In the world of business communications, ensuring that every call is handled efficiently and professionally is critical to customer satisfaction and internal collaboration. One essential feature that helps organizations manage incoming calls effectively is the call queue. But what exactly is a call queue, and how does it work across today’s leading collaboration and calling platforms like Cisco UCM, Webex Calling, Microsoft Teams Phone, and Zoom Phone?
Let’s break it down.
What Is a Call Queue?
Have you ever called a customer service number and were met with a message stating, “Your call is important to us, please remain on the line for the next available customer service representative.” Congratulations! You’ve been in a call queue.
A call queue is a phone system feature used to manage incoming calls by placing callers into a virtual “line.” This occurs when all available agents or users are busy and unable to answer the phone call. Instead of going straight to voicemail or receiving a busy signal, callers are held in the queue and routed to the next available person based on defined rules like round robin, longest idle, or skills-based routing.
Call queues are common in:
Customer service and support centers.
Internal or external IT help desks.
Sales departments.
Reception or main-line routing.
Call queues ensure that no call goes unanswered and provide a consistent experience, often with music, estimated wait times, and position-in-line announcements to keep callers informed.
Call Queues in Cisco UCM (Unified Communications Manager)
With Cisco Unified Communications Manager (UCM), call queues are typically implemented through hunt groups and line groups. These tools distribute calls across multiple users based on algorithms like broadcast, circular, or longest idle.
Key Capabilities
Queue up to 100 calls per hunt pilot.
Configurable announcements (e.g., greeting, wait time messages, comfort messages).
Custom hold music.
Maximum wait time and queue size settings.
Overflow handling (e.g., route to voicemail, another number, or hang up).
Call distribution algorithms like longest idle, circular, broadcast, etc.
The native call queuing feature in Cisco UCM is a basic queuing capability introduced in later versions (starting with UCM 10.x) to help manage inbound calls when all hunt group members (agents) are busy. While it's not a full contact center solution like Cisco UCCX or Webex Contact Center, it provides simple queuing functionality suitable for small teams, departments, or front desk scenarios.
Call Queues in Webex Calling
Call queues in Webex Calling are a native feature that manages incoming calls by placing callers into a virtual waiting line when all agents or team members assigned to the queue are busy. As soon as someone becomes available, the call is routed based on your configured distribution method.
This functionality is designed for businesses that want to provide a professional, consistent caller experience — even during high call volume — without requiring a full contact center solution.
Built-in Capabilities
Custom Greetings and Announcements: Set up welcome messages, estimated wait time messages, and comfort messages to reassure callers.
Hold Music: Upload your own audio files or use system defaults for music callers will hear while waiting.
Queue Capacity Limits: Set a maximum number of callers in queue. Overflow behavior can route excess calls to voicemail, another number, or a different call queue.
Wait Time Settings: Define how long a caller can wait before being routed elsewhere.
Agent Availability and Call Routing: Use different algorithms to determine who receives the next call:
Longest Idle.
Round Robin.
Simultaneous Ring.
Weighted Call Distribution.
Analytics and Reporting (via Webex Control Hub): Basic queue performance metrics like:
Average wait time.
Call volume.
Abandoned calls.
Answered calls.
Agent Status Options: Agents can sign in or out of the queue and set themselves as available/unavailable.
Webex Calling queues are managed in Control Hub, making them easy to administer centrally for organizations with hybrid or remote workforces.
Webex Calling’s native call queue feature gives organizations a flexible, user-friendly way to route and manage inbound calls, perfect for teams who want reliable, professional queuing without the complexity of a contact center.
Call Queues in Microsoft Teams Phone
Call queues in Microsoft Teams Phone are a built-in feature that help organizations efficiently manage incoming calls by placing callers into a virtual line (queue) until the next available user (agent) can answer. They are especially useful for departments like sales, support, IT help desks, and reception.
When all assigned users are busy, Teams keeps the caller on hold, plays music or custom greetings, and distributes calls based on predefined routing rules.
Core Capabilities
Welcome Greeting: Play a recorded message when a call enters the queue.
Music on Hold: Keep callers engaged while they wait. Microsoft provides default music, or you can upload a custom audio file.
Call Distribution Methods: Choose how calls are routed to available users.
Attendant routing: Rings all agents at once.
Serial routing: Routes calls in a fixed order.
Round robin: Distributes calls evenly among agents.
Longest idle: Prioritizes agents who have been idle the longest.
Agent Opt-in/Opt-out: Agents can manually opt in or out of call queues in the Teams client.
Timeout and Overflow Handling: Define what happens if a caller waits too long or if no one is available (e.g., redirect to voicemail, another queue, or a specific user).
Custom Business Hours and Holidays: Set working hours and create specific rules for after-hours and holidays.
Administrators can configure queues within the Microsoft Teams Admin Center, often in conjunction with Microsoft Entra ID (Azure AD) groups to manage call agents.
Call Queues in Zoom Phone
Call queues in Zoom Phone are a built-in feature that allow organizations to manage incoming calls by placing callers into a virtual line when all assigned users (agents) are busy. Zoom Phone then routes those calls based on configurable distribution methods and queue logic.
Zoom Phone also supports call monitoring tools like whisper and barge-in, which are useful for supervisors overseeing queue performance and coaching agents in real time.
Core Capabilities
Custom Greeting and Hold Music: Upload audio files or use defaults for greetings, waiting messages, and music on hold.
Call Distribution Options: Choose how calls are routed to agents:
Simultaneous: Rings all available members.
Sequential: Rings agents one at a time in a defined order.
Rotating: Distributes calls in a rotating order.
Longest Idle: Prioritizes the agent who has been idle the longest.
Overflow and Max Wait Handling: Set the maximum number of calls in the queue or wait time per caller. You can define what happens next — send to voicemail, another queue, user, or play a message and hang up.
Business Hours and Holiday Routing: Define rules based on the time of day or day of the week, including alternate routing outside of business hours.
Agent Sign-In/Sign-Out: Agents can toggle their availability to receive queue calls in the Zoom app.
Live Call Monitoring: Supervisors (if granted permissions) can listen, whisper, or barge into calls for coaching and support.
Reporting and Analytics: Zoom’s admin portal offers basic call queue metrics, such as:
Call volume.
Answer rate.
Abandonment rate.
Wait times. (Advanced reporting may require a Zoom Phone Power Pack add-on.)
Call Queue Feature Comparison: Cisco UCM vs Webex Calling vs Microsoft Teams vs Zoom Phone
Feature/Platform
Cisco UCM
Webex Calling
Microsoft Teams Phone
Zoom Phone
Call Queueing Support
Basic (Native Hunt Group)
Built-in
Built-in
Built-in
Max Calls in Queue
Up to 100 per Hunt Pilot
Configurable
Configurable
Configurable
Call Distribution Methods
Broadcast, Longest Idle, etc.
Round Robin, Longest Idle, etc.
Attendant, Round Robin, Longest Idle
Simultaneous, Sequential, Longest Idle
Custom Greetings & Hold Music
Yes (Basic Audio Files)
Yes
Yes
Yes
Music on Hold Customization
Yes
Yes
Yes
Yes
Overflow & Timeout Handling
Yes (Limited)
Yes
Yes
Yes
Business Hours / Holiday Routing
Limited
Yes
Yes
Yes
Agent Sign In/Out Control
No native presence awareness
Yes
Yes (via Teams client)
Yes (via Zoom client)
Presence Awareness (Available/Busy)
No native support
Yes
Yes
Yes
Call Queue Reporting
None
Basic (Control Hub)
Basic (CQD/Admin Center)
Basic (enhanced with Power Pack)
Live Monitoring / Barge / Whisper
No
No
No (3rd party needed)
Yes (with Power Pack)
Agent Desktop / Supervisor Tools
No
No
No (3rd party options available)
Partial (via Zoom app + add-ons)
Skills-Based Routing
No
No
No
No
IVR / Auto Attendant Integration
Basic via CUCM AA
Yes
Yes (Teams Auto Attendants)
Yes (Zoom Auto Receptionist)
CRM / API Integration
Possible with 3rd party
Limited
Limited
Limited
Third-Party Reporting Support
Needed (e.g., Variphy)
(e.g., Variphy)
Required for deep insights
Required for advanced analytics
Best Use Case
Small teams with simple needs
Departments needing easy cloud queues
Organizations using Microsoft 365
SMBs to mid-size teams on Zoom
Why Call Queues Matter
Whether you’re a small support team or a global enterprise, call queues improve caller experience, reduce wait times, and optimize agent productivity. When implemented effectively, they ensure that every call is handled professionally and efficiently.
Each platform offers unique capabilities, so understanding your organization's needs is key when choosing or configuring your call queue setup.
Optimize Your Call Queues With the Right Tools
Call queues are vital for delivering responsive communication and service. Whether you're using Cisco UCM, Webex Calling, Microsoft Teams Phone, or Zoom Phone, leveraging call queue features effectively can transform how you manage inbound voice traffic.
If you're looking to analyze, report on, or optimize your call queues, platforms like Variphy can provide visibility into performance metrics across these systems. so you can make smarter, data-driven decisions about staffing, call handling, and user experience.
