Congestion means while multiple users send data at the same time and the network available is common to them so in this case multiple users send data and their data packets gets collided in that medium and data gets lost in it.

In a congested network, response time slows with reduced network throughput. Congestion occurs when bandwidth is insufficient and network data traffic exceeds capacity.

Typical Causes of Network Congestion

If we does sharing and proceeding of the data in the LAN environment then the chances of congestion gets more because multiple users are sharing the same network and the bandwidth is fixed.

As we add users, proportionally, we're degrading the amount of bandwidth per user. So we're going to get to a certain number of users and it's going to be too much congestion, too many collisions, too many simultaneous conversations trying to occur all at the same time.

And that's going to reduce our performance. Also, when we look at the newer technologies that we're using in our workstations. With early LAN technologies the workstations were relatively limited in terms of the amount of traffic they could dump on the network.

Well, with newer, faster CPUs, faster busses, faster peripherals and so on, it's much easier for a single workstation to fill up a network segment.

Network Traffic Impact from Centralization of Servers

Also, the way the traffic is distributed on our network can have an impact as well. A very common thing to do in many networks is to build what's known as a server farm for example.Well, in a server farm effectively what we're doing is centralizing all of the resources on our network that need to be accessed by all of the workstations in our network.

So what happens here is we cause congestion on those centralized segments within the network. So, when we start doing that, what we're going to do is cause congestion on those centralized or backbone resources.

Servers are gradually moving into a central area (data center) versus being located throughout the company to:

 - Ensure company data integrity
 - Maintain the network and ensure operability
 - Maintain security
 - Perform configuration and administrative functions