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MikroTik MTCTCE lab 3 of 8

HTB queue trees: structure, dual limitation, priority and DSCP

Riverside's phones share the uplink with everyone's downloads, and calls break up whenever someone pulls a big file. The voice provider already marks its packets with DSCP 46. Classify by DSCP with mangle, build an HTB queue tree with a guaranteed rate and top priority for voice, and measure how HTB shares the link when both classes are busy.

Run this lab

It needs Lite: its 4 nodes are set to 4 vCPU and 1,024 MB in total. That fits the free demo too.

In your workspace: Shared, then MikroTik MTCTCE RouterOS v7 guided labs, then 03 - HTB queue trees - structure dual limitation priority and DSCP

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Level
Advanced
Time
About 60 minutes
Nodes need
4 vCPU, 1,024 MB
Smallest plan
Lite

The scenario

Riverside's phone system (VOICE, 192.168.50.11) and the staff PCs share the office's downlink. When someone starts a big download, calls break up. The voice provider already marks its packets DSCP 46 (EF) on the way in. You'll build an HTB queue tree on the LAN interface that guarantees voice a share, gives it priority over everything else, and lets downloads use whatever is left.

Rates are in kbit/s because of the CHR licence's cap (lab 2 explains); the shape of the tree is what matters.

DeviceAddressRole
NET192.0.2.1/30the Internet, bandwidth-test server; marks traffic to VOICE as DSCP 46
RIVERSIDEether1 192.0.2.2/30 · ether2 192.168.50.1/24the office router
VOICE192.168.50.11the phone system's gateway (RouterOS)
PC2192.168.50.12a staff PC (RouterOS)

What you’ll practise

  • Explain HTB's inner and leaf queues, and how limit-at, max-limit and priority share bandwidth
  • Classify traffic by DSCP with mangle packet marks
  • Build a queue tree on an interface with a parent and two leaf classes
  • Measure dual limitation and priority with two simultaneous downloads
  • Map DSCP to RouterOS priority with set-priority

The tasks

  1. Watch voice suffer
  2. Classify by DSCP
  3. Build the HTB tree
  4. Measure the sharing

The Lab Tasks pane has the scenario, these tasks, the checks to run, hints and the full solution.

Topology and devices

The network as it opens in EVE-NG, drawn from the lab’s own canvas, and the image each node runs.

Topology of HTB queue trees - structure dual limitation priority and DSCP4 nodes and 1 network, 4 links. Every link is listed as text below the diagram.NETRIVERSIDEVOICEPC2Officeether2ether1ether1ether1ether1
4 nodes and 1 network, with the interface names each link uses. On a narrow screen, scroll the diagram sideways.
Every link, as text
  • NET ether1 to RIVERSIDE ether1
  • RIVERSIDE ether2 to Office (network)
  • VOICE ether1 to Office (network)
  • PC2 ether1 to Office (network)
Nodes in HTB queue trees: structure, dual limitation, priority and DSCP, with the image each runs and the vCPU and RAM it’s set to
NodeDeviceImage in Add NodeSet to
NETMikroTik RouterOSmikrotik-7.14.21 vCPU, 256 MB
RIVERSIDEMikroTik RouterOSmikrotik-7.14.21 vCPU, 256 MB
VOICEMikroTik RouterOSmikrotik-7.14.21 vCPU, 256 MB
PC2MikroTik RouterOSmikrotik-7.14.21 vCPU, 256 MB

How to open this lab

  1. Sign in to your workspace at lab.cloudlabbox.com.

  2. In File Manager, open Shared, then the folder MikroTik MTCTCE RouterOS v7 guided labs.

  3. Open 03 - HTB queue trees - structure dual limitation priority and DSCP and start its nodes, then open Lab Tasks for the scenario and the steps.

The lab is read-only. You can start the nodes and configure the devices, but changes to the topology can’t be saved. To change it, rebuild it in your own folder.

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CloudLabBox is independent of MikroTik. The lab follows exam topics and isn’t vendor training material; vendor names identify the exams and the images in the workspace.