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.