With the rapid development of the internet, various network-based attacks and viruses have also increased, and similar issues are often encountered within internal networks. This necessitates a security mechanism to protect the normal operation of the network, which led to the birth of the router’s QoS feature. QoS is a technology used to solve problems such as bandwidth, network latency, and congestion. It typically includes priority levels, flexible bandwidth management, and more.
I. First, let’s introduce some basic concepts of QoS to help you understand it better:
1. Small Packet Priority: Small packets usually refer to packets smaller than 64K, such as ping packets, request packets, and response packets. During internet browsing, many requests and responses occur. Prioritizing these packets makes our browsing experience feel much faster.
2. IP/Network Segment Priority: Priority levels can be set based on source IP, destination IP, or network segments. For example, within a local area network, I can guarantee my web server’s bandwidth first, then the client machines’ bandwidth, and then the server’s bandwidth. All of these can be configured.
3. Port Priority: Priority levels can be set for source ports and destination ports. Generally speaking, in internet cafes, gaming is the main activity. So, I can prioritize the bandwidth for certain mainstream game ports.
4. Surplus Bandwidth Preemption Priority: As the name implies, during usage, when network bandwidth has surplus, this remaining bandwidth can be allocated to certain IPs or ports. This allows you to fully utilize the bandwidth without wasting it!
II. Flexible Bandwidth Management, taking download speed limiting as an example: Assume total bandwidth is 10 Mbit, shared by 20 people, with a guaranteed download speed of 100 KBytes/s and a maximum download speed of 200 KBytes/s. The configuration is as follows:
1. When bandwidth is idle, the speed can reach the maximum speed. If bandwidth is idle, the download speed can reach up to 200K. 200K is the peak download speed, and even if only one person is using the bandwidth, it will not exceed this peak speed. 100K of this 200K is temporarily borrowed from others, and it will be automatically relinquished when others need it.
2. When bandwidth has a certain usage rate, the speed falls between the “guaranteed speed” and the “maximum speed.” If bandwidth has a certain usage rate (with a certain number of people online, bandwidth usage is around 80%, e.g., 15 people online), the download speed will drop to between the “guaranteed download speed” and the “maximum download speed,” i.e., 100K ~ 200K.