In brief: 3CX V20 Update 2 brought significant improvements to call quality, the web client, and mobile apps. This guide covers the changes that matter most for SA resellers managing 3CX deployments and what to check when updating existing customers.
3CX V20: The Architecture Shift
3CX V20 represented the most significant architectural change in 3CX’s history since the move to browser-based management in V18. The V20 release rebuilt 3CX around a containerised infrastructure using Docker, making deployments more portable, scalable, and easier to update. For resellers hosting 3CX instances on behalf of clients, V20 introduced a more robust multi-tenant hosting model that simplified the management of multiple customer instances from a single server.
The V20 release also marked 3CX’s definitive move away from on-premise hardware deployments toward cloud-hosted and hybrid models. While 3CX can still run on physical hardware, the recommended and best-supported deployment model is now cloud-hosted — either on 3CX’s own hosted infrastructure or on customer-managed VMs in major cloud providers (AWS, Google Cloud, Microsoft Azure, Hetzner).
What’s New in V20 Update 2
V20 Update 2 (released July 2024) addressed a range of issues identified in the initial V20 release and added new functionality:
Improved call quality: V20 U2 included refinements to 3CX’s WebRTC audio stack, reducing echo and improving call clarity for web client calls. Resellers who had received complaints about audio quality on browser-based calls should note that U2 addresses many of these issues without client-side configuration changes.
Enhanced iOS app performance: The 3CX iOS app was updated to work more reliably in the background on iOS 15 and later, addressing a persistent problem where calls would fail to ring when the app was not in the foreground. Clients who had been using desk phones instead of softphones specifically because of this issue should be encouraged to test the updated app.
Web client improvements: The V20 web client received improvements to presence display, chat history loading, and the meeting/video call interface. The contact search function was also optimised for speed, which is noticeable for larger deployments with thousands of extension entries.
Call recording enhancements: V20 U2 improved the reliability of call recording, particularly for calls that involve transfer operations. Resellers managing contact centre deployments with call recording requirements should verify that recordings of transferred calls are being captured correctly after updating.
API updates: The 3CX REST API was extended in U2 with additional endpoints for queue management and reporting, enabling better integration with external BI tools and custom dashboards. Resellers who have built custom reporting solutions on the 3CX API should review the updated API documentation.
Update Process: What Resellers Need to Know
Updating 3CX V20 instances to Update 2 is straightforward for cloud-hosted deployments but requires attention to timing and pre-update checks:
Backup first: Always take a full system backup before updating. In 3CX’s management console, this is found under Admin → Backup. The backup file should be stored externally — on the hosting server is insufficient if the update causes a system issue.
Check custom configurations: Customisations to 3CX’s Nginx configuration, custom IVR prompts stored outside the standard directory, and custom email templates can sometimes need re-applying after major updates. Document these customisations before updating.
Schedule maintenance windows: Updates typically take 5–15 minutes and require a brief service interruption. Schedule updates for low-traffic periods — early morning or weekend — and notify clients in advance.
Test after updating: After each update, verify: incoming calls via SIP trunk, internal extension-to-extension calls, mobile app registration, web client login, and call recording. A brief 5-minute post-update check is much better than discovering a problem hours later when the client calls.
V20 Multi-Tenant: Changes in U2
For MSPs running multi-tenant 3CX deployments, V20 U2 introduced improvements to the tenant isolation model and management interface. Key changes:
- Improved tenant provisioning speed — new tenants can be added more quickly from the management portal
- Better resource allocation controls allowing MSPs to limit the CPU and memory usage of individual tenant instances
- Enhanced logging and alerting at the tenant level, making it easier to diagnose issues specific to a single customer without reviewing the entire system log
These improvements make V20’s multi-tenant model more production-ready for MSPs hosting dozens of client instances. Combined with the April 2026 policy enforcement for multi-tenant licensing (minimum 16 SC PRO), V20 U2 represents the most capable and policy-compliant version for MSP use.
Upgrading from V18 to V20
Resellers with clients still running 3CX V18 should be actively planning migrations to V20. 3CX extended support for V18 beyond its original end-of-life date, but V18 is no longer receiving feature updates and will eventually reach end-of-support. Key considerations for V18 to V20 migrations:
Architecture change: V20 uses a different deployment model than V18. In-place upgrades from V18 to V20 are supported but are more complex than a standard version update. Many resellers choose to deploy a fresh V20 instance and migrate the configuration rather than upgrading in place.
Extension app migration: The V20 Windows desktop app and mobile apps are different from V18. Clients will need to uninstall the old apps and install the new ones. On a large deployment this requires user communication and change management support.
SIP trunk re-registration: Some SIP trunk configurations need to be rechecked after the V18 to V20 migration, as V20 handles SIP authentication differently in some edge cases. Test all SIP trunks after migration, not just one.
What This Means for SA Telecoms Resellers
Keeping 3CX deployments current is part of responsible managed service delivery. Clients running outdated versions miss out on security patches, performance improvements, and new features. Building a regular update schedule into your managed service offering — and communicating the benefits of updates to clients — protects both their business and your support relationship.
V20 Update 2 specifically addresses several issues (iOS call reception, web client audio quality) that have been common sources of client complaints. Proactively updating clients experiencing these issues and communicating the fix demonstrates value and reduces support ticket volume.
For resellers managing multiple client instances, consider scripted update workflows that can be applied consistently across all managed customers, reducing the time investment per customer while ensuring uniform version control across your portfolio.
About the Author
Mechelle Gindra
Mechelle Gindra is the managing editor and lead content strategist at Telecoms-Channel, South Africa's dedicated intelligence platform for telecoms resellers, ICT distributors, and channel partners. She oversees the editorial team's AI-assisted content production pipeline, ensuring vendor news, market analysis, and regulatory updates are accurate, timely, and actionable for the SA telecoms channel community. With deep expertise in the South African telecoms reseller ecosystem, Mechelle directs coverage of vendor partner programmes, ICASA regulatory developments, wholesale market dynamics, and channel business strategy. She is responsible for maintaining Telecoms-Channel's editorial standards, fact-checking processes, and corrections policy.
