Setting up a new network - How does this look?

Question

Hello,
Current layout of network - http://i30.tinypic.com/fkywav.jpg
We currently use this way of setting up our network and we may be moving to a new office so i'm looking at the best way of setting up the new network while we have a relatively clean slate. All wiring is done via CAT5e ethernet.
We run OS X Server 10.5 and use the following services within the building. File sharing, email, internet. We backup all machines individually with external drives but i'm looking at getting a large storage device to enable everyone to backup to one location using Time Machine Server.
I'd like to know if the way our network is currently set up is the correct way for what we need. In the near future i'd like to start using iCal sharing, and hosting websites internally for web development.
Regards
James

Answer 1

What you have will work; it's fairly typical network.
The physical plant, and the plans for expansion, and the current speeds and feeds are also key details when designing a network.
Cat5e? Don't skimp. Go Cat6 or better. Wiring is always around and in use for far longer than any of us want, and the cost of installation is comparatively vastly higher than the cost of the wire itself; retrofitting is to be avoided.
As part of avoiding unnecessary retrofitting, run extra Cat6 or better wiring in parallel, too. Prepare to segment your network based on business organization or on physical organization, or both. The extra runs can provide physical redundancy, and bandwidth. The incremental cost of building out with extra (spare) wire is negligible. The cost of not having a wiring run where you need it is higher.
Without knowledge of the physical plant, I'd also look at the establishment of wiring closets and such; you'll usually have a star at the core of the network in a smaller configuration, then stars at the wiring closet(s) (if any) and out at the desktop. This may be a plan now, and you have the wiring in place for the main runs to retrofit a server closet as you need it. Long wire runs out from the core are a pain. In a moderate or larger network, you'll be using the backhaul connections to the network cores; runs between server closets. (And if you may add server closets, remember the need for cooling can arise.)
Depending on your plans and your network activities, I might (also) establish higher-bandwidth wiring between the wiring closets; what amount to backhaul connections. Either used up front, or in the closets should you need to place switches further out.
Also look for corner cases, such as a business and operational environment where you'll be running a dozen or two client netboot operations at exactly 8:01 each and every morning as each staffer arrives and boots up the workstation; these cases can play havoc with aggregate bandwidth and server requirements.
You may want to consider a parallel network (whether WiFi or wired) for guest access; a conference room or conference center network. You'll almost certainly want 11G and 11N WiFi for your own internal use, too.
Yes, I usually overbuild these things. Planning and wiring are (comparatively) cheap. Installation isn't.
Backing up to a Mac OS X Server disk or a TC disk via TM is part of what you need. If you get corrupted archival volume(s) or if your RAID array is somehow damaged or lost or stolen, you're in deep sneakers. I've had a couple of TC archives corrupted; stuff happens. Plan for off-site archives.