1. What is Network?
A computer network allows sharing of resources and information among interconnected devices.
[ Node - End System ]
[ Inter Media - such as Router ]
2. Network Topology
a. Bus Topology
Disadvantage
- If the network cable breaks even if one, the entire network will be down.
- A terminator is required at each end of the bus cable to prevent the signal from bouncing back and forth on the bus cable.
[ Line - Media - 매체 ]
b. Star Topology
The primary disadvantage of the star topology is that the hub represents a single point of failure.
중앙집중식
c. Ring Topology
The primary disadvantage of ring topology is the failure of one machine will cause the entire network to fail.
단방향성이다. Token을 이용하여 통신한다.
Ring topologies typically utilize a token passing scheme, used to control access to the network.
d. Mesh Topology
1:n form
The number of connections in a full mesh = n(n - 1) / 2
high cost, high reliability
3. Scale of Network
Common types of computer networks may be identified by their scale.
LAN - Local Area Network
WAN - Wide Area Network
MAN - Metropolitan Area Network
PAN - Private Area Network
VAN - Valuable Area Network
4. Ethernet
Form of Logically Bus Topology or Physically Star Topology
Medias
In the Past
RG-58U, RG-58A/U, RG-59 -> Coaxial Cable
RG - 59 image
these days
UTP(Unshielded twisted pair )
STP(Shielded twisted pair )
UTP image
STP image
Categories
Category 5
Category 6
[ Hub - 전기 전달, 증폭 기능을 한다. 전기를 제어하지는 못한다. ]
UTP Cabling
568A, 568B
straight-through Cable = 568A<->568A, 568B<->568B
Cross-Over Cable = 568A<->568B
ㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡ Straight-through
ㅡ ㅡ ㅡ ㅡ ㅡ ㅡ ㅡ ㅡ ㅡ ㅡ ㅡ ㅡ ㅡ ㅡ ㅡ Cross-Over
