Wi-Fi Offload Network Requirements for Google Fi Wireless

Network configuration requirements to support Wi-Fi offload (Wi-Fi Calling) for Google Fi Wireless devices.

Overview

For Google Fi Wireless devices to successfully use Wi-Fi offload, the local network must meet the requirements below. If any of these are not met, devices may fail to connect calls or data over Wi-Fi even when Wi-Fi signal appears strong.

Requirements

1. Allow required ports and protocols

The network must permit the following ports/protocols originating from wireless clients:

2. Provide DHCP and IP services

The network must provide DHCP and IP services so client devices can obtain a valid IP address automatically.

3. Minimum MTU of 1360 bytes

The network must offer a minimum MTU of 1360 bytes. Traffic below this threshold may be fragmented or fail, degrading call/data quality.

4. No captive portal or traffic redirection

The network must not use a captive portal or otherwise redirect outbound traffic. Captive portals intercept and redirect traffic before a device can authenticate, which blocks Wi-Fi offload from functioning.

Source: Google Fi Wireless Support — Wi-Fi offload network requirements