Creating a new SMS Trunk Group

SMS Trunk Groups are used for providing link redundancy, allowing traffic to be routed on alternative trunks if an active trunk fails. Trunks within a Trunk Group are allocated priorities that rank the order in which those trunks should be used. In addition, users may optionally build custom re-routing rules that are based on SIP response codes, and define the conditions under which a trunk is considered to be “in service”.

SMS Trunk Groups are created as follows:

Step 1. Using the menu on the left-hand side of the page, navigate to the “Trunks” section, select “SMS Trunks”, click the “+Add SMS Trunk” button, and choose the “Trunk Group” option (Fig. 1).


Fig. 1. Adding a new SMS Trunk Group.

Step 2. Create the Trunk Group. There are three parameters to be configured (See Fig. 2):

  • Friendly name – The name that will identify this SMS Trunk Group on the DIDWW user panel.

  • Choose SMS Trunks – Add SMS trunks to this SMS Trunk Group. A drop-down list of all previously configured SMS trunks that are not currently part of a Trunk Group will be displayed, and up to 10 SMS trunks may be added to this Trunk Group.

  • Map all DID(s) – If checked, all DIDs on your account with SMS capabilities will be assigned to this SMS Trunk Group.


Fig. 2. Create trunk group window

Step 3. Click “Submit” to complete the Trunk Group configuration.

Step 4. Define trunk priority values within the Trunk Group for SMS trunk failover sequences. There are two methods of configuring failover priorities:

Setting the priority simultaneoulsy for all trunks within the SMS TrunkGroup

Clicking on the “+” on the left-hand side of the configured SMS Trunk Group displays all of the trunks within that group (See Fig. 3). The priority of each trunk may be set to a value from 0 and 65,535, with the lowest number representing the highest priority. For example, consider a Trunk Group with three trunks of priority 0, and two trunks with a priority of 1. The two trunks with the higher value of 1 will only be used if all three trunks with priority 0 are unavailable.


Fig. 3. Trunk group details

Setting the priority individually for all trunks within the SMS Trunk Group

Clicking on the “Edit” button for an individual SMS trunk (Fig. 4) opens a trunk configuration window.


Fig. 4. Opening the trunk configuration window

Select “Trunk group configuration” to view the Trunk Group configuration parameters (Fig. 5).


Fig. 5. Accessing the Trunk Group configuration parameters

There are two parameters to be configured, the trunk priority and the trunk re-routing rules (See Fig. 6).


Fig. 6. SMS Trunk group configuration windows

Priority - The priority for this trunk (valid values from 0 and 65,535), with the lowest number representing the highest priority.

Re-routing rules - Defines the conditions for which a trunk is defined to be “in service” and thus discontinue re-routing. These rules are based on standard SIP response codes, together with proprietary DIDWW failure conditions. “Available success response codes” is a list of response codes which may be selected to form the re-routing rules. The “Success response codes” are those codes which discontinue trunk re-routing. By default, trunk rerouting is discontinued on receipt of a SIP response code 00 (No Error). In order to build proprietary re-routing rules:

  1. Deselect the “Use Default Success Response Rules” flag.

  2. Select an option from the list of “Available success response codes”.

  3. Use the “>>” button to add that option to the “Success response codes” list (see Fig.7).

  4. Continue with steps 2 and 3 until the required trunk re-routing rule has been built.

  5. Response options may be removed from the “Success response codes” list by using the “<<” button.


Fig. 7. Adding success response codes

Once the trunk priority and the trunk re-routing rules have been configured, click “Submit” to save the trunk configuration.


DID number(-s) could be assigned to just created SMS Trunk Group in the same manner as regular SMS Trunk.