things LAN, TCP/IP networking, and usually all applications in use, especially from a strategic enterprise-wide view. Even many local broadcasters have adopted this approach. While broadcasters will often refer to separate business and operational networks, today, in many facilities, if it is IT related, from switching to air or working with Excel spreadsheets, it is under the watchful supervision of IT. Even though the first computer and LAN use was in engineering and operations, this IT focus reflects broadcasting’s shrinking share of revenues, as more and more cable or satellite outlets compete for end viewers.
The name of the game today for broadcasters is to do more with less. Most decided long ago that meant one IT department, and the loss of e-mail or the station’s traffic system, the two largest IT tasks, seems to trump operational concerns, short of the station being off the air.
Remote television production grew up differently. While computers have been found on trucks for 25 years, they were usually standalone boxes. The pressure to automate many processes using computers linked together was never as pressing out in the field. Any system that had the early markings of a computer LAN was often an island unto itself, and often even those involved with them didn’t think they were “networking.”
While e-mail started showing up in the field when trucks started seeing dial-up connectivity, none had e-mail servers on board, and e-mail clients simply “dialed” into a server back home. About 10 years ago, equipment started to reach out, instead of being comprised only of pieces specific to its own system. It allowed outside clients, usually run on generic PCs, to set up and operate a system, whether audio/video routers and intercoms, video switchers, cameras, or processing equipment along the audio and video sequences.
So, in the truck world, it is the engineering effort that still far outweighs the office side. Even with all the advanced technology, the constant dis-assembly and re-assembly, the exposure to the elements, the sometimes continuous mix of different people and personalities doesn’t lend itself to rigid adherence to firewall and LAN sub-netting policies. Then, add the fact that live remote production is much more than simply routing real-time video to air; it is the creation of real-time video that often requires the network layer to get out of the way while it is occurring.
The truck engineer needs to have a very good understanding of the IT realm, as that’s how the engineer constructs the desired client workflow. But that same engineer is expected to understand the real-time urgent need in getting the program on-air; missing that objective is disastrous to anyone who plans a career in the industry. So, in the truck realm, since the networking effort is a part but not the whole of the overall truck engineer’s effort, it is often referred to as IP networking on the truck.
The Computer Layer on Top
The digital wave has totally displaced analog video except at the very ends, with the conversion of light energy to electrical potential at the camera and presenting the scene captured onto a display. Some might still argue that some displays are quantitative or discrete, and thus digital, in how they light up the display. Analog was continuous and infinitely variable; digital is sampled into discrete chunks and restricted to a finite number of values. It is often hard to determine when a computer is doing traditional data-processing tasks and when a computer is masquerading as a video-processing box.
Computers exist in two camps: servers and clients. Servers do just that: they serve. Every time you visit a Website, your browser is dealing with a Web server that “serves up” Web pages and software snippets, HTML code, CGI scripts, and Java Applets that make up the page displayed. A server has to be able to handle lots of external requests and have lots of resources, including memory and storage. They must be fast, with enough redundancy and backup power supplies to ensure that they are up and running as close to 100% of the time as possible.
Your browser is the client to that Web server. It makes requests that the Web server responds to. Many systems today operate like Web servers. You find this synergy on trucks today, with Web pages that access other resources, like video files, television-router control, or truck-environment control. So Web servers can front other internal services in the computer, hosting the Web server or services on other computers. Services like databases that track all the media assets available or what every router’s crosspoint has selected as an input are examples. Other services can be video servers, which are specialized servers that play back video on request, usually more than one clip at a time. Another would be an SNMP server that would provide information on the status of equipment throughout the truck or even the whole compound.
A lot of equipment, even that which is not technically considered to be a computer, still has embedded Web servers. Often, these Web servers are the primary way to control and check the status of that equipment. Clients don’t have to be near the server. The truck vendor’s headquarters could have a client that looks at services on the truck.
What are some common servers and client partnerships on a truck? There is the video server, a centralized server talking to multiple clients throughout the truck. There is also equipment that has a Web server built in, where a browser on any computer in the truck could reach an SNMP server gathering info from SNMP-aware equipment on the truck. There are also graphics servers, where a powerful machine containing a graphics engine has software running to deal with requests and commands from users throughout the truck. Editing systems are similar, with a centralized video server that has high-resolution media and serves low-resolution copies, or proxies, to the editing stations. Here, edit decisions are made, such as clip in/out points, and then the EDL (Edit Decision List) is shipped back to the central server. The EDL is then used as a log to play out the clips in order and length when requested.
IP networking is pervasive not only across the media environment but in a vertical sense as well. It’s found at the top, as part of the control system, and at the very bottom, where the cables that connect one computer to another reside. This layering or stratification of various parts of IP-networking operation was codified into what is known as the OSI stack. OSI is short for Open Systems Interconnection model, a standard officially known as ISO/IEC 7498-1.