Architecting Video Queue Management with Estimated Wait Time and Virtual Lobby Experiences

How-To-Articles
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Architecting Video Queue Management with Estimated Wait Time and Virtual Lobby Experiences

What This Guide Covers

This guide details the implementation of a high-fidelity video queuing system in Genesys Cloud CX that leverages the video media type, utilizes the Estimated Wait Time function for dynamic hold messaging, and orchestrates a virtual lobby experience via WebRTC signaling and custom UI integration. The end result is a contact center flow where video callers receive accurate wait time predictions, remain in a persistent WebRTC session without reconnection, and are presented with a branded virtual lobby interface while waiting for an available agent.

Prerequisites, Roles & Licensing

Licensing

  • CX 3 or CX 3+ License: Required for Video Queue functionality. Video queues are not supported on CX 1 or CX 2 licenses.
  • Engagement Platform License: Required if you intend to use the Virtual Lobby features tied to digital engagement handoffs or omnichannel routing logic.
  • Agent Desktop License: Agents must have a license that supports Video skills and the Genesys Cloud Agent Desktop (or a certified third-party client with WebRTC support).

Permissions & Roles

  • Architect > Flow > Edit: To create and modify the Media Flow and Architect flow logic.
  • Routing > Queue > Edit: To configure the Video Queue and assign skills.
  • Telephony > Video > Edit: To configure video trunk settings and ensure WebRTC signaling paths are open.
  • Integrations > API Integration > Edit: If using custom APIs to push wait time data to an external virtual lobby UI.

External Dependencies

  • WebRTC Endpoint: The caller must be using a Genesys Cloud WebRTC client, the Genesys Web Messenger with Video enabled, or a custom WebRTC implementation that adheres to the Genesys Cloud WebRTC SDK standards.
  • Network Configuration: UDP ports 10000–60000 must be open for media traffic. TCP ports 443 and 4443 must be open for signaling.
  • CDN/Static Hosting: If hosting a custom virtual lobby HTML/JS frontend, a secure static hosting provider (e.g., AWS S3, Azure Blob Storage) is required.

The Implementation Deep-Dive

1. Provisioning the Video Queue with Accurate Wait Time Metrics

The foundation of the virtual lobby experience is the underlying queue configuration. Unlike voice queues, video queues rely heavily on bandwidth negotiation and agent availability states that include video capability.

Configuration Steps

  1. Navigate to Admin > Routing > Queues.
  2. Click Add Queue.
  3. Set the Type to Video.
  4. Under Skills, assign a specific skill (e.g., Video_Support_Level_1). Ensure agents have this skill added to their profiles.
  5. Under Wait Time Calculation, ensure the default algorithm is set to Standard. This algorithm calculates the expected wait time based on historical handling times and current agent availability.

The Trap: Ignoring Agent Video Capability in Availability

A common misconfiguration is assigning agents to a video queue without verifying their Video Capability status. In Genesys Cloud, an agent can be “Available” for voice but “Not Available” for video if their profile does not have video enabled or if their device does not report video support.

If agents are marked as available for voice but not video, the queue’s estimated wait time will calculate based on the total pool of “Available” agents, leading to a massive discrepancy between the predicted wait time and the actual wait time. The system expects to route the video call to an agent who can handle video, but if the pool of video-capable agents is smaller than the general available pool, the wait time function will return an optimistic, incorrect value.

Solution: Enforce strict skill-based routing. Do not use general availability. Ensure the queue is configured to use Skill-Based Routing and that the assigned skill is exclusively used by agents who have video enabled in their profile. You can validate this by checking the Agent > Profiles section and ensuring the “Video” checkbox is enabled for all agents assigned to the Video_Support_Level_1 skill.

Architectural Reasoning

We use the Standard wait time calculation because it accounts for the variance in video handling times, which are typically longer than voice interactions due to screen sharing and visual troubleshooting. The Historical calculation method is less reliable for video because video interactions have higher variance in duration. The Standard method uses a rolling average that adapts faster to changes in agent performance and call complexity.

2. Designing the Media Flow for Virtual Lobby Integration

The Media Flow is responsible for managing the caller’s experience while they wait in the queue. For a virtual lobby, we do not simply play audio hold music. We need to maintain the WebRTC connection, potentially send data messages to the client UI, and provide real-time wait time updates.

Configuration Steps

  1. Navigate to Admin > Media > Media Flows.
  2. Create a new Media Flow named MF_Virtual_Lobby_Video.
  3. Set the Media Type to Video.
  4. In the Initial Action, select Play Prompt.
    • Upload a video prompt or a static image with background music. Note: Genesys Cloud supports video prompts (MP4/WebM) in media flows.
    • Set Loop to Yes.
  5. Add a Wait action.
    • Set Timeout to Never (or a maximum reasonable limit like 60 minutes).
    • Enable Estimated Wait Time. This allows the flow to expose the wait time variable to connected applications or subsequent actions.

The Trap: Breaking the WebRTC Session with Re-routing

A critical error in video architecture is attempting to “hang up” the video stream and re-initiate it to change the lobby content. WebRTC sessions are stateful and expensive to establish. If your flow logic disconnects the media stream to update a UI element, the caller’s browser will drop the peer connection, requiring a full renegotiation. This results in a black screen, audio dropout, and a poor user experience.

Solution: Keep the WebRTC session alive. Use the Play Prompt action with a looping video/image as the base layer. If you need to update dynamic content (like wait time), do not change the media flow action. Instead, use the Genesys Cloud WebRTC SDK or the Engagement API to push data to the client-side UI. The media flow should remain static in terms of media delivery, while the data layer handles dynamic updates.

Architectural Reasoning

We configure the Media Flow to loop a static video prompt because this consumes minimal server resources and ensures a consistent visual baseline for the caller. The dynamic elements (wait time, position in queue) are handled via data channels or API callbacks, not by swapping media assets. This separation of concerns ensures that media continuity is maintained regardless of how frequently the wait time updates.

3. Implementing Real-Time Wait Time Updates via API

To provide a true “Virtual Lobby” experience, the caller’s interface must display the estimated wait time dynamically. This requires integrating the Genesys Cloud API with the client-side application.

Step 3.1: Creating the API Endpoint

We will use the Routing > Queues > Interactions API to fetch the current wait time for a specific interaction.

Endpoint:

GET /api/v2/routing/queues/{queueId}/interactions/{interactionId}

OAuth Scope:
routing:interaction:view

JSON Response Snippet:

{
  "id": "interaction-uuid",
  "queueId": "queue-uuid",
  "estimatedWaitTimeSeconds": 120,
  "positionInQueue": 3,
  "status": "QUEUED"
}

Step 3.2: Client-Side Polling Strategy

On the client side (the virtual lobby UI), implement a polling mechanism that calls this endpoint every 10–15 seconds.

JavaScript Example (using Fetch API):

async function updateWaitTime(queueId, interactionId) {
  const url = `https://{{your-domain}}.mypurecloud.com/api/v2/routing/queues/${queueId}/interactions/${interactionId}`;
  
  try {
    const response = await fetch(url, {
      method: 'GET',
      headers: {
        'Authorization': 'Bearer {{access_token}}',
        'Content-Type': 'application/json'
      }
    });
    
    if (response.ok) {
      const data = await response.json();
      const waitSeconds = data.estimatedWaitTimeSeconds;
      
      // Update the UI
      document.getElementById('wait-time-display').innerText = 
        `Estimated Wait Time: ${Math.ceil(waitSeconds / 60)} minutes`;
    }
  } catch (error) {
    console.error('Failed to fetch wait time:', error);
  }
}

// Poll every 15 seconds
setInterval(() => {
  updateWaitTime('{{queueId}}', '{{interactionId}}');
}, 15000);

The Trap: API Rate Limiting and Token Expiry

Polling every 15 seconds for every concurrent video caller can quickly exhaust API rate limits, especially in high-volume environments. Additionally, the access token used for the API call may expire during a long wait, causing the UI to stop updating and potentially display errors.

Solution:

  1. Implement Exponential Backoff: If the API returns a 429 (Too Many Requests) error, double the polling interval and retry.
  2. Token Refresh Logic: Ensure your client-side application handles OAuth token refresh seamlessly. Use the refresh_token grant type to obtain a new access_token without user interaction.
  3. Server-Side Push (Advanced): For enterprise-scale deployments, consider using the Genesys Cloud Event Streams API or a webhook-based solution to push wait time updates to the client instead of polling. This reduces API load on the Genesys side and provides real-time updates.

Architectural Reasoning

We use polling in this example for simplicity and ease of implementation. However, in a production environment with hundreds of concurrent video calls, polling is not scalable. The architectural preference is to move to a Server-Sent Events (SSE) or WebSocket connection that pushes updates from a middleware server that subscribes to Genesys Cloud events. This decouples the UI from direct API calls to Genesys, allowing for better caching and rate-limit management.

4. Orchestrating the Virtual Lobby UI Handoff

The final piece is the handoff from the initial video connection to the virtual lobby UI. This requires a seamless transition where the video stream remains active while the UI overlays the lobby content.

Configuration Steps

  1. Custom WebRTC Client Integration: If using a custom client, ensure the onMediaSessionStateChange event handler detects when the caller enters the queue.
  2. UI Overlay: When the state changes to QUEUED, display the virtual lobby overlay. This overlay should include:
    • The estimated wait time (fetched via API).
    • The position in the queue.
    • A “Cancel Wait” button that triggers an API call to abandon the interaction.
    • Branded content (videos, FAQs) to keep the caller engaged.

The Trap: Abandonment Logic Misconfiguration

When a caller clicks “Cancel Wait” in the virtual lobby, the UI must send an ABANDON signal to the Genesys Cloud API. If this is not handled correctly, the caller may remain in the queue indefinitely, consuming resources and skewing wait time metrics.

Solution: Use the Routing > Interactions > Abandon API.

Endpoint:

POST /api/v2/routing/interactions/{interactionId}/abandon

JSON Body:

{
  "reason": "CALLER_REQUESTED"
}

Ensure the UI calls this endpoint immediately upon user request. Also, handle the response asynchronously to ensure the UI updates to reflect the abandonment before the media session is torn down by the server.

Architectural Reasoning

The virtual lobby UI is not just a passive display; it is an active control plane for the interaction. By providing the caller with control (abandon, callback request), we reduce forced abandons and improve customer satisfaction. The architecture must treat the UI as a first-class citizen in the routing logic, with clear bidirectional communication channels between the UI and the Genesys Cloud backend.

Validation, Edge Cases & Troubleshooting

Edge Case 1: WebRTC ICE Candidate Failure in Corporate Networks

The Failure Condition:
The caller connects to the virtual lobby, but the video stream is black, and audio is silent. The wait time updates correctly, indicating the queue logic is working, but the media path is broken.

The Root Cause:
Corporate firewalls often block UDP traffic, which is required for WebRTC media. If the ICE (Interactive Connectivity Establishment) negotiation fails to find a direct path, it falls back to TURN servers. If the Genesys Cloud tenant is not configured with proper TURN servers, or if the corporate firewall blocks the TURN server ports, the media will fail.

The Solution:

  1. Verify TURN Configuration: Ensure your Genesys Cloud tenant has TURN servers configured. Navigate to Admin > Telephony > Video > TURN Servers.
  2. Check Firewall Rules: Ensure that UDP ports 3478 and 443 (for TURN over TLS) are open outbound from the caller’s network.
  3. Debug ICE Logs: Enable WebRTC logging in the browser developer tools (Chrome: chrome://webrtc-internals) to inspect the ICE candidate exchange. Look for host, srflx, and relay candidates. If only host candidates are present and the connection fails, the issue is NAT traversal.

Edge Case 2: Discrepancy Between Estimated Wait Time and Actual Wait Time

The Failure Condition:
The virtual lobby displays an estimated wait time of 2 minutes, but the caller waits for 10 minutes. This leads to customer frustration and abandonment.

The Root Cause:
The Standard wait time calculation relies on historical data. If the queue has recently experienced a spike in volume or a drop in agent availability, the historical average may not reflect the current reality. Additionally, if agents are taking calls out of order (e.g., manually answering a priority call), the queue position logic breaks down.

The Solution:

  1. Adjust Wait Time Buffer: In the Media Flow, you can add a buffer to the estimated wait time. For example, if the API returns 120 seconds, display 150 seconds to account for variance.
  2. Monitor Agent Behavior: Use WEM (Workforce Engagement Management) to monitor agent adherence. Ensure agents are not manually overriding routing decisions.
  3. Use Real-Time Analytics: Integrate with the Genesys Cloud Real-Time Dashboard to monitor queue length and agent availability. If the wait time exceeds a threshold, trigger an alert to supervisors to add more agents or enable callback options.

Edge Case 3: Video Codec Mismatch

The Failure Condition:
The caller and agent both connect, but the video is distorted, laggy, or has poor quality. Audio is fine.

The Root Cause:
WebRTC supports multiple video codecs (VP8, VP9, H.264). If the caller’s browser supports VP8 but the agent’s client only supports H.264, and the server does not transcode, the negotiation may fail or fall back to a low-quality codec.

The Solution:

  1. Standardize Codecs: Configure the Genesys Cloud video settings to prefer a common codec, such as VP8. Navigate to Admin > Telephony > Video > Codec Preferences.
  2. Ensure Browser Compatibility: Ensure both the caller and agent are using modern browsers that support VP8/VP9. Avoid using outdated browsers or non-standard WebRTC implementations.
  3. Monitor Bandwidth: Use the Genesys Cloud Media Quality Dashboard to monitor video bitrate and packet loss. If packet loss is high, the video quality will degrade regardless of codec.

Official References