Cat 5, ( cat5e ) short for Category 5, is the current preferred industry
standard for network and telephone wiring. Cat 5 is an unshielded twisted
pair type cable exclusively designed for high signal integrity. The cable
consists of four pairs of 24-guage twisted copper pairs terminating in an
RJ-45 jack. If a wire is certified as Category 5 and not just twisted pair
wire, then it will have "Cat 5" printed on the shielding.
The actual Cat 5 standard describes specific electrical properties of the
wire, but Cat 5 is most widely known as being rated for its Ethernet
capability of 100 Mbit/s. Category 5 cable comes with three twists per inch
of each twisted pair of 24 gauge copper wires within the cable. The twisting
of the cable helps to decrease electrical interference and crosstalk. Each
wire in a Cat 5 cable is insulated with a plastic (FEP) which has low
dispersion. The importance of this insulation is that the dielectric
constant of the plastic does not depend mainly on frequency.
Because most people already have a broadband (high speed) internet
connection already, VoIP voice over IP phones can turn this connection into
a way to place free phone calls. The practical upshot of this is that by
using some of the free VoIP software that is available to make Internet
phone calls, you are bypassing the phone company (and its charges) entirely.
VoIP is a revolutionary technology that has the potential to completely
rework the world's phone systems. You may well have heard or even be using
the skype system. This uses your computer as the intelligence that converts
your speech into voip packets. It means that if you buy a cheap (£10-£20)
USB handset you can “call” via the computer someone else anywhere in the
world that has similar equipment. This is great news for families and
friends that end up all over the country or world, but what if you need to
speak to them when they are away from their computers ie business users.