IMPORTANT: This article applies only to specific products and\/or operating systems. Check Applicable Products and Categories<\/em> for details.<\/strong><\/p><\/p>\n\n

What is VoIP?<\/h2>\n\n

Voice over Internet Protocol <\/strong>(VoIP<\/strong>), also known as Voice call over IP<\/strong>, is a SIP (Session Initiation Protocol<\/a>) call technology. VoIP is a communication method which converts analogue voice into digital data packets and sends them over the Internet to make online voice calls.<\/p>\n\n

VoIP calls are not dependent on your operator and don't require a SIM card. All you need is Internet access (Wi-Fi or mobile data), a VoIP app (e.g. Skype) or a VoIP SIP account.<\/p>\n\n

VoIP services are either free or come with a charge:<\/p>\n\n

• You can download applications<\/strong> such as Skype<\/strong>, Viber<\/strong> or WhatsApp<\/strong> to make free online VoIP calls and reach other Skype, Viber or WhatsApp users, respectively.<\/li>
• You can pay a VoIP provider and set up your own VoIP SIP account<\/strong> in your phone. With a SIP account, you can call both mobile and landline numbers.\n\t
  • NOTE<\/strong>: You don’t need a SIP account to use Skype, Viber, WhatsApp etc.<\/li><\/ul>\n\t<\/li><\/ul>\n\n

    What is a VoIP SIP account / SIP Calling? 

    Did you know that you can set up a VoIP SIP account on your phone? It’s like adding a virtual phone system to your mobile device. VoIP phone services can be bought from VoIP providers, and their advantages can often outweigh the costs or save you money. See List of VoIP providers [Wikipedia].

    SIP Calling benefits

    VoIP technology was introduced to address the issues public telephone networks struggled with, such as lack of flexibility or high installation or maintenance costs.

    Here are a few benefits of setting up a VoIP SIP account:

    • You can add a business line to your phone and keep your personal and business calls separate.
    • VoIP can offer the same functionality you’d enjoy when using traditional phone systems (e.g. voicemail, call waiting, call forwarding, caller ID).
    • If you own a business abroad, you can set up a local contact number for your clients. They’re more likely to call a local number than an international number.
    • If you have family abroad, you can save money by setting up a local VoIP number in their country using your SIP account.
    • VoIP plans often include a mobile/desktop VoIP app.
    • The steps to create a SIP account are quite straight-forward, for example:
      1. Choose a plan offered by your VoIP provider (e.g. monthly, annual).
      2. Select a number for your SIP account.
      3. Download your VoIP provider’s app (if applicable).
      4. Link your existing mobile number to your SIP account. 

    Setting up your VoIP SIP account on your Xperia phone

    Note: SIP settings are only available on phones running Android 11 or lower. Please check third-party apps to use SIP [Wikipedia]. 

    To configure SIP calling in your Xperia phone, follow the steps below:

    1. Select Telephone.
    2. Tap the Three-dots icon in the top-right corner of the screen.
    3. Select: Settings → Calling accounts → SIP accounts → “+” (Plus icon). 
    4. Enter your username, password, and SIP server, as shown in the screenshot below.

    

    *You may have to contact your VoIP provider for your SIP account credentials. The settings menu might vary depending on the smartphone model. 

     

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    What is VoWiFi?

    Voice over Wi-Fi (VoWiFi), also known as Wi-Fi Calling, is a Wi-Fi-based commercial telephony voice call service provided by different network operators. Thanks to Wi-Fi Calling you can make and answer calls via a Wi-Fi network instead of using your mobile network.

    • Is your mobile network coverage poor or unavailable?
    • Is your smartphone connected to Wi-Fi?

    If you answered ‘Yes’ both times, Wi-Fi calling might be the perfect solution for you. Wi-Fi Calling can enable or improve your calls in places lacking cellular signal (e.g. an underground basement or a well-insulated building).

    Wi-Fi Calling doesn’t rely on a mobile signal but on a strong Wi-Fi connection. This means you can make Wi-Fi calls when your phone is in Flight Mode when it doesn’t receive a 2G, 3G or 4G signal and even when it doesn’t have a SIM card. However, certain requirements must be met for Wi-Fi calls to work on your phone.

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    Index

    • What do you need to use VoWiFi/Wi-Fi Calling?
    • How do I know if my device and subscription support VoWiFI?
    • What is the difference between VoIP and VoWiFi?
    • Smooth transition between VoWiFi and VoLTE 
    • How do I know if Wi-Fi Calling is working?
    • Does VoWiFi/Wi-Fi Calling offer better call quality? 
    • How much do Wi-Fi calls cost?
    • Can I make emergency calls with VoWiFi?

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    What do you need to use VoWiFi/Wi-Fi Calling?

    Making a VoWiFi call is the same as making a regular call. You don’t need a separate app.  Nevertheless, to use Wi-Fi Calling, the following conditions must be met:

    • Your device’s software is updated to the latest version.
    • Your subscription (including SIM card) must support Wi-Fi Calling for your device model. In other words, your device must be Wi-Fi Calling-capable and compatible.
    • Your mobile must be connected to a (strong) Wi-Fi network.
    • You can’t access the VoWiFi service while travelling abroad.*
    • You need to know the recipient's phone number.

    *Operator-dependant

    How do I know if my device and subscription support VoWiFI?

    • Always contact your mobile network operator to check if your subscription and SIM card support VoWiFi/Wi-Fi calling.
    • Many network operators share lists of devices compatible with VoWiFi on their websites.
    • VoWiFi/Wi-Fi Calling must be turned on in your device’s settings. If your device has the ‘Wi-Fi Calling’ setting, you should be able to toggle the ‘Wi-Fi Calling’ setting On and Off.

    What is the difference between VoIP and VoWiFi?

    • VoIP transfers voice data packets over the Internet to the switched telephone network, while VoWiFi/Wi-Fi Calling reaches your carrier over the Internet instead of a cell tower to establish a phone line.
    • VoIP calls don’t depend on the operator, unlike VoWiFi calls. VoWiFi can only be set up by your mobile network provider, as the set-up authentication process happens in the SIM. 

    Smooth transition between VoWiFi and VoLTE 

    Once VoWiFi is activated on your mobile, your phone will switch to VoWiFi (Wi-Fi Calling) whenever your mobile signal is too weak, but a Wi-Fi connection is present.

    However, if you leave the Wi-Fi range during a Wi-Fi call or if your Wi-Fi connection isn’t strong enough, your smartphone will switch to the mobile network.

    If 4G/LTE* is selected as your phone’s Network mode and you’re within the range of a 4G/LTE network, your phone will automatically switch to VoLTE (Voice over data), and the call will continue. This transition is not possible when calling over Wi-Fi with a separate VoIP app, such as Skype, WhatsApp, etc.

    If VoWiFi doesn’t have VoLTE to fall back to, VoWiFi switches to 3G or 2G, if available. This transition makes the call drop. 

    *The terms 4G and LTE refer to the same technology and can be used interchangeably.

    How do I know if Wi-Fi Calling is working?

    Some mobile operators display a VoWiFi (Wi-Fi Calling) icon on your smartphone’s screen during a Wi-Fi call. Some mobile operators don’t include VoWiFi icons, but there is a simple way to see if you're using this service:

    1. Ensure the VoWiFi settings are enabled in your smartphone, and you’re connected to Wi-Fi.
    2. Disable your mobile data, then try to make a call in an area where you would usually get very poor mobile coverage. If the call quality has improved, you’re using Wi-Fi Calling.

    To check if your subscription and SIM card support VoWiFi/Wi-Fi Calling, contact your mobile network operator.

    Attention: You must enable Wi-Fi Calling manually to use it. Wi-Fi Calling settings don’t get transferred after performing a factory data reset or switching to a different device.