3 Priority Queues Explained

1. Understanding Priority Queues

Priority Queues are a feature in MikroTik RouterOS that allows you to prioritize different types of network traffic. This ensures that critical applications receive the necessary bandwidth, while less important traffic is managed accordingly. Priority Queues are particularly useful in environments where multiple types of traffic need to be managed efficiently.

2. Key Concepts

There are three primary concepts to understand when configuring Priority Queues in MikroTik:

a. Queue Types

Queue types define how traffic is prioritized and managed. Common queue types include:

• Simple Queue: Manages traffic based on a single rate limit.
• FIFO (First In, First Out): Processes packets in the order they are received.
• Priority Queue: Assigns different priorities to different types of traffic.

b. Packet Marking

Packet marking involves tagging packets with specific DSCP (Differentiated Services Code Point) values. These tags are used to prioritize traffic based on its importance. For example, VoIP traffic might be marked with a high DSCP value to ensure it receives priority over other types of traffic.

c. Class-Based Queuing

Class-Based Queuing allows you to create different classes of traffic and apply specific rules to each class. This provides granular control over how different types of traffic are managed. For example, you can create a class for VoIP traffic, another for web browsing, and a third for file transfers, each with its own priority and rate limit.

3. Detailed Explanation of Key Concepts

a. Queue Types

Queue types determine how traffic is processed. Simple Queue is straightforward, managing traffic based on a single rate limit. FIFO processes packets in the order they are received, ensuring fairness but not prioritization. Priority Queue, on the other hand, allows you to assign different priorities to different types of traffic, ensuring that critical applications receive the necessary bandwidth.

b. Packet Marking

Packet marking is crucial for prioritizing traffic. By tagging packets with DSCP values, you can ensure that critical applications like VoIP receive priority. For example, marking VoIP packets with a high DSCP value ensures that they are processed ahead of other types of traffic, reducing latency and ensuring clear voice communication.

c. Class-Based Queuing

Class-Based Queuing provides granular control over traffic management. By creating different classes for different types of traffic, you can apply specific rules to each class. For example, you can create a high-priority class for VoIP traffic, a medium-priority class for web browsing, and a low-priority class for file transfers. This ensures that each type of traffic is managed appropriately, optimizing network performance.

4. Practical Examples and Analogies

Example 1: Prioritizing VoIP Traffic

In a corporate environment, VoIP traffic needs to be prioritized to ensure clear voice communication. By creating a Priority Queue and marking VoIP packets with a high DSCP value, you can ensure that VoIP traffic receives priority over other types of traffic, reducing latency and improving call quality.

Example 2: Managing Web and File Traffic

In a home network, web browsing and file transfers need to be managed efficiently. By creating a Class-Based Queue, you can assign a higher priority to web browsing traffic and a lower priority to file transfers. This ensures that web pages load quickly while file transfers are managed without disrupting other activities.

Analogies

Think of Priority Queues as lanes on a highway. High-priority traffic (like emergency vehicles) is given a dedicated lane to ensure it moves quickly, while other traffic is managed in other lanes. Packet marking is like assigning a special sticker to high-priority vehicles, ensuring they are directed to the correct lane. Class-Based Queuing is like creating different lanes for different types of traffic, ensuring that each type of traffic is managed appropriately.

By mastering Priority Queues in MikroTik, you can create a network that is both efficient and reliable, providing a smooth user experience even under heavy load. This knowledge is essential for anyone aiming to become a MikroTik Certified Routing Engineer.