Firewire or Gigabit Ethernet?

schvenk asks: "Firewire (IEEE 1394) has been accepted as a standard for peripherals, from hard drives to CD-RW drives to digital video cameras. It's a 400 Mbps technology. At the same time, many machines are shipping with Gigabit Ethernet, a 1000 Mbps equivalent of an more widely accepted standard. I'm not a hardware guy, but at first glance it would seem more efficient to eliminate Firewire altogether and equip peripherals with Ethernet ports, ultimately moving all wired communication to a unified standard. Am I missing something?"

Comments

Firewire vs. GigE

[renehollan]

While the prospect of a single universal physical network layer is appealing, here are some realities that interfere with this.

1) Applications. Ethernet was designed as a shared medium to support arbitrary contentious traffic framed in a simple data link layer, sent between relatively distinct systems. It is intentionally a small, simple spec. Firewire was designed to provide connectivity to high-bandwidth, real-time traffic in a local environmment. Firewire therefore supports notions of bandwidth reservation, and was initially geared to short-haul distances (i.e. on the desktop, or in a small equipment rack). It is a more detailed and involved spec because of an intended techno-ignorant consumer audience -- plug things in and they work.

2) Power. While PoE (Power over Ethernet) is gaining steam, driven mostly by the notions of IP telephones and other networked devices without local power, ethernet generally does not carry power. Firewire can, to simplify cabling.

3) Bleedingedgeedness. Firewire was bleeding edge. In order to be cost-effective at some level, compromises were made. Initial distance limitations (on copper) were severe. It was bandwidth at all costs. Even today, firewire does not strike me as effective for long distances (need for fibre vs. copper). GigE took longer to develop because of the need to work at extended distances (100m being the traditional ethernet radius), with a copper physical plant, and the lack of comsumer device pull. It also had legacy inertia to deal with.

In my mind, the biggest difference, though, is the nature of the intended traffic: Firewire addresses bandwidth reservation, and ethernet doesn't. To be sure, one can layer the necessary protocols over ethernet to do this, but then ALL the traffic has to be managed outside the ethernet spec. to honour those protocols. Firewire has the promise to be a micro-local, cheap, real-time networking solution. Ethernet addresses longer distance needs with a diversity of traffic types.