Lecture 1(b): Networking Basics

Parts Of Networks:

e.g Channels are also referred as Media.We will Discuss it Further.

Network Topologies:

•Network topology defines the structure of the network.

•One part of the topology definition is the physical topology, which is the actual layout of the wire or media.

•The other part is the logical topology, which defines how the media is accessed by the hosts for sending data.

Physical Topologies:

 Normally in Network Star topology is used.

Logical Topology:

 

•The logical topology of a network is how the hosts communicate across the medium.

•The two most common types of logical topologies are broadcast and token passing.

Logical Topologies
Broadcast:

•Broadcast topology simply means that each host sends its data to all other hosts on the network medium.

•There is no order that the stations must follow to use the network.

•It is first come, first serve.Ethernet works this way.

Logical Topologies
Token Passing:

•Token passing controls network access by passing an electronic token sequentially to each host.

•When a host receives the token, that host can send data on the network.

•If the host has no data to send, it passes the token to the next host and the process repeats itself.

•Two examples of networks that use token passing are Token Ring and FDDI(Fiber Distributed Data Interface)