Wireles Networking is a practical guide to planning and building low-cost telecommunications infrastructure. See the editorial for more information....

Physical Security

When installing a network, you are building an infrastructure that people will depend on. And thus, the network must be reliable. For many installations, outages often occur due to human tampering, accidental or not. Networks are physical, wires and boxes, things that are easily disturbed. In many installations, people will not know what the equipment is that you have installed, or, curiosity leads them to experiment. They will not realize the importance that a cable goes to a port. People might move an Ethernet cable so that they can connect their laptop for 5 minutes, or move a switch because it is in their way. A plug might be removed from a power bar because someone needs that receptacle. Assuring the physical security of an installation is paramount. Signs and labels will only be useful to few, whom can read, or speak your language. Putting things out of the way, and limiting access is the best means to assure that accidents, or tinkering does not occur.

In less developed economies proper fasteners, ties, or boxes will not be as easy to find. You should be able to find electrical supplies that will work just as well. Custom enclosures are also easy to manufacture and should be considered essential to any installation. It is often economical to pay a mason to make holes and install conduit, where this would be an expensive option in the developed world, this type of labour intensive activity can be affordable in Southern countries. PVC can be embedded in cement walls for passing cable from room to room, this avoids smashing holes every time a cable needs to be passed. To insulate, plastic bags can be stuffed into the conduit around the cables.

Small equipment should be mounted on the wall and larger equipment should be put in a closet or in a cabinet.


Switches, hubs or interior access points can with a wall plug be screwed directly onto a wall. Best to put this equipment as high as possible to reduce the chance that someone will touch the device or its cables.


Cables should be hidden and fastened. Better to bury cables, than to leave them hanging across a yard, where it might be used for drying clothes, or simply snagged by a ladder etc. To avoid vermin and insects find plastic electrical conduit. The marginal expense will be well worth the trouble. The conduit should be buried about 30cm deep (below the frost in cold climates). It is also worth buying larger conduit than is presently required, so that future cables can be run through the same tubing. It is also possible to find plastic cable conduit that can be used in buildings. If not, simple cable attachments, nailed into the wall can be used to secure the cable and to make sure that it doesn't hang where it can be snagged, pinched or cut.


It is best to have power bars locked in a cabinet. If that is not possible, Mount the power bar under a desk, or on the wall and use duct tape (gaffer tape, a strong adhesive tape) to secure the plug into the receptacle. On the UPS and power bar, do not leave empty receptacles, tape them if necessary. People will have the tendency to use the easiest receptacle, so make these critical ones difficult to use. If you do not, you might find a fan or light plugged into your UPS; though it is nice to have light, it is nicer to keep your server running!


Protect your equipment from water and moisture. In all cases make sure that your equipment, including your UPS is at least 30cm from the ground, to avoid flooding. Also try to have a roof over your equipment, so that water and moisture will not fall onto it. In moist climates, it is important that the equipment has proper ventilation to assure that moisture can be exhausted. Small closets need to have ventilation, or moisture and heat can degrade or destroy your gear.


Equipment installed on a mast is often safe from thieves. Nonetheless, to deter thieves and to keep your equipment safe from winds it is good to over-engineer mounts. Equipment should be painted a dull, white or grey colour to reflect the sun and to make it look plain and uninteresting. Panel antennas are much more subtle and less interesting than dishes and thus should be preferred. Any installation on walls, should require a ladder to reach. Try choosing well lit but not prominent places to put equipment. Also avoid antennae that resemble television antennae, as those are items that will attract interest by thieves, where a wifiantenna will be useless to the average thief.

Last Update: 2007-01-24