In this guide
1. Introduction 2. Award & Microsoft Partner 3. Part 1: Overall Architecture 4. Part 2: Implementation Details 5. Plans & Pricing 6. Service ScopeTable of Contents
Microsoft Teams / Phone System / Direct Routing
CTS provides Microsoft Teams Direct Routing Phone System in China. We manage the entire lifecycle for you: from number sourcing to SBC hosting and Teams configuration.
Phone numbers in the cloud, Teams SBC in the cloud, full maintenance by CTS.
Top 10 Microsoft Solution Provider 2023
APAC CIO Outlook — 2023
CTS was recognized as a Top 10 Microsoft Solution Provider for our expertise in Teams Direct Routing and unified communications in China. As a certified Microsoft Cloud Solution Provider, we bring deep technical knowledge to every deployment.
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Microsoft Cloud Solution Provider
Part 1: Overall Architecture
1. End-to-End Direct Routing Architecture
The overall architecture of CTS Teams Direct Routing consists of three integrated layers:
Three-Layer Architecture:
1. Top Layer (China City DID Number): CTS connects directly with China Telecom / Unicom / Mobile to secure local numbers under your company's legal entity.
2. Middle Layer (Cloud SBC & SIP Server): Hosted on Alibaba Cloud, the CTS SIP Server and Ribbon SBC bridge the local numbers to Microsoft Teams. This is a fully managed SaaS service with no hardware needed at your office.
3. Bottom Layer (M365 Teams Configuration): CTS provides English-speaking guidance to configure dial plans, voice routing policies, auto attendants, and direct routing within your Microsoft Teams admin center.
2. China Number Options
We offer four distinct models for obtaining numbers for your Teams system. All models ensure 100% legal ownership under your China entity.
Model 1: Fresh New Cloud Number
Apply for a brand new city DID number and host it entirely in the cloud. No hardware is required at your office, and billing is handled through CTS.
Model 2: Keep Old Number — Porting to Cloud
Keep your existing number and migrate it to CTS's cloud SIP server and SBC. This option is subject to carrier approval and may have regional limitations.
Model 3: Keep Old Number — Local Office Gateway
Keep your existing number and physical lines in your local office with a VOIP gateway hardware device. The gateway is isolated from your corporate LAN.
Model 4: Keep Old Number — Internet Data Center (IDC) Gateway
Keep your existing number and move the hardware to a remote data center (IDC) instead of your office. No equipment is required on your premises.
For detailed technical specifications of each model, please refer to our SIP Trunk service page.
3. Cloud SBC Infrastructure
The cloud SBC is the core bridge between China's local telecom network and Microsoft Teams.
Ribbon SBC + Alibaba Cloud: CTS deploys a certified Ribbon SBC on Alibaba Cloud, offering a fully managed SaaS service. You don't need to maintain any hardware in China.
4. Teams Admin Portal Configuration
The final layer of the architecture is the Microsoft Teams Admin Center, where routing rules and policies are applied.
Key Configurations: CTS provides English-speaking guidance for setting up FQDN, dial plans, auto attendants, and voice routing policies in your Microsoft Teams Admin Center.
Part 2: Implementation Details
5. Four Key Elements for Direct Routing
To implement Microsoft Teams Direct Routing in China, four components must be brought together:
1. License: E5 or E3 + Microsoft Phone System License.
2. Certified SBC: Ribbon SBC hosted in China cloud.
3. Public IP & FQDN: Dedicated network and domain for secure connectivity.
4. China Local Phone Number: Provided by CTS via local carriers.
6. Full Solution Scope
CTS manages the entire lifecycle of your Direct Routing deployment, from number application to ongoing maintenance.
What CTS covers: Telecom communication, SIP Server configuration, Cloud SBC setup, Teams license guidance, FQDN & SSL certificate installation, optimized network connection between China Cloud SBC and Microsoft servers, and complete Teams routing policy & dial plan configuration.
7. Model A: Cloud Hosted (New Number)
This deployment model is ideal for companies starting fresh in China, with no existing phone lines to carry over.
- Apply a new local number directly from the telecom provider.
- Host the SIP server and SBC in CTS's Alibaba Cloud infrastructure.
- No hardware required in your office.
Best for: Companies starting fresh in China.
8. Model B: Local Hosted (Keep Current Number)
This deployment model is designed for companies that already have physical phone lines and need to keep their existing numbers.
- Keep your existing physical lines and phone numbers in your local office.
- CTS installs a VOIP Gateway (E1/PSTN) to connect your current lines to the cloud SBC.
- Maintains 100% coverage of all Chinese cities.
Best for: Companies with existing physical lines that need to keep their current numbers.
9. Hybrid Scenario: Centralized Teams SBC for Multiple Offices
For companies with offices in different cities, CTS offers a hybrid approach that centralizes all phone numbers into a single Teams SBC.
How it works:
- Local Office: Keep your existing numbers and physical lines on-premise.
- Cloud Offices: Apply new numbers directly in the cloud.
- Centralized Routing: All office numbers are aggregated into a single cloud SBC, routing directly to your Microsoft Teams tenant.
This simplifies management and reduces infrastructure costs across your entire China operation.
Deployment Plans & Estimated Pricing (USD)
CTS offers two primary deployment models for Teams Direct Routing in China. The table below shows estimated costs in USD. Final pricing may vary based on specific requirements.
What's included in the Consulting & Integration fee?
CTS manages the entire process: communication with the local telecom provider, SIP Server configuration, Cloud SBC (Ribbon) setup, Teams license guidance, FQDN & SSL certificate installation, optimized network connection between China Cloud SBC and Microsoft servers, and complete Teams routing policy & dial plan configuration.
CTS Service Scope for Teams Direct Routing
Related Resources
📘 Operator Connect vs Direct Routing in China — Understand the difference
📘 4 Delivery Models for Teams Direct Routing — Compare your options
🔧 Step-by-Step Direct Routing Setup — Technical guide
📘 Case Study: Cerence Cloud SBC Migration — Real-world example
Ready to Enable Teams Direct Routing in China?
Talk to our senior engineer about your Microsoft Teams voice project.
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