Load Balancing FusionPBX Outbound Gateways

In certain situations you want to load balance SIP traffic between multiple SIP endpoints. These SIP endpoints are typically a Session Border Controller (SBC) in your organization or an upstream SIP provider. In any case, you need some logic that will distribute the traffic between the SIP endpoints. In the FusionPBX world (which is based on FreeSWITCH) this module is called Distributor (mod_distributor). In this article we will explain how to configure it.


  • You have at least two gateways defined within FusionPBX, which represents the SIP endpoints that you want to distribute traffic between.

Configuration Steps

  1. Login to FusionPBX and make sure the mod_distributor module is enabled. You can do so by going under Advanced -> Modules. Distributor should be an option to choose from, but should be disabled.  It will need to be enabled. “Enabled” should read True on the distributor line once it’s enabled.
  2. Get Gateway ID’s – right click on the Gateway name and click “Copy Address”. Open up a text editor and paste the address. The Gateway ID is the string after “id=” in the URL. Do this for all of the gateways you want to distribute traffic too.
3. Changing the mod_distributor config xml:
  • SSH to your FusionPBX server, make your way into the /etc/freeswitch directory
  • Using your favorite editor, edit autoload_configs/distributor.conf.xml and add the following:
<list name="my_list_001" total-weight="2">
<node name="978fefdd-45cd-4457-8ecd-5d82eaea3b12" weight="1"/> <!-- my_gateway_001 - its just comment with actual GW name -->
<node name="1a8d448d-e06e-2dab-b6f9-4421a98e4d8e" weight="1"/> <!-- my_gateway_002 -->
4. Save and run the following commands from the FreeSWITCH cli
fs_cli > reloadxml
fs_cli > distributor_ctl reload
5. Updated your Outbound Routing setting. You have something like this now: But, you want to change the last line to something like this: The Distributor command above takes a string value that contains a list that was defined in distributor.conf.xml and returns a gateway based on the weight defined in the configuration. In this case, “my_list_001” is the list used. This module can be used for other use cases where you need to generate random/weighted values.