Knowledge Center

Traffic Control

Traffic control (at Control Panel > Network > Traffic Control) aims to control the outgoing traffic of services running on Synology NAS. Once you have selected a service, you need to specify the Guaranteed Bandwidth and Maximum Bandwidth to limit its outgoing traffic.

Term Explanation

  • Guaranteed Bandwidth: Defines the outgoing traffic a service guarantees to serve when the whole system bandwidth is wide enough.
  • Maximum Bandwidth: Defines the outgoing traffic this service can borrow when the whole system bandwidth is enough and there is System Remaining Bandwidth. We suggest calculating System Output Bandwidth first. Then, make sure the sum of Guaranteed Bandwidth for each service is not greater than System Output Bandwidth, or the setting may not work correctly.

Setting Formula

  • System Output Bandwidth = Total Guaranteed Bandwidth of all services + System Remaining Bandwidth
  • Guaranteed Bandwidth for each service ≤ Maximum Bandwidth for each service

Note:

If the outgoing packets do not match any traffic control rules, the default behavior will be no limitation. You can add your own default traffic control rule at the end of all rules by choosing All ports, and specify Guaranteed Bandwidth and Maximum Bandwidth.

To create a traffic control rule:

  1. Select a network interface from the drop-down menu in the upper right corner.
  2. Click Create.
  3. In the Ports section, select one of the following for the rule:
    • Choose All to apply the rule to all ports.
    • Choose Select from a list of built-in applications.
    • Choose Custom and click Custom, and then enter up to 15 ports separated with comma, or specify a port range.
    • You can also specify the protocols.

Now you can see the created traffic control rule in the rule list.

To delete traffic control rules, do either of the following:

  • Uncheck the checkbox of the rule in the Enabled column of the list.
  • Delete the traffic control rule.

Note:

  1. You can create up to 100 rules for a network interface.
  2. Drag-and-drop to reorder the rules in the list.
  3. Rules are prioritized according to their positions in the list.
  4. If you have multiple network ports connecting to the same subnet, the firewall rules may not work properly.*
  5. If your Synology NAS device connects to the Internet via PPPoE, the related traffic control rules must be configured on the corresponding PPPoE interface.

____
* Applies to specific models only.