Cat 5e vs. Cat 6 for IP Cameras?By: Ethan Ace, Published on Jan 30, 2012
What cabling should you use for IP cameras? Cat 5e or Cat6? Spend any time talking to cabling professionals these days, and they'll tell you that Category 6 cabling is the only way to go in any new application. However, Cat 6's increased performance comes at an increased cost over Cat 5e. In this update, we'll look at how the two compare, specific performance issues which may be of interest to installers, and whether Cat 6 is really needed in surveillance applications.
Cat 5e and Cat 6 are the two main UTP cables in use today. Both have similar construction, made up of four twisted pairs of copper wire in the range of 22-24 AWG under a single jacket. They do have some key differences, however:
- Cat 5e: Cat 5e is rated to a max operating frequency of 100 MHz. It's main use historically has been for Fast Ethernet (100Base-T), but it's capable of gigabit speeds using all four pairs, as well. Cat 5e uses 24AWG conductors, with few exceptions. The following image shows a partially stripped Cat 5e cable:
- Cat 6: Cat 6 is rated to a max operating frequency of 250 MHz. A variant of gigabit Ethernet was created to take advantage of its better performance characteristics to use only two pairs for gigabit speeds. However, most gigabit transmission still uses four pairs today. Cat 6 often uses 23 AWG conductors, which makes it less flexible and gives it a larger outside diameter, requiring more care in installation. Cat 6 cables also commonly use a physical barrier in the cable to maintain separate between pairs. The following image shows a stripped Cat 6 cable. The white separator can be seen in the middle of the pairs:
- Cat 6A: While Cat 6A is intended for high-speed applications, far removed from surveillance, it should be mentioned for completeness. Cat 6A uses conductors of up to 22 AWG, and is rated up to 500 MHz. It is finding use mostly in data center applications, as it's capable of up to 10-gigabit Ethernet.
Aside from these physical characteristics, there are a slew of other parameters which these cables are tested for, such as crosstalk (interference between conductors), attenuation (signal loss due to distance), and return loss (loss of signal power due to reflected signal). Cat 6 and Cat 6A also are tested for parameters Cat 5e is not, essentially for better interference rejection. These factors, combined with increased bandwidth, are what allow higher-rated cables to perform better.
Do I Need Cat 6?
Based on the above information, the question then becomes whether surveillance applications need this extra performance provided by Cat 6? The honest answer is: No. Very, very few IP cameras use gigabit Ethernet connections, and Cat 5e is easily capable of 100 Mb Ethernet.
Where Cat 6 does have potential, however, is in locations which may be more difficult environments. These include "noisy" facilities with a lot of RF or electromagnetic interference, which may create transmission errors. High temperatures also negatively impact cable performance, as throughput decreases as temperature increases. Finally, if a large quantity (100+) of cables are to be installed in the same path, such as cable tray, signal coupling can occur.
Cat 6's superior performance allows it to reject interference from these outside sources better than Cat 5e. Additionally, it simply allows for more headroom due to increased bandwidth. This means that while its performance may be decreasing due to any of the above factors, it has a better chance of maintaining a usable level of performance where Cat 5e could not. Substantially decreased performance can lead to blocking and ghosting in video, or just plain video loss.
Cat 5e and Cat 6 cables compare as follows:
- Cat 5e Non-plenum : $0.15-0.20 USD
- Cat 5e Plenum: $0.25-0.30
- Cat 6 Non-plenum: $0.20-0.25
- Cat 6 Plenum: $0.35-0.40
Jacks and patch panels also see an increase in price:
- Cat 5e Jack: ~$3.00 online [link no longer available]
- Cat 5e 24-port Patch Panel: ~$100 online
- Cat 6 Jack: ~$6.00 online [link no longer available]
- Cat 6 24-port Patch Panel: ~$150 online
If you take these figures and apply them to a typical camera, with a 150' cable run, it adds up to about $20 more in material per camera, not a trivial amount, but not necessarily cost-prohibitive. In projects where budget is a vital concern, it may add up, however. Users should be aware of customer IT department requirements, as well, as many organizations have standardized on Cat 6 for all installations.