In an age where all of us rely on our broadband service for work, health, and entertainment applications, Quality of Service (QoS) differentiation is a well-developed concept for guaranteeing the quality of different applications and balancing them within the limitations of our home networks and WAN connections. Differentiated Services Code Point (DSCP) marking is one solution that serves as an essential tool for implementing QoS policies in broadband Customer Premises Equipment (CPE) and Wi-Fi routers.
For manufacturers of these devices, ensuring that DSCP based QoS works, and works well, when prioritizing video, voice, and other data is crucial to ensuring a quality end-user experience. Here’s a bit about DSCP and how you can test it on your products using CDRouter.
DSCP marking is a mechanism employed in the Differentiated Services (DiffServ) architecture to classify and prioritize network traffic. It involves assigning a specific value to the DSCP field in the IP header of a packet. This value determines how the router should treat this packet in relation to other traffic it is handling, balanced with available resources.
The DSCP field is incredibly flexible in the use of its value, so traffic classes (voice, video, best-effort, and bulk) are made to help categorize the use of it. The appropriate algorithms (Active Queue Management, or AQM) are further specified by various versions of the DiffServ definition, most recently DiffServ4. These algorithms are designed to mitigate several different causes of packet loss and poor latency, such as Bufferbloat.
Broadband gateways and Wi-Fi routers are typically responsible for handling a wide range of applications with varying QoS requirements. Especially today, many of these services have become mission-critical to broadband users such as telehealth, education, and remote working.
DSCP marking allows these devices to prioritize time-sensitive and mission-critical applications, such as Voice over IP (VoIP) and video conferencing, over less critical traffic like file downloads or software updates. It allows these devices to manage traffic more effectively, reducing latency, jitter, and packet loss. This leads to improved performance for applications like online gaming, video streaming, and real-time communications.
The validity of your device’s implementation of DSCP marking is difficult to prove with manual testing. To accomplish it, you’d need to do the following:
Each of these steps must be done in a consistent and repeatable manner over the course of multiple test runs.
CDRouter’s Performance Expansion includes automated test cases designed to do this fairly easily by configuring the test environment, sending data with the right traffic classes, and delivering clear pass/fail results. In these tests, CDRouter takes the following steps:
Ensuring that a device correctly prioritizes different types of traffic according to their DSCP markings will enable the device to perform better and use fewer resources. Providers can offer superior per-application services to their users, effectively manage traffic loads, and reduce the risk of issues such as bufferbloat. The CDRouter DSCP modules provide a comprehensive environment to test and validate the QoS implementation in a broadband CPE or Wi-Fi router. You can learn more about how it all works in our Performance User Guide!