guidelines for wiring an office

Question

Does anyone have a link for recommended network wiring for office space? Runs per wall plate, wall plates per room, that sort of thing.

Answer 1

If you're willing to spend a little money, you can get the "bible" for cabling installers: The "Information Transport Systems Installation Methods Manual" from BICSI. It's $129.00, but it's got an unbelievable amount of detailed information.

If you're worried about legal compliance, check with your local electrical or building inspector. Most states don't classify "low voltage data cable" under electrical inspection guidelines, but you may have fire inspection-releated concerns.

Here are my personal takes on cabling:

• Run more cable than you think you're going to need. The wire is cheap, the installation labor is not.
• Use well-labeled wall plates with some kind of documented labeling standard. It shouldn't be complicated, but it should be documented.
• If you can, create an as-built drawing. It will help you (or the next guy) when problems come up.
• No matter where you put wall plates, users will put bookcases, desks, 1000 pound safes, etc, in front of them. Try and get in touch with the office space-planning people to see where good wall-plate locations would be.
• If you're still using traditional non-IP telephones, coordinate with your voice vendor to run a single cable plant for everything if you are able. You can plug RJ-11 jacks into RJ-45 wall plates. Some people say that it's not a good thing to do, but I've seen it done for years w/ no ill effects.
• Run more cable than you think you're going to need. >smile< Having to put switches in offices because you add IP phones, network-printers, and an Ethernet-attached camera where you thought that only a PC was going to be located is no fun.

Answer 2

For a typical high-tech office with less than 50 people, run 3 CAT6 cables to every office or workstation and terminate them as RJ45 walljacks. Make them all home runs back to your server room.

If you are using IP phones, terminate them all to RJ45 patch panels in a 2-post rack with your switches. If you aren't using IP phones, terminate 1 out of each group of 3 to a BIX patch panel. If you convert to IP later, it will be a simple matter or reterminating them to RJ45 patch panels.

Get a floor plan and number all of the walljack locations. Get it printed big, laminate it, and post it by your patch panel with a dry-erase marker.

Insist that your contractor test them with some sort of signal tester and not just a tone test. We found that about 1% of our runs were unusable for Gigabit Ethernet. Luckily, we have enough spare runs that we just left them broken and negotiated a 1% refund.

Answer 3

...from my personal experiences:

General info:
- the standard wallplate I use, has 2 RJ45-ports
- I recommend Cat.5e or Cat.6 cabling (a question of budget)
(should work with a wide range of services - Gbit/Phones/Extenders)
- Terminate all ports from the wallplates on a patchpanel in your techroom
- I tag the patchpanels with letters A,B,C,etc. - so I can tag the ports
at the wallplates with A1, A2, etc. - this makes the wireplan independent
of organizational changes
- make a floorplan with all ports on it (see other post above)
- if the wiring is done by an external company, etc. let them make a test
protocol for every port, to prove that they all work perfectly (see other post)

Officeworker: needs 4 Ports
- 1 for PC/Workstation
- 1 for Phone (analog, digital or VoIP)
- 1 for additional Laptop
- 1 spare (e.g. local Networkprinter)

Programmer/Techguy: needs 6 Ports
- 1 for PC/Workstation
- 1 for Phone (analog, digital or VoIP)
- 1 for Laptop/2nd Workstation
- 1 for testing (to set up the new Laptop of HR, etc.)
- 1 for multipurpose (admin-network, second phone, etc.)
- 1 spare

Room/Office:
- amount of people how will work there (see above)
- ports for central Networkprinters, Copiers, Faxes, etc.

Ok, enough text for now, have fun...

Answer 4

There's a lot of good advice here, but one thing I didn't see stressed enough is to leave extra cable in the wall behind the wall plate. You never know when, for some unforeseen reason, the wall plate will need to be relocated or the jack re-terminated. If you have an extra foot or two of cable neatly coiled up and tied behind the wall, this is an easy task. If the termination behind the wall plate has merely a few inches of spare cable, this may require a whole new run or simply make the task impossible.

Also, I'm going to go against the grain here and recommend no more than 2 jacks per workstation. Anyone who needs more than that is almost certainly sufficiently technical that a small 4-8 port Gb/s hub installation neatly mounted under or above a desk is unlikely to be a nuisance.

Answer 5

I just wired a new office suite for my company, and based on past experience we did most of the work ourselves. Here's what we did:

1. Worked out where the desks would be going now and might go in the future.
2. Ran Cat6 cable to each location, and where we had the walls open anyway, put in conduit to make any future upgrades easier.
3. Installed twice as much Cat6 as we expected to need.
4. Located wall plates at the same height as power outlets, more for tidyness than any building code reason.
5. Used keystone wall plates, with twice as many spaces are there were RJ45 jacks to go in now. Keystones are great, and in a pinch you can run additional cables and add jacks while a user is still plugged in to one of the other jacks!
6. Bought managed gigabit PoE switches. I know they're more expensive, but so is buying an unmanaged 10/100 non-PoE switch now and having to ditch it next year. If you're going for VOIP, you'll need these anyway.
7. Wired everything back to a patch panel, including lines to be used for phone or fax, so there are no conversion costs later.

Answer 6

In consultation with our wiring contractor, we did two runs per wall plate and there were two wall plates per room. This was just for network, we left our phone wiring as it was when we upgraded the network to Cat6. If I were doing it new, I'd use the same wiring for phones and I'd probably go with 3 runs per wall plate. 2 would save a bit of money, but I'd want the flexibility to have phone+2 network connections active on one plate.

Answer 7

Runs per wall plate, wall plates per room, that sort of thing.

Who's using these offices? If the offices are full of programmers, IT pros, and other technical sortss who are each going to want to wire their desktop, laptop, maybe an additional Mac or Linux box, plus some non-computer gegaws that need a network connection you're going to need a lot more ports than if we're talking about lawyers or accountants with one computer apiece.

Answer 8

Settle on a wiring standard. I tend to prefer 568-B but at the end of the day it doesn't matter which method you pick...just pick one and stick with it.

Edit:
I just thought of another small tip.

If you can try to pull the longer runs first. This isn't always practical but this will result in less wasted wire.

Answer 9

This is going to depend on what type of office how big are there multiple places the desk could go? What type of user will be using it. Will there be a separate network for VIOP. If you can start to answer some of those questions things should become clear fairly quickly.