Broadcast companies embrace Fibre Channel over fiber
Broadcast companies embrace Fibre Channel over fiber
Early adopters of Fibre Channel like its ability to transfer large files at high speeds?and the growth path offered by fiber-optic transmission.
Stephen Hardy Editor in Chief
Much of the excitement that surrounds the Fibre Channel protocol derives from the potential to link multiple data storage facilities into a network of shared resources. This concept--alternately called "storage area networks" or "storage attached networks" (SANs)--encompasses the ability of a single workstation to access several storage towers, or multiple workstations to share access to a single storage facility, through a gigabit-speed network organized around Fibre Channel hubs or switches. Naturally, when you`re talking about passing large amounts of high-speed data over networks that could reach campus size, you also envision that the foundation of these SANs will be fiber-optic technology.
With Fibre Channel still in its infancy, however, much of this promise remains unfulfilled for all concerned. Fibre Channel equipment is just beginning to approach the availability and price points necessary to attract the attention of the user community. And not all of the users who are paying attention have determined that their applications need a SAN. Finally, with SANs frequently expected to cover short distances, both users and vendors have questioned whether fiber optics will be necessary in more than a handful of applications for the foreseeable future (see Lightwave, January 1998, page 35).
Yet, there are signs that SANs have found a home in at least one applications area: broadcast television and motion picture production. Production houses may prove the breakout application that propels Fibre Channel SANs into widespread use--and both the users of these networks and the vendors who have installed them are sold on fiber-optic technology.
Big pipes for big files
When the American National Standards Institute began work on Fibre Channel in 1988, proponents envisioned a protocol that could be used in a wide variety of applications to support multiple protocols through the same port and across the same high-speed communications channel. Fibre Channel architectures can support point-to-point, arbitrated loop, and switched topologies, and vendors foresee three main applications: storage, clustered networking, and general communications networking. These applications would take advantage of Fibre Channel`s high-speed capability; the initial standard carries a 2-Gbit/sec ceiling, although currently available equipment tops out at 1.0625 Gbits/sec.
Storage, in the form of SANs, has been the first of the three major application areas to attract significant user attention. Fibre Channel offers a clear upgrade path from the SCSI protocols that have dominated storage environments; even enhanced SCSI architectures, such as Fast Wide SCSI, offer a maximum transmission speed of 200 Mbits/sec. In addition, Fibre Channel will support 16 million nodes, compared to the mere 16 of SCSI.
Thus, the makers of Fibre Channel equipment can offer a lot of networking horsepower--the trick is to find someone who needs it. Enter the broadcast production industry, which has seen a revolution in the way commercials, TV shows, and movies are produced, edited, and composed. "This whole industry over the past five years, not just broadcast design but television and video production in general, has moved from tape-based editing to computer-based editing," explains Mike Andrews, president of Gotham Pictures (New York City), a broadcast design house that recently installed a Fibre Channel network to link its editing workstations.
Until recently, production houses worked exclusively with videotape. If different people had to work with the same tape (or if the programming on multiple tapes needed to be merged together), copies were made and passed from person to person. The quality of the tape deteriorated each time it was copied. With the advent of digital editing, however, original tapes are digitized for editing using software provided by such companies as Avid Technologies. The digital programming or effects can be stored on hard drives for access by computer-based users.
But even this advance proved less than ideal because sharing large files (a 30-sec commercial can require 20 to 30 Gbytes of data to create, says Andrews) could be difficult. Most of the options available to Andrews left him unimpressed. "Fast Wide SCSI is speed-wise okay, but when you have three or four different people working on the same project, which we do, it`s very difficult to get multiple gigabytes of data from one system to the other," he says.
Ethernet also falls short because the video file sizes are too big--and the storage requirements double because you copy from one machine to the other, Andrews relates. File transfer speed also is an issue with Ethernet. This particular issue left Andrews with the option of using removable SCSI drives and walking them from one machine to the other--a solution with obvious limitations (as well as not-so-obvious problems, such as the fact that the image finders on different machines are not necessarily synchronized, which makes finding the right image more time-consuming).
"So what we`ve been looking for, for a couple of years, is a system that allows all of us to work on the same central storage, have access to that central storage, and have the speed that we needed. And, hence, Fibre Channel fit that need," he concludes.
"I think the bottom line is speed, whether it is the speed as it relates to the efficiency of completing productions or just the efficiency of moving data between productions," offers Gerald Smith, president of Premier Communications Inc. (Kansas City, MO), a post-production services vendor that also turned to Fibre Channel. Like Gotham Pictures, Premier had used a tape-based system before it adopted all-digital editing technology.
Networked storage via fiber
Like many early adopters of new technology, both Andrews and Smith found it difficult to find exactly what they wanted when they decided to give Fibre Channel a try. "There was a whole bunch of people two years ago, at the NAB [National Association of Broadcasters] show, who announced that they were going to provide Fibre Channel products," says Andrews. "There was only one that had one that you could buy."
"We found that there wasn`t that much on the market," agrees Smith, who began his investigations about a year ago. "There`s a lot of data-manipulation [capabilities available], but we`re talking high-bandwidth, real-time broadcast video playback with no room for error."
However, they each found a vendor (in both cases, Transoft Inc. of Santa Barbara, CA) and moved forward with a Fibre Channel implementation that accommodated their existing production hardware. In Smith`s case, this involved linking four workstations with a pair of RAID data-storage towers carrying a total capacity of 140 Gbytes. Two of the stations are graphics workstations (including one for three-dimensional effects), while the other two are used primarily for editing. This arrangement allows a person in one room to create a three-dimensional graphics effect, another to edit the background footage against which the effect will be shown, a third to composite the two files together, and a fourth to add the finished product to the master file.
"We all can work on the same drives, we can all share those files, and it just saves a huge amount of time," says Andrews. "It has been, up to now at least, a big advantage. We can do stuff much faster, basically. We are sometimes asked to do stuff in ridiculous time frames, where it really does require two or three or even four people working on the same thing at the same time."
The logical extreme
Meanwhile, Premier Communications has taken the digital concept to its logical extreme. Whereas most houses record programs on videotape, then digitize the tape, Premier runs its video signals directly from the cameras within its in-house sound stage into its storage facilities. Thus, any one of the five workstations hooked to its Fibre Channel network can access the stored program immediately after shooting has finished. Given the size of the files involved, a large amount of storage capacity is essential. In addition to two RAID towers with a combined 144 Gbytes of storage, individual caches at each station range from 36 Gbytes to more than 70 Gbytes.
"It`s just gotten out of control. It`s all about memory or storage," says Smith. The ability of the company`s Fibre Channel network to accommodate large data files has allowed Premier to use data storage as a competitive advantage. "Because of the ability of the Fibre Channel system, it`s kind of like renting out real estate. We have more and more clients wanting to keep all of their commercials and bumpers and corporate ID logos and all that stuff--they want to keep that here all of the time. So they can just walk in and be ready to go; they don`t have to re-input data. So ongoing clients, we almost basically just rent them out storage. So that`s why your storage [need] continuously increases," he explains.
In addition to enjoying the benefits of Fibre Channel, the two applications also share another aspect--the high-bandwidth capacity of fiber-optic cabling. "There was a choice on our cabling whether to go fiber or copper," says Elizabeth Narmore, Transoft`s marketing manager. "And we`ve just maybe within the last month decided to go all fiber because there are link restrictions with copper. You can only go 20 m--that`s what we were selling. And once you wind it around and if you daisy-chain--if you have more than a couple of storage towers--you`re kind of limited as far as you can go. And too often things are in different rooms, bigger rooms. So it just was better [to turn to fiber]."
Transoft uses one-pair 50-micron multimode cabling from AMP Inc. (Harrisburg, PA) for its applications. Narmore reports that the company has tested 62.5-micron cabling but currently prefers 50-micron fiber because it affords greater link lengths.
Hubs versus switches
One area of contention that has appeared early in Fibre Channel applications is the question of whether to base a user`s new network on a hub or a switch. For example, the four-seat network at Gotham Pictures runs through a hub.
"We wish we had a switch, to be honest," admits Andrews. "The hub is fine, but it`s still software arbitration as to who gets to write to what, which is not the best way to do it. It works, but it`s not ideal. A switch is a better way to go and we know that. And the good news about that is that the switches are coming down [in price]. Switches were prohibitively expensive when we first got into this, and they`re getting better."
"Most people will purchase a hub over a switch," reports Narmore. "We would recommend [a switch] for the larger networks, but understand a switch is like $50,000. So you`re talking about a huge, huge price increase." Transoft`s in-house expertise centers on networking software, so it acquires its Fibre Channel hardware from original equipment manufacturers. It currently offers a 7-port hub for $1995 and a 10-port optical hub for $3995. But while a 4-port fabric switch starts at $18,000, the most commonly used switch, a 16-port unit, costs $50,000.
Smith paid the extra money for a switch at Premier Communications after starting his Fibre Channel experience with a hub. In addition to offering networking efficiencies, the switch offers more flexibility by allowing systems to be dropped or added to the network easily "if you want to take one offline and not risk anything else," Smith explains. "Or let`s say you have a problem with something or you need to do installations on one, it just gives you the ability to shut that one off."
The future is Fibre Channel
While both Gotham Pictures and Premier Communications acted quickly to bring the benefits of Fibre Channel to their companies, the presidents of both production houses see the use of Fibre Channel spreading throughout their industry.
"We were the first to move [to Fibre Channel] in this Midwest region," says Smith. "All of our major competition has moved to this system [since then]. It`s almost like a standard--it`s moved from an option to a standard. I mean, it`s come to be expected in the post-production industry that you have some sort of Fibre Channel connection."
"Certainly anyone who is building a new facility is thinking this way" concurs Andrews. "I think Fibre Channel is going to be the workhorse of what I do for a while."
However, the technology must continue to mature--and, in particular, prices have to drop--before the technology becomes ubiquitous, Andrews adds. "I think to get into the technology for people like me, the stuff`s got to be [less expensive]. Of course, it`s going to cost more than Fast Wide SCSI, but it shouldn`t cost that much more. And when we got into it, it was just at the point where it made sense. And now the prices are getting to where they need to be in order to take off," he says.
For example, Andrews says that a Fibre Channel switch would have to cost between $5000 and $10,000 before it reached his "ideal" range. "As things get more mature, I`m assuming that`s going to happen rather quickly," he says.
Meanwhile, putting the fiber back in Fibre Channel will help users extend their capabilities in the future, Andrews predicts: "The thing that`s most intriguing about Fibre Channel is the ability, someday at least, to tap into fiber that`s running in the street and to be able to link to somebody a mile away. And I think that in five years` time, that`s going to be a big issue. And the fact that there is the potential of that down the road, with the system we have, had something to do with my decision, certainly." u