Poorly installed network cabling can cause numerous problems, and even a seemingly minor problem can have severe effects on operations. A kink in a cable can cause a camera to respond intermittently, and a poorly crimped connector may prevent Power over Ethernet (PoE) from functioning correctly.
There are two wiring standards for network cabling: T568a and T568b. It is very important to NOT COMBINE T568a and T568b on the same cable!
Cables are categorized according to the data rates that they can effectively transmit. Cable specifications also describe the material, the connectors and the number of times each pair is twisted per meter. The most widely-installed category is CAT 5e.
- Cat 5e with 100 MHz bandwidth
- Cat 6 up to 250 MHz
- Cat 6A up to 500 MHz
- Cat 7 up to 600 MHZ
- Cat 7A with a frequency range up to 1000 MHz
Video files are generally very large, but still need to be moved around the network as quickly as possible. It is possible to use good quality Cat 5 cabling for gigabit networks, although Cat 5e or Cat 6 is recommended, even if existing network switches and routers only support 100 Mbps. This will ensure that the cabling infrastructure is in place when upgrading to gigabit later.
Use good cable runs
Ensure that your cabling meets the requirements of your equipment. The distance between an Ethernet transmitter and receiver cannot exceed 100 m (325 ft) without being boosted. When installing sockets (outlets), remember to take into account the distance between the socket and the computer. A good rule of thumb is 90 meters for unbroken cable runs, and ten meters for the patch cabling.
Network cabling should NOT be run next to electrical mains cabling, as there is a potential for interference. Nor should network cabling be suspended from ceiling tiles (which may violate building codes and fire regulations).
Using Shielded Twisted Pair (STP) cabling is mandatory when a camera is used outdoors, or where the network cable is routed outdoors. STP cabling must also be grounded - failure to do so can lead to interference. Unshielded Twisted Pair (UTP) cables may be used if there is no risk of interference nearby. For more information about STP versus UTP, see http://www.axis.com/files/whitepaper/wp_network_cables_47113_en_1203_lo.pdf
As network cabling typically uses solid wires, cabling should not be twisted or bent in a tight radius (i.e. less than 4 times the diameter of the cable). Do not use metal staples to secure cable runs, and do not overtighten cable ties.
Keep pairs together and wire correctly
It is very important that no more than about 6 mm of the cable is left untwisted at either end of the cable, or there may be negative impacts on the network. It is essential to wire the plug correctly and to use the correct crimping tool for the specific type of connector.
Environmental considerations will determine the cabling and connectors to use, but also whether or not the camera should be installed in a housing, to protect against acids, severe weather conditions, or extreme heat or cold. See also, Challenge 5, Environmental Considerations.
Certify the installation
In twisted-pair copper wire networks, copper cable certification is achieved through a thorough series of tests in accordance with standards set by the Telecommunications Industry Association (TIA), or the International Organization for Standardization (ISO). These tests are done using a certification testing tool, which provide “Pass” or “Fail” information.