Microsoft Teams Direct Routing vs Calling Plans Explained
Organizations using Microsoft Teams have two main options to enable PSTN calling: Direct Routing (connecting in-country SIP Trunks via an SBC) and Calling Plans (Microsoft-provided phone packages). This guide compares architecture, pricing, features, and trade-offs to help you choose.
Why Connect Teams to PSTN
Microsoft Teams is a collaboration platform combining chat, video, meetings, and files. Teams alone cannot call external PSTN numbers (02, 081). To enable PSTN calling you need a Phone System license plus a "voice path" connection.
Microsoft offers two ways to connect Teams to PSTN: Direct Routing for organizations that want to control the carrier themselves, and Calling Plans for organizations that prefer simplicity by purchasing directly from Microsoft.
What Is Microsoft Teams Direct Routing
Direct Routing connects Teams to in-country carriers using a Microsoft-certified Session Border Controller (SBC). Organizations buy SIP Trunks from a Thai carrier (NT, True, AIS, or a voice provider), then configure the SBC to receive Teams calls and forward them to the carrier.
The advantage is full control: choose your own carrier, reuse existing SIP Trunks, and keep CDR, recordings, and PDPA compliance in your hands.
- Requires a certified SBC (AudioCodes, Ribbon, Oracle, Sangoma, Yeastar)
- Requires SIP Trunks from an in-country carrier
- Requires Microsoft 365 E5 or Microsoft 365 E3 + Teams Phone license
- Supports number porting from existing carriers
- Carrier-side CDR and call recording remain accessible
What Are Microsoft Calling Plans
Calling Plans are PSTN services delivered entirely by Microsoft. Customers buy a monthly package directly from Microsoft and receive numbers from Microsoft (with limited Thai number availability). No SBC or separate SIP Trunk required.
In Thailand, Calling Plans are limited. Microsoft may not provision local 02 numbers in all cases, and per-user pricing tends to be higher than Direct Routing.
- Microsoft acts as the carrier, no SBC needed
- Includes Domestic Calling Plan, International Calling Plan, Pay-As-You-Go
- Higher per-user monthly cost vs Direct Routing
- Limited local number coverage in some countries, including Thailand
- Cannot reuse existing SIP Trunks or carriers
Direct Routing vs Calling Plans Compared
Compare both options across price, features, flexibility, and compliance.
Pricing
Direct Routing: in-country SIP Trunk fees + Microsoft 365 license + SBC cost (hardware or hosted). Domestic per-minute is very low, around 0.50 to 1 THB.
Calling Plans: Microsoft domestic 1,000 or 3,000 minute packages, roughly 8 to 24 USD per user per month.
For organizations with high outbound volume or many users, Direct Routing is usually significantly cheaper.
Features
Direct Routing offers richer features: Survivable Branch Appliance (SBA) for internet outages, analog adapters for fax, paging, and door phones.
Calling Plans prioritize simplicity, but carrier-grade options like caller ID customization or toll-free optimization are limited.
PDPA and Compliance
Direct Routing uses Thai carriers, so CDR and recordings can be stored in-country to meet PDPA requirements.
Calling Plans are managed by Microsoft and may store data in other regions depending on tenant settings.
Deployment
Direct Routing is more complex: SBC setup, voice routing policy, dial plan, typically 1 to 4 weeks.
Calling Plans activate within minutes by purchasing licenses and assigning numbers to users.
Which Fits Which Organization
Choice depends on size, use cases, and existing carrier relationships.
Best Fit for Direct Routing
Organizations already using Thai SIP Trunks, those needing in-country CDR and recording, more than 50 users, requiring varied 02 local numbers, or connecting analog devices (fax, paging) into Teams.
Best Fit for Calling Plans
Smaller organizations with few users, no carrier partner in Thailand, looking for fast deployment without SBC investment.
Required Microsoft 365 Licenses
Both options require a Teams Phone license (included in Microsoft 365 E5 or available as an add-on).
Direct Routing only needs the Teams Phone license, no separate Calling Plan.
Calling Plans need Teams Phone license plus a Microsoft Domestic / International Calling Plan.
Direct Routing Deployment Steps
A typical Direct Routing rollout in Thailand follows six steps.
- 1. Buy SIP Trunks from an in-country carrier
- 2. Install a certified SBC (AudioCodes Mediant, Ribbon SBC, Yeastar P-Series with Direct Routing)
- 3. Configure SBC: SIP profile, TLS certificate, media profile
- 4. Pair the SBC with Microsoft 365 in Teams Admin Center
- 5. Set voice routing policy, PSTN gateway, dial plan
- 6. Assign phone numbers to users and test inbound / outbound calls
Frequently Asked Questions
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