Recommendations for the design of the physical plant

Consultants are often placed in a position to provide advice to a client that is moving into a new space or planning major changes to their facilities. Architects, mechanical engineers, and telecom providers do not provide enough guidance to steer our clients in the best way. Whenever you find out that one of your clients is planning a move or major redesign, you must get involved as quickly as possible. We must provide advice that will keep the long term goals of our clients in mind.

Cabling

In Cabling: The Complete Guide to Network Wiring, 3rd Edition (ISBN-10: 0782143318 and ISBN-13: 978-0782143317), the authors outline some of the “Golden Rules” of network design. The ones that are most important when advising our clients are:

• Networks will never become smaller and less complicated
• Build one cabling system that will accommodate voice and data
• Always install more cabling than you currently require

Installation of cable during the initial build out of an office space is always going to be the cheapest time to install cable. If the installation is taking place before drywall is installed, the cost of cable runs is even cheaper. Prior to moving into a space, the cable installers have full run of the space, meaning that they can take down tiles, drill holes, and string cable very quickly and easily. After the space is in use, they have to work on the weekends, move furniture, cover equipment, and work around other inconveniences and that doubles, triples, or quadruples the cost of stringing cables during the build out.

This makes the cost of changing your mind later extremely expensive compared to running additional cable. It may be wise to use a rough rule of “you need 2 so install 3” for all wall jacks and cabling runs.

Make sure that every cable drop – phone or data – is a CAT-5e or CAT-6 cable terminated to a female RJ-45 jack at the wall and a female RJ-45 jack in an industry standard, rack mounted patch panel.

You must stringently resist any deviation from this standard arrangement. The only exception you should allow is using smaller patch panels or patch panels mounted in small swing out wall mounts. In no case should allow CAT-3 cable to be run to workstations.

Note: the cabling book referenced here is an excellent source of information about cabling systems.

PBX systems

At one point in time, the installation of a PBX was almost completely irrelevant to the most consultants. However, there have been too many situations where the company specifying, supplying, and installing the PBX has interfered with networks.

Traditional digital PBXs run off of CAT-3 cable and RJ-11 plugs and have done so since the first PBXs were manufactured. In a traditional installation, the PBX is installed on the wall, cables are run into nearby W blocks, and those W blocks are hard wired to a CAT-3 line that runs to the office floor. That hardwires a particular place on the floor to the PBX system. If you want to change the extension, you go into the PBX software and change it.

It works fine that way but there are some problems. That CAT-3 line running out into the office cannot be used for anything else. There is no modern network protocol that can run on CAT-3 so you can’t hook up a phone. Also, the software for modifying a PBX is normally a proprietary, hard to install, and hard to learn software so any changes normally require a PBX technician. At one client, each desk move or extension change requires a $150 PBX support call.

There is so much history and industry inertia built up that installation model that you will practically have to threaten force to handle it differently. For all of our clients going forward, you should ensure that the PBX “output” is connected to a patch panel. Then you can patch the extensions to the floor just like any other patch panel. RJ-11 male connectors will fit in RJ-45 female connections so that the cable running to the office is irrelevant to the phone system.

Wiring the office this way turns every wall jack in the office into a multi-purpose jack. Also, desk moves require a simple swap of patch cables.

Cooling

Servers are very sensitive to heat problems but the upfront cost for dedicated cooling can often be daunting for our clients to pay for. However, we have several clients where overheating has lead to thousands in troubleshooting costs because problems caused by heat are intermittent, hard to diagnose, and are often camouflaged by other issues. The long, drawn-out, multi-crash server failure I dealt with was probably related to heat issues but that can’t be proven – even after spending over ten thousand dollars trying to figure out the failure and recover from it.

All servers require 24x7x365 cooling of some sort. During the design and planning stages, we should always push for dedicated air conditioning for any self contained server room. Cost of installation prior to people moving in is always going to be cheaper than after the office is up and running. Only if the client can truly not afford cooling, should we accept a dedicated, always on, direct vent to the outside extraction fan.

Each server puts out about 1.5 to 1.75 the amount of heat as one person so if the client has two servers in a small closet, it can get quite toasty in a very short period of time. If the client has more than three servers in an enclosed room, we should insist on dedicated air conditioning. Even the best extraction fan will move enough air for three servers in an enclosed room.

Please note the word DEDICATED. Typical office air conditioning will turn off over night and on the weekends and will often be programmed to provide heat during the winter. A dedicated zone programmed to always provide cooling is the only way to adequately support servers.

I have an Excel spreadsheet with a heat load calculator that uses the wattage of the power supplies to estimate the BTU usage. That BTU figure can be used by a mechanical engineer or HVAC contractor to design the correctly sized system.

Panasonic produces a line of very efficient, very quiet extractor fans that work well in a typical office environment.

Racks

We should always recommend rack enclosures to clients with more than three servers or clients that are planning growth. The primary benefits are:

Earthquake Protection: Racks can be bolted down or otherwise “corralled” to prevent them from tipping over in an earthquake. It also provides protection from items falling on top of the rack.

• Theft Protection: The majority of theft from offices will be laptops and other items that are easy to grab quickly. Any item screwed into a rack will take several minutes to unscrew and pull out and will definitely limit the chances of someone taking things. Rack enclosures can also be locked.
• Standardized Equipment: There is a wide variety of equipment that is designed to fit into racks which gives you great flexibility in the future
• Ease of Maintenance: A rack or enclosure can have slide out shelves and other equipment that makes routine maintenance easier.

Power

Servers do not consume as much power as they used to but there needs to be some care taken when a client moves into a new space or plans a remodel. All server rooms will require at least one dedicated circuit and perhaps several for larger installations. Actual size of the circuit will depend on the APC UPS you are trying to install. APC’s website has detailed descriptions of the power connections that the APC is expecting. It provides both a NEMA code and a shows a small picture of the exact connection.

Only the APC Smart-UPS 1500 and smaller can use a regular socket. Every UPS larger than that will have some sort of special connection. Make sure that you provide those detailed specifications to the electrician early in the planning process.