Basic Network Topology

Very simple overview of LAN layouts ....

Network topology refers to the physical layout of a LAN.

I'll introduce 3 popular topologies here:

1. Bus Topology
2. Star topology
3. Extended Star Topology


Bus Topology

Refers to the layout that has all the devices on the LAN attached to a network medium in a linear fashion. The linear medium can be called trunk line, the bus or the highway.
In bus topology every device on the LAN must be indepedantly attached to a common bus wire through a specified connection and the bus wire must be terminated on each end with a terminating resistor or terminator. The terminator absorbs electrical signals so they don't bounce. or reflect back and forth across the bus.
If more than one node on a bus tries to transmit at the same time, collisions occur which result in damaged data; so collision detection must be present on a bus type topology.

Pros and Cons of Bus Topology

Because buses are a very simple wiring layout they are relatively inexpensive in setup costs. Though this can also lead to higher maintenence costs because it tends to be more difficult and time consuming to determine damage areas and isolate the cause and/or source of the problem.


Star Topology

In star topology the network media run from a centralized hub outward to each device in the LAN (like the spokes on a bike). In this type of topology all communication from each device runs through the central hub or link, then the hub directs data to its intended recipient.
An active hub also has the secondary function of a repeater, and a passive hub is merely a messanger between devices.

Pros and Cons of Star Topology

Compared to bus topology stars are rather expensive to setup due to the extra network media that is necessary - but by contrast problems that arise are usually able to be isolated and diagnosed with greater ease and thus, less consumption of time.

With star type topology there are standards that must be followed and I believe that each media running from the centralized hub cannot exceed 100 meters. It also must be noted that signals tend to degenerate when travelling over extended distances and can be too weak to use or completely deteriorated before they reach their destination if the distance is too long and no repeaters are installed .... which brings us to the final topology type I will discuss tonight.


Extended Star Topology

This, in layout is assimilated to star topology, except that in the extended star type the 100 meter standard does not need to be recognized because of the use of repeaters.
Repeaters regenerate and amplify impulses of data that has started to degenerate over the course of its travel and they work in unison with the network media at the physical layer.


That is a basic run down of network topology. I know it is not extensive but network topology is not an extensive subject - networking, yes; topology, no.

Have a good night all and I certainly hope someone learned something here tonight.

Although the guy got negged for plagarism, I'll present this link as a prime example of why you should search the site before posting a tutorial.

http://www.antionline.com/showthread...ght=topologies

To your credit, at least you appear to have done your own work instead of stealing someone else's, and you've stuck to the stuff that's actually getting used out there instead of trying to make everyone learn token ring :P

You know ........... I actually did perform a search before writing this and Im not quite sure what happened - as in I can't remember .......

Sometimes I just lose my train of thought when I have 8 windows (tabs) opened at once and they are all on differant things ........... I guess I just got distracted on something else and eventually closed it down before checking it :rolleyes:

Oh well ........ sorry for wasting bandwidth and all that ...... wasn't my intention ........ Admins - delete this if you feel like it ........ sorry - temporary lapse of reason I guess.