Introducing License Free Calling with ACS Call App
The release of TeamMate version 2.18 includes the latest iteration of our call app, now rebranded ACS Call App. Built on Microsoft’s Azure Communication Services (ACS) Calling SDK, this enhanced Teams app integrates seamlessly with external PBX, UCaaS, or CCaaS systems, delivering robust telephony features without requiring Microsoft Phone System licenses. Here’s how this update transforms unified communications for our customers.
What is the ACS Call App?
The ACS Call App, a fully brand-able add-on to the TeamMate PBX Connector, enables organizations to integrate external PBX (e.g., Avaya, Mitel), UCaaS (e.g., Dialpad), or CCaaS platforms with Microsoft Teams. It leverages ACS’s VoIP infrastructure for crystal-clear voice and video calls, federated with Teams for seamless collaboration.
Key Benefits of the Upgraded ACS Call App
The upgraded app builds on its predecessor’s strengths, delivering even more value. Here’s why it’s a game-changer:
1. No Microsoft Phone System Licenses Required
Microsoft Azure Communication Services (ACS) is a cloud-based platform that enables developers to embed real-time communication features—like voice/video calling, chat, and SMS—into custom applications. The ACS Calling SDK is the component that allows client-side or server-side implementation of these features, such as initiating or receiving VoIP (Voice over IP) calls between users or apps. The TeamMate ACS Call App now fully implements this model by using ACS APIs exclusively, eliminating the need for Phone System licenses ($10/user/month).
2. Effortless Integration with External Systems
Connect your PBX, UCaaS, or CCaaS to Teams in minutes. The app supports SIP federation for VoIP handoffs, enabling external callers to join Teams meetings or channels as native participants. No Direct Routing or Microsoft Teams Phone Resource Accounts are needed post-upgrade, reducing complexity and maintenance overhead.
3. Enhanced Productivity Through Unified Communications
Break communication silos with federated calls (and soon screen sharing and chat). For example, CCaaS agents can see Teams users’ presence and escalate calls to video consults within Teams. Beta users report a significant boost in team productivity due to streamlined workflows and fewer missed calls.
4. Cost-Effective and Scalable
ACS’s pay-as-you-go pricing allows TeamMate to offer the ACS Call App at a significant discount to Microsoft Phone System licensing. The app scales globally with Azure’s infrastructure, maintaining enterprise-grade security (AAD authentication, encryption) and data residency compliance.
5. Future-Proof Compliance
The shift to ACS APIs ensures compliance with Microsoft’s tightened Graph API rules, future-proofing your setup as Teams evolves. The app auto-updates via ACS SDKs, keeping you aligned with Microsoft’s roadmap without manual intervention.
The User Experience
The ACS Call App delivers a native-like Teams experience:
- Seamless Calls: Initiate or receive VoIP calls within Teams with fluent UI components for a polished look.
- Integrated Chat and SMS: TeamMates chat and SMS connectors are now unified into the ACS Cal App, meaning that users can communicate with non-Teams colleagues from a single app within Teams.
- Federated Meetings: External PBX/UCaaS/CCaaS users join Teams meetings via links, with full video, audio, and chat capabilities.
- External Call Control: Server-side workflows handle call queues, transfers, and IVR, perfect for contact centers.
- Notifications: Inbound call alerts appear via Teams system notifications, ensuring you never miss a call.
For example, a financial firm using TeamMate’s app may now connect their UCaaS to Teams, enabling advisors to handle client calls in-channel with zero Phone System licensing costs. Post-upgrade, they’ll enjoy the same functionality without the Graph API dependencies.
What Changes from Prior the Call App?
As described in this prior blog post, the ACS Call App eliminates reliance on Microsoft Graph API transfer bots, ensuring compliance with Microsoft’s new policy (effective September 30, 2025) that requires Phone licenses for bot-initiated call transfers. By transitioning to pure ACS API operations, we maintain full functionality while simplifying setup and reducing costs.
Get Started with TeamMate
The ACS Call App v2.18 is your ticket to unified, license-free communications. Ready to simplify your Teams integration and cut costs? Contact TeamMate Technology for a free demo or proof-of-concept.
