VI. Feature Setup

Prioritise Applications & Services easily with App QoS on a DrayTek router

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App QoS
Application-based QoS
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DrayTek's Quality of Service can help to make the most of an Internet connection. It does so by splitting up the connection into multiple Queues of different levels of importance and time-sensitivity.

Each of the QoS Class groups (Class 1, 2, 3) is assigned priority in order, with Class 1 (and Auto-VoIP) being the highest priority, then Class 2, Class 3 and then Others. Each Class group can have bandwidth reserved for it, ensuring each Class always has sufficient bandwidth available to give the best performance to all services. 'Others' traffic is the default queue, which can be thought of as being processed on the best effort basis and is unhindered if there isn't any traffic in higher priority classes. Any unused reservation from Class 1,2,3 can be used by the Others class.

Setting up Quality of Service is simplified by App QoS, by selecting which Applications & services to prioritise, without needing to configure QoS Classes and Rules extensively. App QoS is also great for applying QoS to types of traffic that can otherwise be difficult to identify.

Setup of App QoS just requires a few steps:

1 Configure App QoS Select which Applications to prioritise from a list, then set which level of priority. Traceable Apps/Protocols have individual QoS priorities. Untraceable Apps/Protocols can be set as a group
2 Enable & Tune QoS Activate Quality of Service for a WAN interface and ensure it's properly tuned to give the best performance
3 View QoS Statistics Check the activity of Quality of Service in real time

Step 1 - Configure App QoS

App QoS can be very useful to prioritise some services over others. When QoS is enabled on the router, anything not assigned to a Class 1, 2 or 3 QoS Rule is put into the "Others" (Lowest Priority) queue.

App QoS makes it much easier to lift up the priority of specific applications and services. That means instead of manually setting every App / Service to Class 3 / Others queue, App QoS can work best when setting important App traffic into Class 1 or Class 2.

Application-based Quality of Service classifies traffic in two ways, Traceable and Untraceable. Traceable services are lower level, while Untraceable services are usually applications built on top of lower level Internet services. There are some differences in how they're applied on the router:


  • Communicate with clearly defined Internet protocols that can be easily determined through packet inspection.
  • May be operating on non-standard ports but the router can identify the traffic from how a session is initially set up.
  • Can have priority settings configured for individual protocols.
  • Useful for prioritising services without needing to configure QoS Rules & Service Types.
  • Enabling some Traceable services such as "SSL / TLS" or "QUIC" could include a lot of Internet traffic, so apply settings here carefully.


  • The router identifies these through packet inspection, it determines what's what by identifying packet sequences unique to these applications.
  • Communicate over the Internet using standard protocols.
  • Priority settings for Untraceable Apps are set for the whole group.
  • Useful for prioritising services that are otherwise difficult to define with QoS Rules & QoS Service Types.

Here are some examples of the types of traffic that App QoS can prioritise:

Domain Lookup DNS IM - Instant Messaging Facebook
Email    IMAP Google Hangouts
POP3 iMessage
SMTP WhatsApp
Network Console & Chat   IRC Spotify
TELNET PROTOCOL - Network Protocols SQL - Database traffic
SSH SIP/RTP - Low Level VoIP
SNMP TUNNEL - Tunnelling & VPN  DNSCrypt
File Sharing SMB - Windows Networking LogMeIn Hamachi
NNTP - Newsgroups ZenMate
FTP - File Transfer Protocol Tor
Internet Access SSL/TLS - HTTPS STREAM - Streaming Video Services YouTube
HTTP REMOTE CONTROL - Remote Desktop  Ammyy Admin
QUIC TeamViewer
           Windows RDP
WEB HD - Cloud Storage Services   Dropbox
Microsoft OneDrive
Google Services

Configure App QoS - Initial Setup

Access the router's web interface and in the top left corner, set the Auto Logout setting to "Off" while setting this up. It can take a few minutes to decide which applications to prioritise and this avoids those settings being lost if they're not saved in time:

To configure App QoS, go to [Bandwidth Management] > [App QoS], select the Enable radio button and click OK to save that setting. Nothing is enabled yet, so App QoS won't do anything.

Configure App QoS - Traceable Services

On the Traceable tab, pick out some services that might be beneficial to prioritise, for instance DNS is safe to prioritise and setting it to Class 1 (Highest) can speed up the responsiveness of Internet access.

Enabling App QoS for very common services like "SSL/TLS" (HTTPS web traffic) and "QUIC" (Google Chrome web traffic) and setting a high priority could have a negative effect on connectivity. It's often best to leave bulk traffic, like regular HTTPS (SSL/TLS) and QUIC un-prioritised.

Click OK to save and apply those App QoS settings.

Configure App QoS - Untraceable Services

On the Untraceable tab, set the Action as the priority level for all of the services enabled on this tab. Anything not classified by these App QoS settings or other QoS rules is in "QoS Other (Lowest)".

In this example, the services here will be classified as "QoS Class 2 (Medium)" so that they're given higher priority. This allows these applications to be prioritised over regular bulk traffic, which can be great for remote desktop and messaging services. Putting them into QoS Class 2 leaves room for high priority services like VoIP if they're set up in other QoS Class Rules.

Scroll through the list, selecting any services that can benefit from being prioritised as this group. Click OK when done to save and apply the App QoS configuration.

Step 2 - Enabling and Tuning Quality of Service

Once App QoS has been configured, go to [Bandwidth Management] > [Quality of Service].

Tick the Enable checkbox for each WAN interface that you want to apply Quality of Service to, then configure the speed and bandwidth reservation values:

WAN TypeInbound / Outbound BandwidthClass 1 / 2 / 3 / Others Bandwidth Reservation %
WAN1 on DSL Routers xDSL routers determine the correct speed to use from the DSL sync rate

Consider the amount of bandwidth that each Class might potentially require and set the reservation % accordingly.
Class 1 can use bandwidth from Class 2, 3 & Others if needed. The values specified here are amounts reserved for those services while they are actively communicating.

The upstream bandwidth is usually the limiting factor, with lower speeds than download bandwidth. Set the reservation to account for the lower amount of upstream bandwidth available.

VoIP call audio (including MS Teams) with a high quality codec can use around 100Kb/s per call.
In this example, with around 1000Kb/s of upstream bandwidth and 1 user to consider, only 10% is reserved for Class 1.

WAN2 on DSL Routers

All WANs on Ethernet Routers

While QoS is not enabled, check the available bandwidth with a speed testing website.

Once you've determined the maximum bandwidth, set the Inbound/Outbound Bandwidth values to be maybe 5% lower than that maximum rate.

Setting a slightly lower value can give better overall performance, especially with time & latency sensitive traffic.

Click OK to apply the QoS settings.

The router will now begin to prioritise traffic passing through to the Internet, based on these Quality of Service settings.

Step 3 - Viewing QoS Statistics

To view the status and performance of Quality of Service, go to [Bandwidth Management] > [Quality of Service] and click the Status - Status link for the desired WAN interface:

This shows in real time how traffic is handled by the router.

The router allocates more bandwidth to the Class 1 & Class 2 traffic, while file transfers and video streaming classified as QoS Class "Other" continue to operate at a slightly slower speed:

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