Network Hardware (Switches & Routers)
OSI & Hardware
7 Application }Router, Gateway }(Email Gateway)
6 Presentation }Router, Gateway }(Email Gateway)
5 Session }Router, Gateway }(Email Gateway)
4 Transport }Router, Gateway }(Email Gateway)
3 Network }Router, Gateway }(Email Gateway)
2 Data Link(Logical Link Control, Mac) }Network Interface Card - Switch & Bridge
1 Physical }Network Interface Card -Repeater & Hub
1) Repeater & Hub
a. A Repeater is used to extend cable
b. A Hub has the same function as a repeater, but is used with star topology ( Cat 5)
i. *Note~ We have 2 types of repeaters
1. Passive repeater ( Requires no power source)
2. Active repeater, amplifying repeater ( Needs Power Source)
ii. Active Repeaters not only extend cable but also amplify the signal.
a. A bridge layer is a layer 2 device used for connecting two different Net topologies.
i. E.g Laptop >>> Access point – Wireless access point (wireless topology)(>> =
signal) & a star topology on the right side. A bridge is needed in the middle to
connect the two topologies.
ii. A bridge contains a “Database” of all MAC Addresses detected.
iii. A Bridge operates based on an algorithm called “Spanning Tree Protocol”
iv. STP is used to arrange multiple bridges in a parent/child relationship format
v. *~Bridge(root bridge) Bridge(child 1,2,etc)
vi. *~ Note is Root bridge is down, one of the child bridges can claim the role of the
a. A switch has the functionality of a bridge & a hub
b. In contrast to hubs, switches allocate network bandwidth dynamically.
c. In addition to bridging function, a switch can be used to implement virtual Lan
d. A Virtual Lan defines broadcast domain
e. A broadcast domain allows multiple nodes to communicate securely.
Root Switch (Stp) >> Switch (1,2, child switches) (Each switch can represent a division in a company e.g
HR and Sales, also branching out from each of these divisions would contain workstations)
a. *~ Note Only registered members of a Virtual Lan can participate in a two way communication
b. Non-members cannot access Virtual Lan data communication. 4) Network Interface Card: A NIC contains two types of hardware components:
a. Media Access Control
b. Physical Interfa