Trunk Groups

Trunk Groups 'group' Trunks together to allow fail over and least cost routing across trunks.

Each time a call is made the following logic is applied to the call routing by the Trunk Group.

Determine the Trunk Group

When dialing a number unless an explict Trunk Group has been set then the Trunk Group marked as 'default' will be used.

Trunk Groups can be explicitly selected when creating a Handset and from a Campaign Template.

Check Exceptions

The dialed number is compared against the list of exceptions for the selected Trunk Group. If the number matches the call is rejected and an 'The number dialed is invalid' message is played.

Exceptions can be used to exclude international dialing or calls to premium services (e.g. 1902 numbers).

Match Patterns

When matching patterns normally on the Patterns that are marked as 'Primary' are considered. If the Trunk Group is put into Fail Over mode then only the Patterns marked as 'Failover' are considered.

The Trunk Group searches the set of Patterns in priority order (top of the list of patterns to the bottom). The first pattern that matches the dialed phone number is selected.

The trunks 'Call Limit' is then checked against the number of active calls on that trunk. If the new call we cause the call limit to be exceeded then search through the set of patterns will resume.

If the all patterns are searched and none match or all of the trunks are are congested then the caller will be played a message 'No lines are available'.

Failover

Trunk Groups provide a 'fail over' mechanism in case the primary voice provider (ITSP) systems fail or your connection to their system fails. The fail over mechanism allows you to have a Primary trunk and a failover trunk via an alterate voice provider. The 'Fail Over' button on the Trunk Group details page will force all calls to be routed to the set of Trunks with the Mode of 'Fail Over'.

When setting up Patterns you will have at least one patterns with a mode of Primary. If you are doing least cost routing then you will have multiple primary patterns. To use the Fail Over feature you will normally have a single Pattern of mode 'Failover'. When the Trunk Group is put into Fail Over mode then only the Patterns of mode Failover will be considered when routing a call.

Fields

Field	Description
Name	The name of the trunk group.
Description	A description of what the Trunk Group is used for that will be meaningful to you in two years time.
Default	If ticked then this Trunk Group is the default trunk group and will be used by default when creating new Handsets or when a call is made where a Trunk Group hasn't been set explicity. Only one Trunk Group may be marked as default.
Mode	Indicates whether this Trunk Group is in Primary or Failover mode.
Fail Over/Primary button	If you click the button when it says 'Fail Over' then you will force the system into the Fail over mode. If you click the button when it says 'Primary' then you will force the system into the Primary mode. When the system's mode changes it will immediately affect any new calls. Existing calls will still be going via the original Trunk Group.