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Not to take away from your excellent work, but what the hell is the point of VoWifi ? Why not just handle this with a well tuned user space app that runs on ud

Not to take away from your excellent work, but what the hell is the point of VoWifi ? Why not just handle this with a well tuned user space app that runs on udp/whatever over any network connectivity you have already, whether it's wifi/cellular/pigeon carrier. It seems like its an entirely US-centric thing, motivated by a] cost savings from not using data on the cell network (not a problem for most of the world who have unlimited data plans cheap enough for everyone to afford) and b] some kind of vendor feature contest/lock-in type incentives. What is the selling point of it, I don't get it. WhatsApp/Facetime/Signal or similar voice calls are not perfect, they obviously do introduce some extra latency and inefficiencies compared to using that lower level data pipe, but it just strikes me as a very strange avenue for people to be going down with very marginal benefit (efficiency) but a ton of extra work. EDIT: Btw if its not clear, I fully agree with you that it, whatever it is, should be in userspace as much as possible, and as an open standard, I'm just trying to figure out why this stuff has been introduced in this way at all.

wtallis 3y ago
WhatsApp, FaceTime, etc. all require both endpoints of a call to use that app. VoWiFi lets you receive calls to your regular phone number from any normal phone. The fact that the last mile of the call is being carried over WiFi becomes an invisible implementation detail.
- upofadown 3y ago
  The phones could just use the SIP protocol for voice. You don't need an accompanying chat app. The huge disadvantage of that is that the customer could then use any VOIP supplier for their phone calls. ... or none at all for SIP to SIP calls. That would create a competitive market in voice. A competitive market is the last thing any cell phone provider wants. They need to maintain their monopoly on the last mile connection. This might be an interesting idea for a government interested in improving this particular market. Forbid the provision of anything but reasonable latency data by a last mile provider. Establish standards. I note that jmp.chat, a provider of SMS and voice over internet connections, is toying with the idea of providing, pay as you go, data only plans as a complement to their primary service.
  - phh 3y ago
    VoLTE is literally SIP + IPSec + auth with SIM card (+ some pretty usual SIP optional extensions marked as required)
eightysixfour 3y ago
VoWifi is neither US centric nor purely about efficiency - it allows you to make calls with your phone to another phone via a third party network when you don’t have cellular connectivity. For example if you have poor cell coverage at your home or office, you can still make and receive calls via a wifi connection using your phone number instead of forcing everyone to sign up for some third party service.
- lstodd 3y ago
  Well, this sort of reinforces the point - there are about zero places in Europe where you have Wifi but do not have cheap almost-unlimited 4G/LTE. In fact it's wifi that's dying out here, the only thing that keeps it alive is that in a cafe setting it's still somewhat faster, and it eats a bit less battery.
  - eightysixfour 3y ago
    I’m not sure we are talking about the same thing - just because you have cheap unlimited 4G doesn’t mean you get that 4G signal in a basement. VoWifi lets you still call someone with your phone number when the signal is bad but you have wifi access…
    - lstodd 3y ago
      I was never into insisting to only talk on the phone from the basement of my medieval castle. The view from the battlements is much better. We're not all jamesbondesque supervillains here. Like I said above, for like $8/mo you have in fact unlimited 4G at decent speeds here. Or for idk maybe $15 you can get a gpon, unlimited traffic, 30+Mbit to the house, depending on local laziness of course. And that is for a rural place in Balkans, not something in more civilized places.
      - eightysixfour 3y ago
        Yes, and VoWifi lets your cell phone make a call over that fiber when your wireless coverage isn’t great. Not really sure where castles and battlements come to play here - there are plenty of completely normal places people visit with connectivity issues. Maybe it is your experience in the rural balkans, where cellular congestion and significant building density aren’t factors, and your assumption it must be better in “civilized” places that is confusing the issue…
alufers 3y ago
I used to live in an old apartment block with thick concrete walls, and away from a cellular base station. VoWifi was really helpful if I wanted to make calls from my home. I guess I could use WhatsApp/Facetime/Signal, but the insurance agent won't call me on WhatsApp from her landline phone :) And it is not handled by an app on your phone, because of legacy reasons. I believe that, before LTE was introduced, 2G and 3G had a distinction between IP and voice traffic, so the baseband handled the voice transmission. Then they thought that LTE should be IP only and voice should be sent as VOIP over it, but it still had to be handled by the baseband for backwards compatibility with 2G and 3G. And then they came up with the idea that the VOIP traffic could also be piped over Wi-Fi (through the main processor of the phone), and so VoWi-Fi was created.
- numpad0 3y ago
  I think it was lots of parallel development - some mid-to-late 3G phones had carrier hand-rolled Wi-Fi calling, some had femtocell support instead, LTE was to be just faster packet-only Internet mode for 3G, became its own thing too late which necessitated CSFB, and then Wi-Fi calling became reimplemented as part of standard, etc.
- thaumasiotes 3y ago
  > I guess I could use WhatsApp/Facetime/Signal, but the insurance agent won't call me on WhatsApp from her landline phone Huh. I would expect that it's more common for the insurance agent to have WhatsApp (or equivalent) as the only option than it is for them to refuse to use it in favor of the telephone network.
BobbyTables2 3y ago
I think your concerns are misplaced. Things like TCP/IP and DNS are child’s play compared to the complexity of cellular baseband firmware — even for just a single 2G/3G/4G standard. The SIM card layer is also another nightmare in itself.
klausa 3y ago
I can make "regular" phone calls when on a different continent and on WiFi without paying any roaming fees.
yxhuvud 3y ago
> Not to take away from your excellent work, but what the hell is the point of VoWifi ? The point is that your phone should continue to work even if you are deep inside a building without coverage. Or that you should have connectivity if you for some other reason have good wifi coverage but bad cellular. Now, the protocol choices I won't defend, it is layers upon layers of complexity that I don't know enough to understand what is motivated or what is bad.

wtallis 3y ago

WhatsApp, FaceTime, etc. all require both endpoints of a call to use that app. VoWiFi lets you receive calls to your regular phone number from any normal phone. The fact that the last mile of the call is being carried over WiFi becomes an invisible implementation detail.

upofadown 3y ago
The phones could just use the SIP protocol for voice. You don't need an accompanying chat app. The huge disadvantage of that is that the customer could then use any VOIP supplier for their phone calls. ... or none at all for SIP to SIP calls. That would create a competitive market in voice. A competitive market is the last thing any cell phone provider wants. They need to maintain their monopoly on the last mile connection. This might be an interesting idea for a government interested in improving this particular market. Forbid the provision of anything but reasonable latency data by a last mile provider. Establish standards. I note that jmp.chat, a provider of SMS and voice over internet connections, is toying with the idea of providing, pay as you go, data only plans as a complement to their primary service.
- phh 3y ago
  VoLTE is literally SIP + IPSec + auth with SIM card (+ some pretty usual SIP optional extensions marked as required)

eightysixfour 3y ago

VoWifi is neither US centric nor purely about efficiency - it allows you to make calls with your phone to another phone via a third party network when you don’t have cellular connectivity. For example if you have poor cell coverage at your home or office, you can still make and receive calls via a wifi connection using your phone number instead of forcing everyone to sign up for some third party service.

lstodd 3y ago
Well, this sort of reinforces the point - there are about zero places in Europe where you have Wifi but do not have cheap almost-unlimited 4G/LTE. In fact it's wifi that's dying out here, the only thing that keeps it alive is that in a cafe setting it's still somewhat faster, and it eats a bit less battery.
- eightysixfour 3y ago
  I’m not sure we are talking about the same thing - just because you have cheap unlimited 4G doesn’t mean you get that 4G signal in a basement. VoWifi lets you still call someone with your phone number when the signal is bad but you have wifi access…
  - lstodd 3y ago
    I was never into insisting to only talk on the phone from the basement of my medieval castle. The view from the battlements is much better. We're not all jamesbondesque supervillains here. Like I said above, for like $8/mo you have in fact unlimited 4G at decent speeds here. Or for idk maybe $15 you can get a gpon, unlimited traffic, 30+Mbit to the house, depending on local laziness of course. And that is for a rural place in Balkans, not something in more civilized places.
    - eightysixfour 3y ago
      Yes, and VoWifi lets your cell phone make a call over that fiber when your wireless coverage isn’t great. Not really sure where castles and battlements come to play here - there are plenty of completely normal places people visit with connectivity issues. Maybe it is your experience in the rural balkans, where cellular congestion and significant building density aren’t factors, and your assumption it must be better in “civilized” places that is confusing the issue…

alufers 3y ago

I used to live in an old apartment block with thick concrete walls, and away from a cellular base station. VoWifi was really helpful if I wanted to make calls from my home. I guess I could use WhatsApp/Facetime/Signal, but the insurance agent won't call me on WhatsApp from her landline phone :) And it is not handled by an app on your phone, because of legacy reasons. I believe that, before LTE was introduced, 2G and 3G had a distinction between IP and voice traffic, so the baseband handled the voice transmission. Then they thought that LTE should be IP only and voice should be sent as VOIP over it, but it still had to be handled by the baseband for backwards compatibility with 2G and 3G. And then they came up with the idea that the VOIP traffic could also be piped over Wi-Fi (through the main processor of the phone), and so VoWi-Fi was created.

numpad0 3y ago
I think it was lots of parallel development - some mid-to-late 3G phones had carrier hand-rolled Wi-Fi calling, some had femtocell support instead, LTE was to be just faster packet-only Internet mode for 3G, became its own thing too late which necessitated CSFB, and then Wi-Fi calling became reimplemented as part of standard, etc.
thaumasiotes 3y ago
> I guess I could use WhatsApp/Facetime/Signal, but the insurance agent won't call me on WhatsApp from her landline phone Huh. I would expect that it's more common for the insurance agent to have WhatsApp (or equivalent) as the only option than it is for them to refuse to use it in favor of the telephone network.

BobbyTables2 3y ago

I think your concerns are misplaced. Things like TCP/IP and DNS are child’s play compared to the complexity of cellular baseband firmware — even for just a single 2G/3G/4G standard. The SIM card layer is also another nightmare in itself.

klausa 3y ago

I can make "regular" phone calls when on a different continent and on WiFi without paying any roaming fees.

yxhuvud 3y ago

> Not to take away from your excellent work, but what the hell is the point of VoWifi ? The point is that your phone should continue to work even if you are deep inside a building without coverage. Or that you should have connectivity if you for some other reason have good wifi coverage but bad cellular. Now, the protocol choices I won't defend, it is layers upon layers of complexity that I don't know enough to understand what is motivated or what is bad.