FireWire supplement Ethernet-based networks as a viable
storage and networking system? by Dr Seamus Phan
you a home moviemaker who carries a miniDV camcorder
wherever you go? If so, you'll know that the best way
to archive all those wonderful memories is to convert
the miniDV tapes into a digital format such as DVD,
or perhaps VideoCD, if you are not too fussy with video
However, the process of converting tape data into digital
formats suitable for online non-linear editing (NLE),
as well as eventual deployment into multiple data formats
including QuickTime, RealMedia, Windows Media or
even MPEG4, can be tedious and complex.
What then, can organizations do to store audio and video
information, as well as provide high-speed bandwidth
to stream them to users, especially on LANs?
The answer may lie in a combination of IEEE 1394 (commonly
referred to as iLink by Sony, or FireWire by Apple Computer)
devices, and various digital format conversion software
running on alternative FireWire-based networking software.
bit on FireWire
IEEE 1394 or better known as FireWire, uses 64-bit
fixed addressing derived from the IEEE 1212 standard.
Each packet of information carried out contains
a 10-bit bus ID (for tagging which FireWire bus
the data comes from), a 6-bit physical ID (for
identifying which device on the bus initiated
the data transmission), and a 48-bit storage zone
(that is capable of addressing 256 TB of information
for each FireWire node).
FireWire nodes are best kept 4.5m or below from
each other to retain data integrity, and the total
aggregate distance for a series of daisy-chained
nodes should be 72m or less, with no more than
Just what is FireWire and why is it so interesting,
especially in a small departmental network that needs
to share very large files?
In a nutshell, sheer speed. FireWire can transfer data
up to 400 Mbps, which when compared to 100 Base-T Ethernet's
100 Mbps is four times as broad a bandwidth.
FireWire is also a plug-and-play data transfer protocol,
which means you can remove storage disks on the fly,
and plug them back when you want them. It is a daisy
chain system, which means that you link one device to
the next. FireWire connections can be powered or unpowered.
Computers that have built-in FireWire ports tend to
have powered ports, while removable disks tend to require
power from another source, such as a host computer or
a power supply.
To be able to share information using FireWire between
different computers, you cannot simply plug FireWire
cables from one computer to another and expect the peering
computers to turn up in your network neighborhood. You
need software that allows computers to "see"
FireWire as a legitimate data sharing protocol. One
such software is FireNet Software (www.unibrain.com),
which turns the FireWire port into a 400 Mbps data transfer
demon, and allows computers to use FireWire much like
With FireNet, FireWire connections operate exactly like
Ethernet, allowing all TCP/IP traffic to travel through
the FireWire port, including AppleTalkIP, FTP, http,
streaming and so on. Using FireNet, coupled with Unibrain's
FireNAS, you can easily move hundreds of megabytes of
data to and from computers, and easily archive them
to the NAS.
FireNet co-exists with Ethernet, and you can operate
two completely independent and redundant networks for
a small group of computers. For example, Ethernet can
still be used for general network and Internet connectivity,
while FireNet can be used in place of Ethernet for the
transfer of large files within the workgroup. FireNet
works with most modern flavors of Microsoft Windows,
and Mac OS 9 and X.
But because FireWire is daisy chained, it presents some
challenges when linking a network of computers together.
This means that you should not unplug cables that connect
from one workstation to the next, especially during
a day where data transfers are intensive.
Ideal FireWire work places
Some environments that can quickly realise the
financial and productivity benefits are graphic studios
and color separation houses, video post-production studios,
computer animation studios, corporate e-learning departments,
as well as bioinformatics laboratories.
If you do not require a FireWire NAS, you can also designate
one of the computers as a FireWire NAS. For example,
if you have a user who uses the computer for light-duty
computing such as word processing, and the machine has
sufficient data storage capacity (or can be easily upgraded
with another internal hard disk of 50 GB and above),
you can turn on file sharing through FireNet for the
rest of the workgroup to move files into and out of
this machine. Because file sharing is an inherently
insecure mechanism, you want to ensure that this arrangement
works behind a strict firewall implementation, so DHCP
and NAT are turned on.
This will create a parallel data sharing network over
the existing Ethernet backbone, without compromising
speed and productivity of the network.
Moving from tape to disk
Capturing video on DV tapes is easy, but the real
use of the video content is in mass distribution, especially
over a network.
Rather than shooting corporate e-learning or other communication
footage on DV tape, and then using a NLE (non-linear
editor) to digitize the footage from tape to a digital
format (such as QuickTime or raw DV data), there are
now FireWire devices capable of allowing real-time capture
of video to disk, without requiring the intermediary
stage of digitization.
There are some common FireWire DV disks, including DV
Bank FireWire DV Recorder from DataVideo (www.datavideo-tek.com),
and FireStore from Focus Enhancements (www.firestore.com).
Both disk recorders allow you to use a 4-pin to 6-pin
FireWire cable to connect your miniDV camcorder to the
disk recorder, and record directly to disk without recording
to tape first.
The DV recorders can be seen by computers as merely
another FireWire removable disk, typically without the
need for driver software. In this fashion, the DV footage
is usually in raw DV format, which most modern DV-compatible
NLE software can edit right away. For Mac users, the
DV footage can be imported into the iMovie software
without conversion, or use QuickTime to import the DV
footage and convert into MPEG4 footage.
Bringing video to networked desktops
QuickTime (www.apple.com/ quicktime) and DV are not
the most ideal formats for networked delivery and streaming,
since both formats are humongous in size. The current
favorite is MPEG4, which is a streaming and bandwidth
friendly video format suitable for networked delivery
as well as mobile devices such as cell phones and PDAs.
MPEG4, because it is a relatively new video format,
has several variations to make it incompatible with
different platforms. However, most platforms will accept
MPEG4 Simple Profile, the baseline for MPEG4, which
can scale from a baseline playback speed of 15fps (frames
per second) to 30fps.
PacketVideo, one of the oldest MPEG players in this
market, has PVAuthor (www.packetvideo.com), which is
an encoder capable of generating Simple Profile MPEG4.
PVAuthor also provides for automatic bandwidth negotiation,
necessary for scaling MPEG4 video up or down, depending
on the bandwidth of the playback hardware. For cell
phone and PDA playback, PVAuthor is the best encoder
Ligos (www.ligos.com) is another veteran in the MPEG
space, and has GoMotion, which produces the most compatible
MPEG4 Simple Profile footage suitable for almost any
For video streaming, it is important to have a dedicated
streaming server. If you are using a Mac running OS
X Server 10.2, you will have QuickTime Streaming Server
provided. It is technically possible to run a workstation
both as a client and a server, especially if the computing
is light, since OS X has true multitasking. But with
the rapidly decreasing costs of hardware, it makes more
sense to dedicate a full-time machine to streaming content
to other networked desktops.
Ethernet has become ubiquitous with most corporate networks,
but its purpose as a general purpose networking protocol
makes it less ideal as a bandwidth-hungry multimedia
streaming protocol, especially where resources in organizations
can be shared by hundreds of employees. With localized
streaming using IEEE 1394 or FireWire, corporate workgroups
can enjoy quality content streaming, and still have
their Ethernet fully functional for other connectivity
Seamus Phan is research director at KnowledgeLabs
News Center (www.knowledgelabs.net), an independent
technology news bureau and writes for Network Computing-The
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