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created 23 April 2000

No matter how fast your network is, as an admin, you will always get the call for more speed. If you have switched 10Mbps lines to the desktop, you'll get the calls for 100. If you put 100Mbps to the desktop, you need Gigabit. I can guarantee you, no matter what you do, the network will never be fast enough for some folks.

Making things even harder is the never-ending array of new technologies that will make you network so fast, you won't even need hard drives in your Macs. Gigabit Ethernet, ATM, FireWire networking, Fibre Channel, high-speed switching, vLANS, the list is almost endless.

However, just blindly throwing money at a single solution may give you more speed, but it may also ignore the problems you are really having. Each of these technologies has a place where it fits better than others, and each of them has problems related to it's design and / or relative maturity.

First of all, on the desktop, you are going to be limited in what you can use. These days, the newer Macs all come with 100Mbps Ethernet, so that's a pretty good place to start. Most of your standard Ethernet equipment will handle switched 100Mbps without a lot of extra cost. Although you can use 100Mbps hubs and save some money, the shared bandwidth of a hub will give you less of a speed increase than you get with the dedicated bandwidth of a switch. Also, switches give you more configuration and management options for things like vLANS, and segmenting.

The next question is what about servers? This gets tricky, due to some limitations in the MacOS's networking architecture. The biggest problem is that the Mac cannot inherently have more than one active network interface per protocol. There is an exception to this in AppleShareIP, but that is strictly limited to AppleTalk, and AppleTalk's future is somewhat limited. Although OSX will lift this, for now, if you want more than one interface without third-party add-ons in the current MacOS, you can't do it.

This does not mean that you shouldn't consider higher-speed interfaces for MacOS servers. For things like print servers, RIP servers and the like, a Gigabit Ethernet card is still a good choice. One reason is that with a Gigabit card, the server can handle ten 100Mbps clients at full bandwidth. With some clever uses of switching, you can keep that Gigabit interface working at full speed, giving you maximum use of the available bandwidth, which in a heavy use environment can save you quite a bit of time and money.

Another area where higher-speed interfaces can help is with file servers. Technologies such as Fibre Channel allow you to set up disk arrays with access speeds that rival most SCSI implementations, and without the baggage that SCSI still carries, such as termination, LU numbering, etc.

In combination with a Gigabit card, you can get greater efficiency for all users of the server by eliminating bottlenecks on a few select Macs, and save money over reconfiguring an entire network. (I have seen too many servers with insanely fast disk arrays that are then attached to the network with 10 or 100Mbps connections into an almost-full hub, and everyone scratching their heads over why things aren't faster. )

Another advantage of Fibre Channel is that since it was first designed as a networking protocol, it can help you set up a Storage Area Network, or SAN. The advantage to a SAN is that the drives are not 'assigned' to a specific computer host, but exist as their own entity on your network. You can then have multiple servers accessing the same drive array, without one of them being dedicated as a file server. SANs are also OS independent, so if you have Windows NT/2000 servers, or Sun Solaris servers, they can easily access drives on a SAN as well.

FireWire is another interface that is coming into its own as a networking implementation. Recent announcements from companies like VST, MicroNet, unibrain, and others are showing that in addition to just being a way to get things like video into a Mac, FireWire can allow you to set up high - speed networks, or SANs with relative ease. Although FireWire is limited in the number of devices on a segment compared to Ethernet or Fibre Channel, the fact that all Macs come with it is a compelling reason to consider it, especially for server - to server communication. FireWire is also host and OS independent, so devices on a FireWire network can operate independently of any other devices, and do not need a host server.

Backup is another area that bears careful analysis for network speed. In this, the infrastructure of the network is more important than the interface speed on the backup server. This is mainly due to the relative slowness of the backup media and the backup process. Due to the stop / start nature of the backup process, and client load, even a fast tape drive will have trouble sustaining speeds in the 100Mbps range consistently. So for more efficient backup servers, you are better off ensuring that all your client Macs have clean, switched, 100Mbps connections. This will give you better overall results than slow connections on the clients, and a Gigabit card in the server.

Although I have mentioned only the current MacOS in conjunction with these products, there are Gigabit Ethernet solutions available from TeamASA, and Fibre Channel solutions from Micronet and Hammer that will run under MacOS X Server as well. Considering features of OS X Server such as NetBoot and QuickTime Streaming Server, getting as much speed from the hardware as possible only makes sense.

In the end, planning your high-speed implementation is as important as the implementation used. By carefully considering which technologies are best suited to the tasks at hand, you can greatly improve the speed of your network, without breaking your budget.

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