Voice Calling Features: VoLTE & VoWiFi (Wifi Calls)

Purpose

This explains the voice calling features available to CommsMobile customers — Voice over LTE (VoLTE) and Voice over Wi-Fi (VoWiFi) — and how to configure, troubleshoot, and escalate issues with them.

These technologies improve voice quality and call setup, and keep calls working where mobile coverage is weak. VoWiFi can also be used overseas to make and receive Australian domestic calls over Wi-Fi as if in Australia; international dialling (IDD) is not supported over VoWiFi.

1. Overview of Calling Technologies

VoLTE (Voice over LTE) runs voice calls over the 4G network, improving clarity and setup speed while keeping data active during calls.
VoWiFi (Voice over Wi-Fi) places and receives calls over an available Wi-Fi network when mobile signal is weak or unavailable.
CommsMobile supports both VoLTE and VoWiFi on compatible postpaid services and approved handsets.
With both enabled, the handset moves between mobile and Wi-Fi as conditions allow.

2. Customer Use Cases

Indoor or low-coverage areas: VoWiFi provides stable calling via home or office Wi-Fi.
Seamless transition: calls move between VoLTE and VoWiFi when both are active.
Travel: customers overseas can use VoWiFi to call Australian numbers as if in Australia.
Poor 4G coverage: enable VoWiFi for consistent call performance.

3. Device Configuration Guide

Apple (iPhone):

Ensure the latest iOS and carrier settings are installed.
Insert the CommsMobile SIM and wait for network registration.
Go to Settings › Mobile Data › Mobile Data Options › Voice & Data and enable VoLTE On.
For Wi-Fi Calling, go to Settings › Phone › Wi-Fi Calling and turn Wi-Fi Calling on This iPhone to ON; accept any prompts.
Confirm Wi-Fi connectivity and test calling.

Android (general steps):

Settings › Connections › Mobile Networks — enable VoLTE Calls.
Settings › Connections › Wi-Fi Calling — enable Wi-Fi Calling.
Choose Wi-Fi Preferred mode if available.
Confirm the device has internet access via Wi-Fi.

4. Common Issues & Fixes

Symptom	Possible cause	Recommended action
Wi-Fi Calling option missing	Device not approved or not VoWiFi-capable	Confirm handset compatibility with the Telstra Wholesale Device Checker — see Check if a Device Works on CommsMobile.
Calls drop on transition	Weak Wi-Fi or LTE signal	Keep both VoLTE and VoWiFi enabled; use strong Wi-Fi.
Calls fail on Wi-Fi	Wi-Fi network blocking SIP/IPSec ports	Test on another Wi-Fi connection or a mobile hotspot.
No VoLTE option	3G-only handset or non-AU firmware	Verify the device supports 4G bands and VoLTE for Australia.
Call setup delay	Outdated software or carrier bundle	Update the OS and restart the device.

5. Partner Checklist Before Escalation

Verify all items before raising a support ticket:

Device supports VoLTE and VoWiFi (Australian variant).
Active CommsMobile postpaid SIM.
Latest software and carrier updates.
Both VoLTE and Wi-Fi Calling enabled.
Tested on an alternate Wi-Fi (if relevant).
Coverage verified on the CommsMobile Coverage Map (not required for calls over Wi-Fi).
Network status checked via the Telstra Outages tool (not required for calls over Wi-Fi).

6. Escalation to Comms Channel Support

If the issue persists after the checklist, raise a ticket with:

Customer name and service number.
Handset make / model / software version.
Detailed symptoms and error messages.
Whether the fault affects VoLTE, VoWiFi, or both.
Troubleshooting steps performed and test results.

Our support team will review and engage network engineering as required.

7. Additional Notes for Partners

VoWiFi can be used overseas to call Australian numbers; these are treated as local domestic calls.
International dialling (IDD) is not supported over VoWiFi.
Emergency calls placed over VoWiFi while abroad route to Australian emergency services.
Ask the customer about their main usage locations (home, work, travel routes) and check those on the CommsMobile Coverage Map before onboarding, to reduce early port-outs due to coverage differences.