Chapter 3 93-107 Flashcards
how do you decide what networking media to use?
match needs with characteristics of the media
what are the limits of throughput?
cannot travel faster than light (fiber optic cable), reduced by noise, reduced by multiplexing technique
Why is the cost of cables not the only thing to consider?
you might have to upgrade hardware to meet the cable needs
what is the time frame for cable installations?
you should plan for 10 years of future use needs.
What can help to protect from noise?
you can enclose your cables in a conduit pipeline that insulates them
What is a populated segment?
a segment of cable that has end nodes, ie a switch that connects users in a classroom is part of a populated segment
what is an unpopulated segment?
a part of a network that does not contain end nodes, can be called a link segment, ie: connects two routers together
Why are segment lengths limited?
after certain lengths the signal becomes too weak = data loss
what is coaxial cable?
the kind used for tv with the copper wire in the center.
what type is found nowadays?
RG – 6 (which has 75ohms)
what is twisted pair cable?
colour coded pairs of insulated copper wires .4-.8mm
how do you prevent crosstalk in twisted pair cable.
the more twists per food, the less cross talk… twist ratio
what is the problem with high twist ratio?
greater attenuation (weakening signal)
What category do modern wans use?
Cat 6 wires
How many wires are inside typical cables?
4 wire pairs, one for sending and one pair for receiving
What is STP cable?
Shielded twisted pair
Why shield cables?
the shielding acts as a barrier for electromagnetic forces, so signal is not affected
What is UTP ?
unshielded twisted pair cable
what is the problem with UTP
it is just contained in a plastic wire case, so is cheaper but has more noise affect
what are cat 5 specifications
1000 Mbps throughput, 100 MHz signal rate
how is cat 6 different than cat 5 wire?
the wire is shielded with foil insulation to prevent crosstalk, 250 MHz and 6x cat 5 throughput
