In this guide
1. About the Service 2. 4 Deployment Models 3. Nationwide Coverage 4. Global Connection 5. Consulting & Application 6. Pricing & Billing 7. Optional Add-onTable of Contents
CTS China SIP Trunk & SIP Trunking Services
CTS focuses on helping enterprises use VOIP in China. We provide local numbers in the cloud, leveraging SaaS architecture to simplify connectivity.
Four Deployment Models to Suit Your Needs
We offer four distinct models to cater to your current infrastructure and requirements. All models ensure 100% legal ownership under your China entity.
1. Fresh New Cloud Number
Apply for a brand new city DID number and host it entirely in the cloud.
- Ideal for: Companies starting fresh in China, or those willing to abandon old numbers.
- Infrastructure: Number hosted in CTS Cloud SIP Server. No hardware required at your office.
- Time to Ready: 1-2 months (mostly waiting for telecom processing).
- Billing: Pay to CTS (postpaid).
2. Keep Old Number — Porting to Cloud
Keep your existing number and migrate it to CTS's cloud SIP server.
- Ideal for: Companies that want to keep their number but prefer a hardware-free cloud solution.
- Infrastructure: Number hosted in CTS Cloud SIP Server. No hardware.
- Limitation: Only supports numbers from specific operators/cities (consult with us).
- Time to Ready: 2-3 months (porting approval required).
- Billing: Pay to CTS (postpaid).
3. Keep Old Number — Local Office Gateway
Keep your existing number and physical lines in your local office with a VOIP gateway hardware device.
- Ideal for: Companies that need 100% China city coverage (especially small cities) and already have physical lines.
- Infrastructure: CTS installs a VOIP Gateway (E1/PSTN) at your office. Isolated from your corporate LAN.
- Time to Ready: 3 days (only onsite installation time).
- Billing: Phone bill paid directly to local provider; CTS service fee paid separately.
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.
- Ideal for: Companies that want to keep the number but don't have physical office space, or prefer remote hosting.
- Infrastructure: CTS installs the gateway in a secure IDC. No equipment in your office.
- Time to Ready: 1-2 weeks (depending on IDC setup).
- Billing: Phone bill paid directly to local provider; CTS service fee + IDC hosting fee paid separately.
Whole China City +86 DID Available
CTS supports 95% of China city DID phone numbers with SIP Trunking.
+8621 Shanghai / +8610 Beijing / +8620 Guangzhou / +86755 Shenzhen / ...
Global SIP Trunk Connection
Customers can set up SIP connections to the CTS China Cloud SIP Server using a public IP, enabling connectivity anywhere in the world.
Trusted by Global Brands
Business & Technical Consulting & Application
Customers sign contracts directly with the telecom provider under CTS consulting. We manage SIP trunk technical setup and troubleshooting.
"Each city and each carrier has different processes and requirements. We've done this in Shanghai, Beijing, Shenzhen, and Chengdu — we've created a dedicated checklist for each set of materials."
Detailed Application Process
Step 1: Pre-review
Time: About 20 days
Materials required:
- Business license
- Bank account license
- Power of attorney
- Photocopy of front and back of ID card of the Person in charge
- Letter of Commitment on Information Security Responsibility
- Purpose of use and speech description
Step 2: Sign Contract
Time: About 20 days
Materials required:
- Formal Watermark Protocol
- Power of attorney
- Account payment certificate
- List of numbers
- Business license
Step 3: Real Name Authentication
Time: About 3 days
Materials required:
- Business license
- Power of attorney
- The person in charge brings their ID card to the business hall for real name authentication
- The operator comes to the business hall for real authentication
Step 4: Set numbers in CTS server
Time: About 3 days
CTS prepares a dedicated cloud server for customers to connect to the operator's number.
Step 5: Number Forward to user
Time: About 3 days
CTS cooperates with the user for debugging numbers.
Note: The information required for each operation pre-examination and contract signing in each region will be different. The above are the most basic, and there will be other materials that need to be supplemented. The process of real name will also be different — some need to go to the business hall, some do not; some staff will come to the door, and some do not need to come to the door.
China SIP Trunk Price and Billing
Direct Payment and Centralized Payment
Customers can pay China Telecom directly, or CTS can pay on behalf of customers with an added service fee.
Optional Add-on: Hosted PBX
If you also need a full-featured cloud phone system, we can bundle it with your SIP trunk as a single solution.
- IVR Voice — Multi-level / on-work / off-work / multiple voice
- Call Recording — Record incoming and outgoing calls in the system
- Conference — Supports phone conference and recording
- 3-way conference — Add a third participant to an ongoing call
- Voice mail — Listen to messages via extension or email attachment
Ask us for details and pricing when you submit your SIP trunk application.