What's a good place to buy networking gear?

No-one installs hubs these days -- it's too difficult to find hubs now... even most devices marketted as hubs are really switches.

I can't think of what you mean by a "bus" with respect to networking. The "bus terminators" suggests to me that you *might* be talking about coax cable terminators. That would, though, not fit in with your mention of cat 5e. cat 5e cable does not use terminators. Fibre doesn't use terminators either, just plugs to keep the dust out. You do "terminate" fibre at a patch panel though.

The standard configuration for what you describe would be to have switches on the other floors, with the systems connected to the switch on their floor and with connections going from the floor to the central switch. The intra-floor connections sometimes need to be fibre, if the building is fairly big, to avoid exceeding the 100 metre limit. (In our building, with two wings each of four floors, no run actually exceeded 100 metres, but some of them get fairly close {87-94 metres} so we used fibre between the wings to avoid marginal connections and round-up due to physical routing needs.)

When you ask about "gear", are you asking about the switches as well as the cat 5e and associated faceplates and patch panels? If so then in order to make a recommendation we would need to know a lot more about your networking expectations -- e.g., speeds, need to prioritize, special latency requirements, what LAN management tools you are planning to use.

the building in question is 3 networks. One is the Point of sale network where i don't want any slowdown. The second floor is the office/acct computers. The third floor are packaging appliances where network speed isn't important since the network access is only needed to update their individual databases.

But i rather just have gigabit ethernet all over the place. using hub/ switch/bridge to segment the 3 places (depending on what's cheaper, how many ports i need, etc.)

but since i'm lazy i just want to serially connect the 3 computers in the office together. I've read somewhere that i need a terminator plug at the end of the cat5. so it's one line to the hub, have that connected to a wallplate, then use another line to connect a second wallplate to the first wallplate. Bus network eh.

You would likely have to get a gigabit ethernet hub specially made for you -- there are no known gigabit ethernet hubs on the market.

A switch is a multiport bridge.

Three different computers in some offices? That are logically connected to the same network or to different networks?

I don't recall that that is the case. What I seem to recall is that the modular plugs require some kind of active electronics built into them, but I cannot seem to tease out the details at the moment.

If memory serves me properly, you "shouldn't" do that for 100 Base-TX and it is Not Allowed for 1000Base-TX. It's complicated enough for 100 Base-TX as that kind of connection would require using half duplex (full duplex assumes that the wire is not shared.) With 1000Base-TX you would not be able to negotiate the clocks correctly and It Would Not Work.

What you need for gigabit is a star topology, one network drop per system (unless you put a switch in each room -- and switches cheap enough to do that tend to be unreliable and impossible to monitor.)

holy crap. so if i need 10 computers network in one room, i need to daisy chan 3 or 4 switches? there's no way to use serially connect 4 computers to one switch port?

Gigabit switches are available in 5 port, 8 port, 12 port, 24 port, 48 port, and probably some other sizes; you can also add GBIC or SFP connectors into the mix. (The chipsets tend to be 4 ports plus one set of wires for connecting to the next chip; the 5 port switches connect a port to that 5th set of wires, but once beyond that the crossconnects get used to tie to the other ports, thus leading to multiples of 4 ports.)

5 and 8 port gigabit switches are available as commodity items from Frys or Future Shop or the like. 12 and 24 port unmanaged gigabit switches are available from Linksys and similar manufacturers, through standard distributers.

However, if you are talking about having 10 computers in one room, and multiple rooms over several floors, then I would recommend that you think carefully about network management facilities. For example you mentioned that the network on the first floor is to have high priority; if you find that that isn't happening, how are you going to investigate where the bottlenecks are, or which system(s) are at fault? If you have a production network where timing is important, then you probably cannot afford *not* to use managed switches and appropriate monitoring software.

my main concern is how many computers can one port on the switch support. for the mission critical 1st floor, i'll probably dedicate a port for each workstation. here's what i got so far.

1F 8-port switch(2), camera multiplexer(1) surveillance cameras(4), workstations(4), file server(1), repeaters(1) 2f 5-port switch(1), wallplate, workstation(1), appliance(2) 3f 5 port switch(1), wallplate, workstation(1), appliance(2)

is it okay to use the fileserver to also recieve the camera feeds? And to do network monitoring? Space on the 1st floor is tight.

(snip)

While 'hub' is often used in place of 'repeater', the words do have distinct meanings. Since the first hubs were repeaters, and the word is shorter it often got used to mean repeater.

In any case, the existing gigabit hubs, describing the topology of the wiring, are switches (or bridges) describing the logical function.

-- glen

Begin On Wed, 20 Feb 2008 23:56:41 -0800 (PST), Fornoman wrote: [snip!]

With current star topology ethernet? One.

That is, one cable connects two devices. If you have a switchport here, and N devices on the other side, you can insert another switch to fan out the ports. Within limits, up to some maximum, don't endlessly chain switches, and so on and so forth. There are good reasons not to insert switches if you can avoid it, say by buying a bigger switch.

The whole bus thing (10Base5 (`thicknet') and 10Base2 (`thinnet', `cheapernet') and associated taps and terminators) went out the window quite a few years ago. So I think that the information you've been looking at is a little outdated.

If you lay the wiring it's probably easier to plan where you need drops now and likely in the future, and lay cable to a central patching point (usually a patch panel in a wiring closet). Then you install a switch with enough ports and some spares next to it.

You can do that for areas spanning up to 100m cable. If the cables get longer, you carve out multiple areas spannable by less than 100m cable length between switch and device. Each area gets a switch, and connect the switches together. Between the switches you use copper if they're close enough to each other (100m cable length again), otherwise fibre.

Using one big switch means you can invest some money in it and use one that is manageable, supports vlans, monitoring, and all that.

I have deployed lots of small cheap switches like you propose in the past, but will refrain from doing again (even then it was a bit of force majeure). Those cheap small switches have interesting failure modes and even normal operation might requiring some coaxing and jumping through hoops. They really are cheap and you get what you pay for.

It might be fine, or it might not be. It depends on the traffic those cameras would generate and whether the network and the fileserver can deal with it. From here, it's hard to say.

thanks, guess i wont' go the cheap route. one last question. the star topology is okay for other rooms but i'm still worried about one point of failure on the first floor. is it possible to buy 2 switches, split the first floor's duties among them, and put a cable between them and have the fileserver connected to both. that way, there's always a path to the fileserver. i'm not sure what the technical term for this is called though.

Begin On Thu, 21 Feb 2008 07:15:34 -0800 (PST), Fornoman wrote: [snip]

Yes, and no. There are things you can do to provide redundancy, but it's not straight-forward and I'm not entirely sure what you're asking as you might be asking one of several things.

I'd advice two things, however. First, consider that a reasonable quality switch has a higher uptime expectation than your fileserver. So it may not be prudent to spend lots on redundancy in your network when the real weak point is your fileserver.

Second, it's probably wisest to get you someone knowledgeable on site and have a professional ferret out all the requirements, their consequences, and hammer out a reasonable design. If your infrastructure truly is critical, it'll be worth the expense.