Interface bandwidth limits

This article applies to our On-Premise Appliance Filter and Firewall product only, not to Cloud.

 

You can limit the available bandwidth for incoming and outgoing traffic, for each interface on your Smoothwall.

Bandwidth limits for an interface

Before you begin

Ensure you have all your interfaces set up correctly.

Create a bandwidth limit

  1. Go to Bandwidth > Control > Interfaces.
  2. Select Add new interface limit and ensure Enabled is selected.
  3. Select the interface to which the limit is applied. You can’t select interfaces already used in a policy.
  4. Enter the Maximum bandwidth in and Maximum bandwidth out in kbps or Mbps. This controls the incoming and outgoing bandwidth for this interface.

    Tip

    • We recommend you set limits at or above 20 kbps, as smaller limits can’t reliably limit traffic.
    • Set limits to be slightly less than (around 95%) of the expected maximum throughput of that interface to avoid packet queues.
  5. Select Add.

Edit or delete a bandwidth limit for an interface

Go to Bandwidth > Control > Interfaces and hover over the interface limit.

  • To delete, select Delete. In the window, select Delete.
  • To edit:
    1. Select Edit.
    2. Make the required changes.
    3. Select Save Changes.
    4. If you have changed the Maximum bandwidth in and Maximum bandwidth out, check and adjust the bandwidth shares for the class assigned to the interface.

Edit bandwidth shares for classes

Before you begin

If you don’t have classes, the bandwidth limit for the interface automatically applies to all traffic. Add classes to set different bandwidth shares for different IP addresses.

Edit the bandwidth shares

Every class is automatically given the bandwidth limit of the interface, but you can amend this.

  1. Go to Bandwidth > Control > Interfaces.
  2. Select the interface name to expand it to see the Bandwidth shares section.
  3. Hover over the class you want to amend and select Edit.
  4. Manage the bandwidth limits:
    • Leave the Maximum bandwidth in and Maximum bandwidth out as Use interface limits.
    • Enter a ‘slice’ of the incoming and outgoing bandwidth in kbps or Mbps.
  5. Select the share Type:

    Note

    When using the Dynamic and Per user types, you can set a higher Maximum bandwidth for the class than for the interface. If one class is allocated 200% of the bandwidth, and another 100%, both can use the whole interface bandwidth individually. However, when both are in use at the same time, bandwidth is allocated using a 2:1 ratio.

    • Dynamic: This is the default type. Using this type, classes can use more bandwidth when it's spare but share fairly when it's in demand. Commonly used for non-critical services that don’t need guaranteed bandwidth.
    • Guaranteed: This type protects essential traffic in the event of excessive demand from other classes.
    • Per user: This type ensures that users receive a fair share of bandwidth, unaffected by the usage of other users in the same class. Commonly used for networks where users are not running critical applications, such as for individual hotel guests or BYO device setups.
  6. Select Save changes.