Internet Fundamentals

Fundamental Terms Underpinning the Internet

07 What is Traffic on the Internet?
A Detailed Explanation of Traffic-Related Issues and Countermeasures

With the spread of video streaming services, remote work, distance learning, and the increasing size of game content, internet traffic is on a continual rise.
Traffic refers to the volume of data flowing through a network. Since communication lines and devices have a limit on the traffic they can handle, traffic control is a crucial topic for businesses involved in IT and communications. Exceeding capacity in traffic directly leads to a decrease in the quality of services provided. This article explains the concept of traffic and measures against its increase in a way that's easy for beginners to understand.

What is Traffic?

Traffic refers to the amount of data flowing through a network within a certain period, similar to the concept of traffic on roads. This data is composed of units called 'packets,' and network communication is conducted through the exchange of these packets.

Troubles Caused by Increased Traffic

As mentioned earlier, when the number of packets exchanged over network lines increases, traffic also increases, leading to network congestion. What problems arise when a network becomes congested? Here, we will explain each specific issue in detail.

Reduction in Network Speed

When traffic exceeds the capacity of network equipment, 'congestion' occurs. Congestion creates a situation where packets cannot be processed correctly, leading to poor data flow and reduced network speeds.

Data Loss

Network devices have a memory area called a 'buffer' for temporarily storing data. When traffic exceeds this buffer's capacity, 'packet loss' occurs, leading to the discarding of incoming packets and potential loss of critical data.
Additionally, in some cases, the sending devices retransmit the discarded data, prolonging the state of congestion due to this cycle of discarding and retransmitting.

Network Downtime

If the above situation worsens, it can lead to network failure. This is a state where servers can stop functioning, and network connections can be completely lost.
When a network failure occurs, connected servers and terminals cannot access network services. This temporarily makes it impossible to browse websites, download files, or communicate online, significantly impacting business and communication.

Measures Against Traffic Increase

To address increased traffic, it's essential to identify the reasons behind it and implement appropriate measures.

Specific strategies include monitoring network traffic and distributing traffic loads.

Monitoring Network Traffic

To understand the causes of congestion, it is important to know where and when traffic increases occur. Therefore, monitoring network traffic is necessary.
By monitoring traffic, abnormal traffic flows or unexpected data increases can be detected early, and measures can be taken before excessive loads are placed on servers and network devices.

Distributing Traffic Load

Traffic load distribution involves evenly spreading traffic across multiple servers or network devices, in an environment with multiple such devices, to prevent excessive load on specific devices. Load distribution can be achieved through the use of load balancers, DNS settings adjustments, and load-balancing software.
This improves network efficiency, promotes system redundancy, and ensures stability.

Types of Network Traffic Monitoring

As mentioned earlier, traffic monitoring plays a role in monitoring traffic information and identifying the causes of problems when they occur.
There are various methods used for this monitoring. Next, we introduce some of the primary methods for traffic monitoring.

SNMP Monitoring

SNMP stands for Simple Network Management Protocol, a protocol for monitoring and controlling the status of devices within a network.

SNMP is a universal standard and can be used with a wide variety of manufacturers and vendors' devices due to its versatility. It is relatively easy to implement as it doesn't require the installation of a specific monitoring tool's agents. However, SNMP is primarily focused on monitoring and management tasks, and more advanced network analysis requires other specialized tools.

Packet Sniffer

A packet sniffer is a method for capturing and monitoring data passing through nodes on a network, providing insight into communication conditions. Nodes here refer to terminals or devices that perform data communication on the network.
Packet sniffers allow for detailed analysis by monitoring the specific contents being sent and received.

While packet sniffers can obtain data at a deeper level than SNMP, the disadvantage is the load they place on the CPU and network.

Flow Monitoring

Flow monitoring is a technology for monitoring traffic flow, i.e., the flow of data on a network, and identifying issues related to network performance. Flow monitoring does not monitor individual packets but monitors information in units called actions, defined over a specific range.
Technologies like Cisco's NetFlow and InMon's sFlow are widely used for flow monitoring. The installation of a system called a flow collector is necessary for collecting and visualizing flow data.
Flow monitoring has the advantage of easily identifying the causes of network problems, but it also has the disadvantage of increasing the load on the CPU and network.

Unlike packet sniffers, which analyze network data at the packet level, flow monitoring is used to understand the overall flow or patterns of a network and is typically more suitable for broader data analysis.


Heavy traffic flow can lead to congestion or server downtime, significantly impacting businesses. When operating a network, it's essential to monitor and manage traffic appropriately to prevent such troubles.