Hardware Networking FAQs?

TufelKinder asks: "Our company is installing a new network at a new building location. There don't seem to be many discussions that center on the best cabling systems, etc, to use. I'm wondering what /. folk have found to be the best brands/types of copper cables to use for 10/100BT networking and for gigabit over copper as well. Are there any specific types of cable or cabling practices to avoid?"

Comments

Some advice...

[cmowire]

I am not a network expert, so take this with a grain of salt.

Get the best cable you can get at a reasonable price installed everywhere. Don't get the super-duper-will-be-good-for-1000-gigabits sort of cable. But do wire the desktops with a decent Cat-5e that will let you run gigabit when the price comes down for it so you don't have to do it again. And you know that, at some point, many users will start to need gigabit performance on their desktop. It's inevatable.

Make sure that you follow fire safety code. Only certain types of cable can be run through the walls.

Cable management is a very important consideration. The best system is one that lets you add more wiring whenever you want, keeps the cables neat, etc. I know part of it is making sure that you have ample conduit space through the walls, so you can run more cables later on. I know that another part of it is having those faceplates that let you add more jacks.

Do try to wire every room, even if it seems stupid. You never know what will happen later on.

Don't run everything through the same conduit set. Running power cables next to network cables is dangerous, stupid, and not good for network reliability. I think that's also against most building code.

You might want to wire the phone cables with Cat-5 or better, stupid as it seems. IP telephony is taking off and those might end up being used to wire up netphones.

Get a raised floor where all of the servers and hubs will be.

Try to have things set up so that you have no long cable runs. This may mean several networking/telephone closets. I'm not sure what the good maximum length is, so somebody else will have to fill that in.

Keep a map of what is cabled where. And keep it up-to-date.

Re:Some advice...

[sharkey]

Phone cable: The price between CAT-3 and CAT-V is very minor, and it does give you room to grow.

Gigabit "ready": Compare prices between CAT-V and CAT-6. Clean underpants, then run CAT-V. GB to the desks is probably overkill, but if you really need it, it's gonna cost you, whether using copper or fibre.

Raised floor: If there are other tenants below, running the entire network through the floor/drop ceiling below gets to be a pain. It is nice in the equipment room for in-room connects, for keeping the floors uncluttered.

Length: 10/100bTX is spec'd at 100 meters max.

Running with power can be done, but you need to use shielded cable (Price goes up).

Fire code: Here in INDY, you can run PVC or Plenum through the walls, but you can get written up for running PVC through the building plenums.

We are moving in December of this year. We get one floor in a multi-story salt-mine. We are running cable-trays through the drop ceiling, above all "aisles" in the cube farm, with wire-mold running down the structural supports to each cube "island". It is mostly an open-plan slave-pit, with filing, electronics, and kitchen in the center, and private offices at each end. We will not have to run thick bundles of cable over/through walls, or climb over cube walls, either.

Private offices will have 2 net drops (not necessarily 2 ports on a switch), the conference rooms will have multiple drops based on size, to accomodate furniture movement in the future.

Cable management and mapping is like commenting your code. Do it clean and keep it documented! I had to pull out a bunch of old 2-pair cable from our RS/6000 when it left. The bastards who ran it made it very pretty in the ceiling and floor by cable tying it every 3 feet in bundles, then to whatever was handy: ceiling supports, ceiling tile hangers, light fixture, power conduit, etc. Pain in the ass to pull out.

cat5 for short runs, fiber for the long haul

[biot]

Make sure you plan some space on every floor for a wiring closet while you still can; more than one for larger floors. Place them so you don't have to do more than about 50m from the closet to workstations. Use cat5 cable from the closets to where people will work. If any consultant or network type tells you to use cat6, fire him.

Plan for at least four patches per desk; people will bring in laptops, or put double the number of people in an office. Don't forget the absolute minimum is two patches per person (computer, phone), and the minimum will last you about a month before people start bringing in little hubs to put on their desk (which you want to avoid).

Between the wiring closets, use fiber. It's not as expensive as you may think, and terminating is quite painless -- many switches have fiber ports or room for fiber modules. You can also use fibercopper transceivers, not too expensive. Use single mode (SM) fiber. You need to do this because a) it can go much longer distances, b) you can happily string it alongside power lines if you need to, and c) because you can upgrade uplinks to gigE without worrying about the cabling.

You'll also need to get copper into the wiring closets though, for connecting the PBX to the phones. Distance isn't such a big problem for those.

If at all possible, get double the number of fiber links that you strictly need. Ideally, string it on different sides of the building or floor. You can't crimp it like you can cat5, and getting fiber types in for a splice takes a while. In a pinch, when one gets cut, it's good to have a guaranteed extra link ready, which is undamaged through following a completely different route.

In the wiring closets, put switches, not hubs. Don't use hubs at all, in fact.

Don't forget that the big cost in laying wire (both cat5 and fiber) is in man-hours, not the terminating equipment or physical cable. Putting in 10 cables isn't that much more expensive than putting in 1, in other words.

Re:Why avoid little hubs ???

[cmowire]

Generally, you want to avoid little hubs because:
1) Cheap little hubs tend to have short lifespans, break, have conflicts, etc. They are intended for people's houses, dorm rooms and impromptu networking, not for a business.
2) Little hubs don't perform so well compared to more ports on the managed switch.
3) Not everybody who needs multiple computers is tech savy. Take, for example, the salesperson who has a laptop for the road and a desktop for work.
4) You don't have all of the encryption, authentication, etc. options available for the little hubs.
5) If the little hub gets messed up, you have to walk to the cube instead of doing everything through a remote admin console.
6) It costs very little more to run the 3 or 4 drops than it does to run 1 drop. Cable costs pale in comparison to labor costs. It will cost much more to install more drops later when the hubs get to be too annoying.
7) Managed switch ports, for a good-sized network, are generally pretty cheap. Once you consider the potential hidden costs of a little hub (extra admin trouble, compatability problems, etc) it starts making sense to just use the managed switch ports.