Wi-Fi Calling
The RUCKUS Unleashed Wi-Fi Calling
feature aims to provide better call quality by reducing latency, jitter, and roaming
delays
for voice calls over Wi-Fi.
To achieve this, the RUCKUS Unleashed access point must perform identification, classification, and marking of voice calls when Wi-Fi Calling is enabled and a call is made from a supported client device. Once a call is identified, voice packets are classified and marked to be delivered over an Internet Protocol Security (IPsec) tunnel from the client, through the AP and the controller, and on to the mobile operator's data center.
The Wi-Fi Calling feature provides the following benefits:
- Faster inter-AP roaming using RUCKUS SmartRoam along with standards-based 801.11r/k technologies minimize IPsec session timeouts or teardowns to avoid call drops.
- Voice-aware SmartCast prioritization helps maintain sustained call quality even when there are other clients generating regular Internet packet data.
- A voice call on one SSID will be prioritized in the voice queue over Internet packet data from other SSIDs.
The process consists of the following steps:
- End user turns on Wi-Fi Calling in their smartphone menu, or turns on Wi-Fi and connects to the wireless network.
- Client initiates a DNS lookup to the domain name of the
Evolved Packet Data Gateway (ePDG) (for example, T-Mobile:
ss.epdg.epc.mnc260.mcc310.pub.3gppnetwork.org).
Note: The ePDG on an LTE network acts as an interface between the user device and the non-trusted 3rd Generation Partnership Project (3GPP) access network (for example, Wi-Fi hostpot), providing a security mechanism through a secure IPsec tunnel that is established with the user device.
- Client initiates an Internet Key Exchange version 2 (IKEv2) handshake towards the ePDG to authenticate and set up an IPsec tunnel.
- Client initiates an IPsec session towards the ePDG.
- User is notified that Wi-Fi Calling is activated.
- User initiates a voice call. All voice traffic is tunneled to the ePDG within the IPsec tunnel.