N ETWORKING C OMPONENTS A-3 LTEC 4550 by Joe Garcia

H UB Description A small (layer 1) device that joins multiple computers or devices together to form a single network or segment on a LAN. Broadcast layer 2 packets with optional amplification (dumb switch). Type of hubs include passive, active and intelligent. Cost Small USB hubs $20-$40.

S WITCH Description A switch connects multiple devices and segments on a LAN with better management tools than a Hub. Similar to a hub except with more intelligence and operates at layer 2 or 3 for rapid and efficient packet routing. Provides network segment creation and control to limit access to various parts of the network. Cost Mini 8 port Gigabit switches $20-$60. Business class switches $400-$3500 (depending on configuration).

R OUTER Description Provides connections to offsite networks (WANs) such as Internet or other remote site. Provides traffic filtering, bandwidth management and failure link failure re-route. Operates at Layer 3, have their own OS and support several WAN protocols such as ISDN, Frame Relay, and ATM. Cost Business class routers $500-$5000 (depending on configuration).

B RIDGE Description Filters data traffic on the LAN at Layer 2 reducing the amount of traffic, reducing collisions. Inspect each MAC address and decide to forward or discard it, including source and destination for individual forwarding decisions. Connects multiple LAN segment to each other. Cost Business class bridges $400-$3500 (depending on configuration).

G ATEWAY Description A network gateway’s main purpose is to join networks that use different base protocols and can be implemented by strictly software or hardware. Some example gateways can be VoIP gateways, or even DSL to Ethernet gateways such as those at your home. Cost $100-$20,500 (depending on configuration).

F IREWALL Description Provides network protection from intentional intrusion, can be either hardware or software based. Operates at Layer 3 and up of the OSI model. Inspects packets and allows or blocks packets based on set rules creating a choke point of control and monitoring. Some features include: port control, network address translation, application monitoring, packet filtering, data encryption, protection, pop-up blocking, cookie digestion and spyware protection. Cost Software firewall $40-$75, hardware $600-$17,000 Software Hardware

W IRELESS A CCESS P OINT (WAP) Description Acts as a transmitter/receiver for wireless radio signals such as Wi- Fi to provide access to the Internet. Provides infrastructure connection between the wireless local network and the wired Ethernet network. Provides Internet connectivity using external or built-in DSL, cable or cellular uplink capabilities. Cost $150-$2500 (depending on configuration).

T OTAL N ETWORK D IAGRAM