What is the ePDG?
The Evolved Packet Data Gateway (ePDG) serves as a critical bridge between 3GPP networks like LTE and 5G Core and non-3GPP access networks such as WiFi. Acting as a security gateway, it establishes secure connections from untrusted networks directly into the mobile core network infrastructure.
This secure connectivity is achieved through IPsec tunnels, which encrypt and protect all data transmissions from unauthorized access. The ePDG significantly expands the coverage potential and service capabilities of mobile networks.
Key Benefits for Operators
With our ePDG solution, service providers can extend their network coverage cost-effectively, improve accessibility in challenging indoor locations, deliver consistent and seamless connectivity experiences, and enable high-speed ultra-broadband services over WiFi.
How VoWifi Works with ePDG
To offer Voice over WiFi services, operators integrate the ePDG with their Packet Core and IP Multimedia Subsystem (IMS). The system relies on several key components working together:
🔒 IPsec Tunnel
Establishes encrypted connections between user devices and the core network, transparent to the WiFi access point.
🔐 AAA Integration
Authentication, Authorization, and Accounting server validates credentials and protects against cyber threats.
📡 SWu Interface
IPsec-based interface connecting WiFi user equipment to the ePDG, ensuring data integrity and privacy.
⚡ QoS Enforcement
Enforces network policies including Quality of Service parameters for optimal voice performance.
Beyond Voice: Extended Use Cases
While VoWifi is the primary application, our ePDG solution supports numerous additional use cases:
Traffic Offloading
Operators can reduce congestion on their cellular networks by intelligently offloading traffic to WiFi networks. This is particularly valuable in high-traffic environments such as shopping centers, airports, and event venues where WiFi provides a cost-effective way to boost capacity.
Seamless Session Handoff
The ePDG enables uninterrupted session continuity as users move between WiFi and cellular networks. This is critical for applications requiring persistent connectivity like video calls, streaming services, and real-time gaming.
Network Security Services
As a secure gateway, the ePDG can apply security policies and content filtering. Operators can implement parental controls, malware protection, and access management services for subscribers using WiFi networks.
Backhaul Optimization
By leveraging existing WiFi infrastructure, operators can reduce backhaul costs. Data-intensive applications like video streaming can be offloaded to WiFi, optimizing the use of cellular network resources.
Cloud-Native Architecture
Our ePDG solution is fully virtualized and runs as a cloud-native application. This architecture offers several advantages over traditional hardware-based implementations:
- Scalability: Easily scale capacity up or down based on demand
- Cost Efficiency: Reduced capital and operational expenditure compared to dedicated hardware
- Flexibility: Deploy on-premises, in public cloud, or in hybrid configurations
- Integration: Works seamlessly with third-party EPC and 5G Core solutions
Kubernetes-Native Deployment
Like all volte.io solutions, our ePDG is designed for Kubernetes environments. This enables automated operations, simplified upgrades, and seamless integration with modern CI/CD pipelines.
Getting Started
The volte.io ePDG solution is available immediately for operators looking to extend their service coverage with Voice over WiFi. Whether you need a fully managed service or prefer to deploy on your own infrastructure, we offer flexible options to match your requirements.