Quality of Service (QoS) refers to mechanisms used by network devices to prioritize certain types of traffic over others so that latency-sensitive applications like voice, video, or gaming perform better during congestion. Instead of treating all packets equally, QoS can classify traffic and apply policies such as prioritization, bandwidth guarantees, shaping, or rate limiting. However, QoS is extremely loosely standardized—while concepts like DSCP markings and traffic classes exist, how they’re interpreted, enforced, and mapped to queues varies widely between vendors, operating systems, and even individual devices. As a result, QoS behavior is often inconsistent end-to-end, and policies that work on one network may behave differently (or not at all) on another.

Alta Labs provides the following options, ranging from super simple to super granular:

• CAKE (Route10 only)
• Pre-Determined Profiles:
  • Default (No QoS)
    • No predefined DSCP mappings. Only base priority and explicit overrides apply.
  • Enterprise (RFC4594). This profile is a superset of all other profiles, and also includes many industry-standard mappings. If generic QoS is required on a network, this option is typically sufficient to cover all use-cases, including all of the remaining profiles. The advantage of using the remaining profiles is reduced complexity:

• Dante

• Crestron

• Q-SYS

• SHURE

• AES67

• VoIP

• DSCP Value Prioritization
• TOS Value Prioritization
• Dynamic Prioritization
• Color Code Integration for Rapid Deployment

Setting Up QoS - Basic

1. From the Network tab, click the icon of a Switch or the Route10
2. Click the interface you want to set QoS for
3. Scroll down to QoS Profile
4. Select your desired profile
5. Optionally, specify a QoS Priority
   1. The QoS Priority field is a baseline. If the traffic doesn’t match any other rule specified for QoS, the traffic will be subjected to the priority specified here.
6. Click Save

Setting Up QoS - Advanced

1. From the Network tab, click the icon of a Switch or the Route10
2. Click the interface you want to set QoS for
3. Scroll down to QoS Profile
4. Set the Profile to anything but “Default”
   1. Note that you have new fields
5. QoS Priority (0-7)
   1. The QoS Priority field is a baseline. If the traffic doesn’t match any other rule specified for QoS, the traffic will be subjected to the priority specified here. This can be overridden in the following step
6. DSCP/TOS Selectors
   1. DSCP values allow for 0-63
   2. TOS values allow for 0-255
7. Click the + Icon to add more selectors
8. Save

Scaled Deployment Using Color Codes

Let’s say you have a large number of devices and need to apply QoS rules without the tedium of setting QoS on every single interface. No worries! Alta has your back with color codes.

1. From the Network tab, click the icon of a Switch or the Route10
2. Click any interface you want to set QoS for OR any unused interface
3. Select a color group (Note that Black cannot be edited)
4. Click the Pencil icon next to your chosen color group
5. Scroll down to QoS Profile
6. QoS Priority (0-7)
   1. Consider this as an all encompassing “all traffic through this port will be affected”, then we can override certain traffic in the next steps
7. DSCP/TOS Selectors
   1. DSCP values allow for 0-63
   2. TOS values allow for 0-255
8. Save
9. Use the Select option to deploy the color code to multiple interfaces
10. Select your color selected in Step 3

Dynamic Priority vs. Static Priority

Consider the following settings. For this section, we're going to use an example of Increasing the priority for VoIP via DSCP and Infrastructure traffic via TOS using the appropriate values from the tables below.

The relevant fields here are the QoS Priority, DSCP row, and the ToS row. You'll notice that the priority of 6 is set for DSCP value 46 (VoIP) and +7 for TOS 56. With this configuration:

• Network control, routing protocols, infrastructure traffic takes the highest priority (dynamic value of 7)
• VoIP takes the next priority (static value of 6)
• All other traffic gets next and final priority (QoS Priority of 0)

The +# means "add # to the QoS Priority, in this example, 0+7 = 7

Now consider nearly an identical configuration:

The only change relative to the last screenshot is QoS Priority is now 4.

What changes in terms of actual, real-world results? Nothing, actually.

• QoS Priority is 4
• DSCP 46 is a static value still, at 6
• TOS 56 is still dynamic and +7. So 4 + 7 = 11, right? Not quite, since the highest priority is 7, therefore 4 + 7 = 11, but 11 is higher than 7, so the firmware automatically says 11 > 7, priority = 7
   

DSCP Values

Think of DSCP as “Type of traffic”, the table below outlines these types and what they mean

Note: The DSCP to Priority (0-7) mapping in the table above is a general guideline based on industry best practices and the context of the provided Alta Labs profiles (e.g., Enterprise profile often maps 48/56 to Prio 7, 46 to Prio 6, etc.). Actual mapping within Alta Labs devices is determined by the selected QoS Profile or explicit port overrides.
 

ToS Values

DSCP Values are a subset of the IP ToS field. DSCP values have more commonly been used, historically, but Alta switches are also capable of mapping from ToS values to raw priority, as well. The following table gives an example of common equivalent mappings between some DSCP values and ToS values.