Wi-Fi calling?



  • Just got an notice that said that we have wi-fi calling from our provider.

    Wi-Fi calling? Exactly what is that? Is it consumer-speak for voip?

    I've searched the net and found lots about how to enable it and whatnot, but not much about what it actually is.



  • @Pete-S
    From what I understand it allows the carrier to route your assigned number either over the cell network or via the public internet, depending on what's available and activated on your phone. I can activate it on my Pixel and still get calls and sms via my regular number over the wifi when I'm at the sister-in-law's where cell service sucks.

    So yes, strictly speaking it's voip but in a carrier-managed fail-over type of configuration.



  • @notverypunny is right. I leave it turned on all the time. I find that I am talking on WiFi quite often. It works great when were are in old churches with 36 inch thick stone walls, and there is no chance of cellular connectivity, or three or four flights underground. 🙂



  • @JasGot said in Wi-Fi calling?:

    @notverypunny is right. I leave it turned on all the time. I find that I am talking on WiFi quite often. It works great when were are in old churches with 36 inch thick stone walls, and there is no chance of cellular connectivity, or three or four flights underground. 🙂

    Or just one underground... my office basement is a black whole for signals.



  • @Dashrender said in Wi-Fi calling?:

    @JasGot said in Wi-Fi calling?:

    ...or three or four flights underground. 🙂

    Or just one underground... my office basement is a black whole for signals.

    When I go down, I go all the way down. !



  • I didn't realize that was a carrier-controlled thing. I thought it was 100% device.



  • @Obsolesce said in Wi-Fi calling?:

    I didn't realize that was a carrier-controlled thing. I thought it was 100% device.

    it's both. the device has to support it, AND the carrier has to support it.



  • I use it all the time on my iPhone when I have poor service. Works great for me.



  • So it will work over any wi-fi connection or just the carriers own wi-fi?



  • @Pete-S Should be on any wifi on the condition that there's nothing firewalling the service. We had to open some ports here at work to allow it out on some specific ports



  • @notverypunny said in Wi-Fi calling?:

    @Pete-S Should be on any wifi on the condition that there's nothing firewalling the service. We had to open some ports here at work to allow it out on some specific ports

    Alright, thanks. Do you remember what port(s) it was?

    We have egress filtering on our firewalls. Don't want ET (or malware/bots) phoning home.



  • @Pete-S said in Wi-Fi calling?:

    Wi-Fi calling? Exactly what is that? Is it consumer-speak for voip?

    Yes. It's VoIP generally using your cell number.



  • @Pete-S said in Wi-Fi calling?:

    So it will work over any wi-fi connection or just the carriers own wi-fi?

    I'm not familiar with any carriers offering wifi. The accepted intention is that you can call off of any wifi that you find. Otherwise it wouldn't be useful.



  • @Obsolesce said in Wi-Fi calling?:

    I didn't realize that was a carrier-controlled thing. I thought it was 100% device.

    Essentially all compute devices can do wifi calling. Anything with a wifi connection. But only .01% of them are connected to a carrier that will allow it.

    I can wifi call from my cell phone, but not from my tablet or laptop, but they have all of the technology to do so.



  • @Pete-S I wouldn't be surprised if it varies by carrier but we had to allow udp 500 and 4500 on our egress rules.



  • @scottalanmiller said in Wi-Fi calling?:

    @Obsolesce said in Wi-Fi calling?:

    I didn't realize that was a carrier-controlled thing. I thought it was 100% device.

    Essentially all compute devices can do wifi calling. Anything with a wifi connection. But only .01% of them are connected to a carrier that will allow it.

    I can wifi call from my cell phone, but not from my tablet or laptop, but they have all of the technology to do so.

    You can WiFi call if you install a VOIP client on those devices 😛



  • @Dashrender said in Wi-Fi calling?:

    @scottalanmiller said in Wi-Fi calling?:

    @Obsolesce said in Wi-Fi calling?:

    I didn't realize that was a carrier-controlled thing. I thought it was 100% device.

    Essentially all compute devices can do wifi calling. Anything with a wifi connection. But only .01% of them are connected to a carrier that will allow it.

    I can wifi call from my cell phone, but not from my tablet or laptop, but they have all of the technology to do so.

    You can WiFi call if you install a VOIP client on those devices 😛

    No, you can VoIP Call. WiFi Calling is a specific thing that you can't get a client for.



  • I did some more research and it turns out that WiFi calling is using some familiar protocols but it's not the same as VoIP using SIP/RTP.

    Actually another name for Wi-Fi Calling is the more official VoWiFi.
    It's using a protocol called GAN (Generic Access Network) that is based on IMS, IPsec and ePDG. And IMS is using SIP for signaling.

    Basically it's a way of sending the same packets that would go over the cell network over internet instead. It uses the SIM card for security and authentication. It's data is encapsulated in an IPsec tunnel - which is why it only works if IPsec ports and packets are allowed in the firewall.

    Related technology that works in a very similar way is VoLTE, which is Voice over the 4G/LTE network.



  • @Pete-S said in Wi-Fi calling?:

    I did some more research and it turns out that WiFi calling is using some familiar protocols but it's not the same as VoIP using SIP/RTP.

    Actually another name for Wi-Fi Calling is the more official VoWiFi.
    It's using a protocol called GAN (Generic Access Network) that is based on IMS, IPsec and ePDG. And IMS is using SIP for signaling.

    Basically it's a way of sending the same packets that would go over the cell network over internet instead. It uses the SIM card for security and authentication. It's data is encapsulated in an IPsec tunnel - which is why it only works if IPsec ports and packets are allowed in the firewall.

    Related technology that works in a very similar way is VoLTE, which is Voice over the 4G/LTE network.

    Did you happen to learn if it uses the SS7 network? It would be very intersting if VoWiFi avoided the SS7.



  • @JasGot said in Wi-Fi calling?:

    @Pete-S said in Wi-Fi calling?:

    I did some more research and it turns out that WiFi calling is using some familiar protocols but it's not the same as VoIP using SIP/RTP.

    Actually another name for Wi-Fi Calling is the more official VoWiFi.
    It's using a protocol called GAN (Generic Access Network) that is based on IMS, IPsec and ePDG. And IMS is using SIP for signaling.

    Basically it's a way of sending the same packets that would go over the cell network over internet instead. It uses the SIM card for security and authentication. It's data is encapsulated in an IPsec tunnel - which is why it only works if IPsec ports and packets are allowed in the firewall.

    Related technology that works in a very similar way is VoLTE, which is Voice over the 4G/LTE network.

    Did you happen to learn if it uses the SS7 network? It would be very intersting if VoWiFi avoided the SS7.

    Why do you care? That is a back-haul PSTN network between carriers that you have no access or say about.

    But the correct answer is, "not while the call is a 'Vo' (Voice over) anything." At that point it is traveling over data networks. Which, by definition, cannot be switched telephone signalling.


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