Cabling FAQ's

1. Q: Do you offer bulk rate pricing for larger jobs?
   A: Yes.

2. Q: What is a Plenum ceiling?
   A: According to the National Electric Code (NEC) a plenum is a "compartment or chamber to which one or more air ducts are connected and [which] forms part of the air distribution system." In other words, the open space above your ceiling extends above other rooms in the same building or is open to ducts that connect it to other parts of the building. In a plenum ceiling air can circulate through the air ducts to the whole building.

3. Q: If I have a Plenum ceiling how does that affect my cabling needs? (What is the difference between PVC and Plenum rated Cable.)
   A: PVC Cable is the most common type of cable used today and consists of a chemical compound called Poly Vinyl Chloride. If a fire occurs, burning PVC Cable can emit large quantities of dense black toxic smoke, and significant amounts of hydrochloric acid. If you have a Plenum ceiling, having PVC cable in the ceiling during a fire would cause a concentration of these fumes to be spread throughout the building. Exposure to these fumes could then hinder the safe evacuation of persons in the vicinity and result in increased fatalities. Plenum Rated Cable has a special coating on the wire, which causes it to burn at a much higher temperature and emit fewer fumes than conventional PVC. As a result, the National Electric Code (NEC) requires that only plenum rated cables be installed in plenum air spaces.

   The chief difference when planning cabling for a facility with a plenum ceiling is to know that plenum Cable is more expensive than PVC so make sure when you're getting estimates that they are all for plenum cable.

4. Q: If I don't have a Plenum Ceiling can I/should I have Plenum Cable installed anyway?
   A: You most certainly can have plenum installed if you wish. The NEC does not require it though, so the decision is really up to you. Just remember that Plenum is more costly to install than PVC.

5. Q: What is the difference between Cat3, Cat5, Cat5e, Cat6, etc.?
   A: This is actually a somewhat complex question to answer as it involves a number of technical details. The most basic answer is that each Category of cable is supposed to meet (or exceed) a specific set of standards, the most significant of which, is the ability to pass all signals up to a particular carrier frequency (or signaling rate). Additional standards have to be met include values for attenuation, near end cross talk (NEXT), ACR, etc.

   Below is a table of the types of Category Cable we install. The table shows the Maximum Carrier Frequencies required by the EIA/TIA 568 Standards for each category of cable and the Maximum Frequencies the manufacturer actually tests the cable to.

   Category	Typical Applications	Frequency Required	Tested to	EIA/TIA Ratified Standard?
   Cat 3	Voice	16 MHz	16 MHz	Yes
   Cat 5	Voice, Data (10/100 Mbps Ethernet)	100 MHz	100 MHz	Yes
   Cat 5e	Voice, Data (10/100 Mbps/ Gigabit Ethernet)	100 MHz	200 MHz	Yes
   Cat 5 ENH1	Voice, Data (10/100 Mbps/ Gigabit Ethernet)	*	350 MHz	See note 1.
   Cat 6	Voice, Data (10/100 Mbps/ Gigabit Ethernet)	200 MHz	500 MHz	Yes

   ¹ Cat 5 ENH is another version of Cat 5e offered by the manufacturer we use that further exceeds the Cat 5e EIA/TIA Standard.
   

6. Q: What do you recommend we have installed for use in our Ethernet network?
   A: In most circumstances we currently recommend Cat 5e. The 5e product we use has been tested by the manufacturer to the the 200Mhz level which will leave adequate bandwidth for current and future applications while helping to keep installation costs down. However if cost is less of an issue and you're seriously concerned with higher data rates for future applications then we would recommend Cat 6.

7. Q: Can Cat 5e/Cat 6 work with our existing Cat 5 patch panel?
   A: Yes, BUT if different category components, such as a patch panel or a jack are used with a higher category component such as a higher level of cable then your data lines will only perform to the level of the lower category device. So if you used Cat 6 cable with a Cat 5 patch panel you should only expect to get Cat 5 performance. For optimum performance ALL components (data cable, patch panel, jack, and patch cables) must be of the same Category level.

8. Q: I have offices that are a good distance from the telco closet, what is the maximum length a Category 5/5e/6 cable can be and still work?
   A: According to the EIA/TIA-568 standards the end-to-end connection between network devices should not exceed 100 meters (328 feet). Note that 100 meters is total length including all patch cables. Officially no one single line from a patch panel to the outlet in the work area should exceed 90 meters (294 feet) so that you have length to spare (10 meters) for the patch cables running from the outlet to your computer and from the patch panel to your switch or hub.

9. Q: I need both voice and data cable installed; is there any advantage to installing Cat 5e or Cat 6 for my phone system?
   A: Having Cat 5e or 6 installed for both your data and phones offers you the flexibility to use your phone jacks as network jacks in the future (assuming you have the cables terminated onto a patch panel). If you use Cat 3 for your phones then your future use of those cables will be pretty much limited to that purpose. Note that while the price differential between Cat 3 and Cat 5e/6 is getting slimmer the one disadvantage is still that a Cat 5e or 6 installation will still be more expensive.