On Premises

Overflow Threshold Algorithms


A dynamic Overflow Threshold Algorithm compares the number of incoming calls to the number of available agents (that are not offline) and calculates the Overflow Threshold. From this value on all incoming further calls will hear the Overflow Message after which the call will be disconnected. Optional a Call back can be introduced to those callers, before they get disconnected.

The static Overflow Threshold is defined by default up until 999 callers, that means that only after this value, the calls will not be connected to the UCC A Unified Contact Center, or UCC, is a queue of interactions (voice, email, IM, etc.) that are handled by Agents. Each UCC has its own settings, IVR menus and Agents. Agents can belong to one or several UCCs and can have multiple skills (competencies). A UCC can be visualized as a contact center “micro service”. Customers can utilize one UCC (e.g. a global helpdesk), a few UCC’s (e.g. for each department or regional office) or hundreds of UCC’s (e.g. for each bed at a hospital). They are interconnected and can all be managed from one central location..

Overflow Threshold calculations that are currently available:

  • Static calculation = when the number of callers in the waiting queue reaches the Overflow Threshold – queue limit is reached and the Overflow Message will be played

  • Dynamic calculation = N x Total Active Agents (that are not offline) – queue limit is reached and the Overflow Message will be played

    N = OverflowActiveAgentsRatio

Example If N = 1.2 and the number of active Agents = 5, then the Overflow Threshold is 6


Note: The Overflow Threshold is enabled by default up until 999, if no other value is entered the value StaticTreshold will be assumed.

The configuration of the Overflow Threshold Algorithm can be done in the UCC Settings via the UCC SharePoint Dashboard.

To enable dynamic calculation:

Navigate to the UCC GENERAL widget, open the Settings, and click + new item.






(enum StaticTreshold|ActiveAgentsThreshold)

The Overflow Threshold is used by the UCC.



(enter a decimal, e.g. 1.5)

Overflow is reached when the number of callers in the queue exceeds OverflowActiveAgentsRatio * ActiveAgents.


The use of the Overflow conversations item in reports

When a caller contacts the UCC and the overflow has been reached, then she / he will hear the Overflow Message. Supervisors can retrieve information about the number of Overflow conversations in the UCC Report or quickly check the conversation type ‘Overflow’ in the Dialogue Overview. Learn more about Dialogue Intelligence and browse the collection of available reports.

Overflow Type displays in reports as:

Related Topics

UCC Settings

How to configure Callback

Example configuration Microsoft Power Automate to schedule callback when a dialogue is missed