Controlling bandwidth usage with Virtual Links in the GUI

FASP transfers attempt to transfer at the maximum transfer rate available. However, too many simultaneous transfers can overwhelm your storage or leave little bandwidth available for other network activity. To set a bandwidth cap on the total bandwidth that is used by incoming or outgoing transfer sessions initiated by all users, or sets of specific users, set up a virtual link (Vlink).

Vlinks are virtual bandwidth caps, in that they are not assigned to a specific transfer session, but to all sessions assigned to the same Vlink. The total bandwidth that is used by all incoming or outgoing transfer sessions that are initiated by users who are assigned to the same Vlink does not exceed the Vlink capacity.

For example, if you want to limit all incoming FASP transfers to 100 Mbps, you can create a Vlink with a 100 Mbps capacity and assign it globally to all incoming transfers. If a user attempts an upload at 50 Mbps but other incoming transfers are already using 75 Mbps, then the transfer rates adjust (based on transfer policy) so that the total does not exceed 100 Mbps.

For another example, if you want to limit to 10 Mbps the total bandwidth that is used by outgoing FASP transfers (downloads) that are initiated by three specific users, create a Vlink with a 10 Mbps capacity and assign it to outgoing transfers for those three users. For example, if the three users are running download sessions that already use 10 Mbps and another download is started by one of the users, the transfer rates of all sessions adjust so that the total bandwidth use by those users remains 10 Mbps. Transfers by other users that are not assigned the Vlink are not affected, except to use available bandwidth when the Vlink capacity is not met.

  1. Start the application with administrator privileges.
  2. Click Configuration > Vlinks.
  3. Create a Vlink.
    Click Add Vlink to add a Vlink entry and enter a number in the range 1 - 255 and click OK.

    Add a Vlink by clicking the plus sign.

  4. Configure the Vlink.
    When the Vlink is created, name it, activate it, and set the bandwidth capacity cap. See the following table for details.
  5. Apply a Vlink to users.
    Assign a Vlink to global or user settings. The example assigns a Vlink to a user's incoming transfer session.

    In the Configuration window, click the Users tab and select the user to whose transfers you want to apply the Vlink. In the right panel, click the Bandwidth tab, select the override box in the Incoming Vlink ID row and select the Vlink to apply from the drop-down menu:

    Assign a Vlink to a user
  6. Prevent users from overriding the Vlink settings.
    If a user requests a minimum rate that exceeds the Vlink and minimum rates are not locked, the transfer can exceed Vlink limits. To prevent this behavior, follow these steps: