Navigating Teams Voice Connectivity from Vox
The use of Teams Phone, a cloud-based phone system, transforms Microsoft Teams into a full Unified Communications as a Service (UCaaS) platform, blending Voice, video, chat and collaboration. To enable external calling, organisations can select from a variety of solutions, each balancing simplicity, control and customisation.
The right choice for your business depends on your IT maturity, existing infrastructure and business needs.
In this article we discuss the various options of navigating Microsoft Teams Voice Connectivity from Vox. Collectively, our customers report deployments that are 20 to 50 percent faster, with lower operational costs, and resilience tailored to SA’s infrastructure challenges.
Microsoft Teams Voice: Three Excellent Options to Consider
Microsoft Teams offers two primary pathways for enabling public switched telephone network (PSTN) or PSTN-replacement (VoIP) calling from within the Teams application, namely:
- Operator Connect for managed simplicity, and
- Direct Routing for flexible control.
We also discuss:
- Azure Communication Services (ACS), a developer-centric Platform as a Service (PaaS), for building custom communication apps that extend Teams Phone into other IT assets.
The choice for your organisation hinges on factors such as infrastructure, scale and workforce distribution.
In addition, the options aren’t mutually exclusive. For example, you may want or need to use Operator Connect for core users and Azure Communication Services for developer-built bots, or Direct Routing with a Survival Branch Appliance (SBA) for branch offices or sites that can never be without telephony services (for example underground mining).
In short, though, it’s useful to think of your options as follows:
- Operator Connect suits low-overhead rollouts in regulated sectors such as finance, legal and advisory;
- Direct Routing fits legacy-heavy environments such as manufacturing; and
- Azure Communication Services (ACS) is suitable if you’re building custom experiences, for example, Voice in CRM apps, or need extensibility beyond your standard PBX.
Operator Connect (OC)
Operator Connect (OC) is a fully managed service where the Vox Voice network enables calling to and from any destination while being integrated directly into Teams. No on-premises hardware is required – Vox peers with Microsoft’s Azure network for seamless integration.
Key features include the following: Number provisioning via Teams Admin Centre, built-in emergency calling, fraud monitoring, and 99.999% SLA from Vox and Microsoft. OC supports hybrid models (for example: mix with Direct Routing for sites that require offline survivability).
OC is best for organisations prioritising speed and a low IT burden. A deployment can take hours to days, instead of days to weeks, making OC ideal for environments requiring optimal security, fast scaling and low IT burden.
Choose Operator Connect if you are Microsoft 365-centric, want zero hardware (no Session Border Controller appliances – SBCs – or desk phones), and you value the provisioning of managed services with joint Vox-Microsoft support. It’s ideal for cloud-first migrations or when time-to-service in a week or less matters.
Typical industry use-cases include financial services (security, fraud monitoring); higher education or public sector (budget scrutiny, multi-site rollouts); retail and hospitality (high staff churn, thin IT capability across franchises).
Integrations: You could add ACS for AI call summaries and bot-to-human call hand-off.
- Vox example: A Kwa-Zulu Natal university provisioned 2,400 users in days, inheriting Entra ID policies for seamless multi-factor authentication.
Direct Routing (DR)
Direct Routing allows the connection of your existing SIP trunks or PBX to Teams via a Session Border Controller (SBC) appliance. This SBC can be hosted on your premises or in your private cloud, or you can take advantage of Vox’s multi-tenanted SBCs.
With Direct Routing and your own SBC, you retain control over routing and carrier relationships, and with Vox’s shared SBCs we manage routing on your behalf.
Key Features include the following: Advanced call routing (for example failover paths), support for Survivable Branch Appliance (SBA) for local calling during internet outages, and compatibility with legacy endpoints like analogue phones or Digital Enhanced Cordless Telecommunications (DECT.
Direct Routing is best for businesses with complex, on-premises setups needing customisation. DR setup involves more planning, as well as more IT and scripting skills, and deployment is likely to take weeks to months.
Choose Direct Routing if you need on-prem survivability (for example, SBA for internet outages). DR is well suited for complex routing or when full control over media paths is required, due to its granular control over your calling environment.
Typical industry use-cases include manufacturing and utilities organisations (often incorporating legacy DECT/analogue integrations), or logistics and healthcare, which are typically device-dependent, and where offline survivability is critical).
Integrations: You could add an SBA for offline survivability or integrate ACS for custom analytics.
- Vox example: A Cape Town logistics firm retained SIP trunks while routing 80% calls via Teams, using SBAs for depots.
Azure Communication Services (ACS)
Azure Communication Services (ACS) is a developer-centric PaaS for building custom communication apps that extend Teams Phone into other IT assets. It’s not a standalone PBX but integrates for scenarios such as embedded calling in apps or AI-driven interactions.
Key Features include the following: APIs for call recording, transcription, video at 720p+, and interoperability with Teams (for example, joining Teams meetings from custom applications or support platforms).
Azure Communication Services is best for innovators embedding Voice into workflows, such as custom contact centres or mobile apps. ACS pairs well with OC/DR for enhanced features without replacing core telephony services or needs.
Choose Azure Communication Services if you’re building custom experiences (for example, Voice in CRM apps) or need extensibility beyond your standard PBX. ACS’s low-code APIs make it accessible for developers, with pay-as-you-go pricing.
Typical industry use cases include tech or consulting (embedded communications in third party applications); contact centres (CCaaS integrations); finance and healthcare (where secure, compliant bots guide incoming calls, and hand off calls to humans where complexity cannot be handled by a bot).
Integrations: Add Teams Phone for hybrid calls and Copilot for AI transcription.
Choosing the right solution for your organisation does not need to be a one-size-fits-all decision. For example, you could start with Operator Connect for 80 percent coverage, layer in Direct Routing for edge cases, and at a later stage add Azure Communication Services for innovation and automation, thus reducing rip-and-replace risks and costs.
Partner with Vox for your Business Voice Requirements
Teams Voice options empower South African businesses to future-proof their communications without necessarily overhauling existing ecosystems. Your organisation could deploy Operator Connect for effortless deployment and scale, Direct Routing for control, and ACS for innovation.
Microsoft-centric organisations in regulated or distributed verticals often see 30 to 50 percent efficiency gains from hybrid deployments, while legacy-heavy setups thrive on Direct Routing.
As your local certified partner, Vox demystifies the realities of Business Voice to match your reality. Vox will engage with you in an initial consultation that covers the following points within this practical evaluation checklist:
- Infrastructure Audit to ensure highest return on current investments;
- Scale and speed requirements;
- Compliance and resilience needs;
- Customisation requirements;
- Integration path needs; and
- A total cost of ownership review that factors in hidden costs.
Explore a no-obligation assessment at https://www.vox.co.za/microsoft-operator-connect/.
Frequently Asked Questions
What is the difference between Operator Connect and Direct Routing?
Operator Connect is a managed service where Vox provisions calling directly into Teams with no SBC required by you. Direct Routing connects your SIP trunks or PBX to Teams via an SBC that you host, giving you more control and customisation.
Can I mix Operator Connect and Direct Routing?
Yes. Many organisations use Operator Connect for core users and Direct Routing for specific sites or legacy integrations where survivability or specialised routing is required.
Do I need on‑premises hardware for Teams Phone?
Not if you choose Operator Connect. The SBCs are hosted by Vox and each user can use either their laptop or mobile device as an endpoint.
What is Azure Communication Services (ACS) used for?
ACS is for developers building bespoke voice/video features or embedding calling into apps and CRM systems. It is not in itself a Teams calling solution, but complements OC/DR rather than replaces them.
How does survivability work if the internet fails?
Direct Routing can be paired with a Survivable Branch Appliance (SBA) to provide local onsite calling if internet connectivity is lost. Operator Connect relies on cloud availability and can be paired with hybrid designs for resilience.
How long does deployment take?
Deployments vary: Operator Connect implementations can be hours to days for typical rollouts; Direct Routing projects often take weeks to months depending on complexity.
Will Vox support compliance and fraud monitoring?
Yes. Vox provides fraud monitoring and supports emergency calling compliance. We’ll include these requirements in the assessment.
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