China SIP Trunk: Private SIP vs Public SIP

In China, government telecom providers offer SIP trunks in two distinct models: Private SIP and Public SIP. Each has its own architecture, security level, and installation requirements.

In this guide

1. Introduction 2. Comparison Diagram 3. Feature Comparison
Last updated: August 2026

Table of Contents

  1. Introduction
  2. Private vs Public Diagram
  3. Feature Comparison Table

In China, local government telecom providers offer SIP trunks in two types: Private and Public.

Private SIP Trunk is more secure because the connection is internal.

Public SIP is easy to use because it connects through the internet.

Private SIP Trunk vs Public SIP Trunk

Private SIP Trunk vs Public SIP Trunk comparison diagram showing internal connection vs internet-based connection in China

Figure 1: Comparison of Private SIP (physical fiber/internal IP) vs Public SIP (internet/SIP credentials).

Walter Wang, CTS Founder

“If you ask me how to choose, I usually start by asking: does your office have a fixed public IP? If not, you’ll most likely have to go with public SIP. Over 20 years, I’ve seen too many companies choose public SIP for ‘convenience,’ only to find they couldn’t connect, and then come back to us for a redesign.”

— Walter Wang, Founder & CEO, CTS China VOIP Consulting

Private SIP Trunk vs Cloud SIP Trunk

Private SIP Trunk

Cloud SIP Trunk
China Service Provider China Telecom, China Unicom, China Mobile China Telecom, China Unicom, China Mobile
Installation address Same city office address as the number application Not required
Server IP format 191.1.x.x Internal IP 47.100.x.x Internet IP
Connection Physical fiber lines connection to local office SIP credentials
IP to IP Connection

Not Sure Which SIP Trunk You Need?

Choosing between Private and Public SIP depends on your security requirements, infrastructure, and business needs. CTS helps you evaluate and implement the right solution for your organization.

📘 How to Get a China SIP Trunk Number — Step-by-step guide

📘 China SIP Trunk Provider Guide — Understand who provides numbers

🔧 Get Your SIP Trunk Service — Start the application process

Not Sure Which SIP Trunk You Need?

CTS helps you choose the right SIP trunk type for your business.

View SIP Trunk Service →