Netgear CG814WG 사용자 설명서

Networks, Routing, and Firewall Basics

D-11

Unlike simple Internet sharing routers, a firewall uses a process called stateful packet inspection to 
ensure secure firewall filtering to protect your network from attacks and intrusions. Since 
user-level applications such as FTP and Web browsers can create complex patterns of network 
traffic, it is necessary for the firewall to analyze groups of network connection “states.” Using 
Stateful Packet Inspection, an incoming packet is intercepted at the network layer and then 
analyzed for state-related information associated with all network connections. A central cache 
within the firewall keeps track of the state information associated with all network connections. 
All traffic passing through the firewall is analyzed against the state of these connections in order to 
determine whether or not it will be allowed to pass through or rejected.

Although Ethernet networks originally used thick or thin coaxial cable, most installations currently 
use unshielded twisted pair (UTP) cabling. The UTP cable contains eight conductors, arranged in 
four twisted pairs, and terminated with an RJ45 type connector. A normal "straight-through" UTP 
Ethernet cable follows the EIA568B standard wiring as described in 

In the wiring table, the concept of transmit and receive are from the perspective of the PC. For 
example, the PC transmits on pins 1 and 2. At the hub, the perspective is reversed, and the hub 
receives on pins 1 and 2. When connecting a PC to a PC, or a hub port to another hub port, the 

1

Orange/White

Transmit (Tx) +

2

Orange

Transmit (Tx) -

3

Green/White

Receive (Rx) +

4

Blue

5

Blue/White

6

Green

Receive (Rx) -

7

Brown/White

8

Brown