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zorinlynx

macrumors G3
May 31, 2007
8,353
18,580
Florida, USA
I bit the bullet and upgraded my phone to the beta. Wi-Fi calling is working in Miami, FL!

As a network admin by trade I got curious and did some sniffing around. It seems WiFi calling is implemented using an IPSec tunnel. From what I can tell (it's encrypted, so you can't tell much) it's tunneling IPv6 over your IPv4 WiFi. If you open Network Tools (from Hurricane Electric) you can see that your phone will have a couple of IPSec tunnel interfaces with world routable IPv6 addresses.

Basically, AT&T is doing VoIP in its truest form, giving everyone an IPv6 (whether native on cellular, or through a tunnel when on Wifi) address, and routing calls and text messages over that.

There's a lot going on, and a lot that can go wrong, which is why they are probably rolling it out to beta users first and not to everyone at once. :)
 
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SRLMJ23

macrumors 68020
Jul 11, 2008
2,321
1,421
Central New York
I bit the bullet and upgraded my phone to the beta. Wi-Fi calling is working in Miami, FL!

As a network admin by trade I got curious and did some sniffing around. It seems WiFi calling is implemented using an IPSec tunnel. From what I can tell (it's encrypted, so you can't tell much) it's tunneling IPv6 over your IPv4 WiFi. If you open Network Tools (from Hurricane Electric) you can see that your phone will have a couple of IPSec tunnel interfaces with world routable IPv6 addresses.

Basically, AT&T is doing VoIP in its truest form, giving everyone an IPv6 (whether native on cellular, or through a tunnel when on Wifi) address, and routing calls and text messages over that.

There's a lot going on, and a lot that can go wrong, which is why they are probably rolling it out to beta users first and not to everyone at once. :)


Very interesting! Thanks for explaining that.

:apple:
 

hansenc

macrumors 6502a
Jun 16, 2004
515
197
i've been at 1-2 bars all night @ home and still wont kick in automatically. like others if I turn on airplane mode it does seem to enable and stay enabled till i leave my wifi network.
 

gsmornot

macrumors 68040
Sep 29, 2014
3,672
3,853
That is very odd. I have a Alpine aftermarket system in my car with bluetooth or you can directly connect a iPod and control it all from the Alpine Deck. I do not understand why your bluetooth does that because of wifi?? I walk out to my car and the phone knows so it has Music ready for me and if do bluetooth it works fine or if I switch to the iPod that is directly connected everything is fine. Have you tried resetting network connections and possibly all connections and settings? Something is just not right with the way your phone is handling things. Bluetooth and WiFi are totally different connections so they should not interfere with each other like that. What kind of car/deck do you have? Just trying to help!

:apple:

Thank you. It's cool though, it comes and goes this way with release updates. All was well for a while back on 8.x. It works too if you turn off location services. Wifi is faster since its in the control center. It's strange but I'm not alone. The suggestion to kill wifi on calls came from someone else's discovery.
 

gsmornot

macrumors 68040
Sep 29, 2014
3,672
3,853
i've been at 1-2 bars all night @ home and still wont kick in automatically. like others if I turn on airplane mode it does seem to enable and stay enabled till i leave my wifi network.

1-2 bars are enough for calls so it should stay on cellular. It will use wifi only when you're in conditions for calls to drop or fail all together. (Or it should wait until then)
 

Dominick624

macrumors regular
Feb 10, 2014
103
8
But wouldn't it save battery if it were to simply use wifi calling, rather than keep you on a 1-2 bar connection? Since the phone has to use more power to achieve a better cell signal?
 

gigapocket1

macrumors 68020
Mar 15, 2009
2,410
1,925
Just got mines activated.. Living in Orlando.. Billing is based out of Memphis. Mobile share plan
 

hansenc

macrumors 6502a
Jun 16, 2004
515
197
read online that some phones (guessing android) all you to set a preference of wifi or cellular. is this an option on tmobile wifi
But wouldn't it save battery if it were to simply use wifi calling, rather than keep you on a 1-2 bar connection? Since the phone has to use more power to achieve a better cell signal?

Same thoughts I was having. I saw some Android screenshots that allow you to set priority over one vs. the other.
 

andyw715

macrumors 68000
Oct 25, 2013
1,844
1,404
Yeah it would be nice (in the WiFI settings) to always connect WiFi calling when connected to certain SSIDs
i.e home and work, always connect.

You would think carriers would like this, to get some percentage of handsets off the towers.
 

Harthag

macrumors 68020
Jun 20, 2009
2,015
2,567
U.S.
Would somebody be good enough to post a picture of their screen on WIFI calling.

Here you go.

wifi pic.PNG
 

fireitfox

macrumors newbie
May 24, 2009
26
0
SF Bay Area here, I was able to activate this morning! I have no cell signal at work, and have been using it all morning!

In which city in bay area are you getting wifi calling? I am tried to activate in Fremont, Sunnyvale and Cupertino, i get the message wifi calling is not available in your area.
 

edulinka

macrumors regular
Oct 22, 2012
111
2
Upstate NY
It doesn't matter where you leave. Here from chat with ATT support

WIFI calling has been opened to all markets and requires the setup on this end which we confirmed. The phone must be an iPhone 6 or 6 plus with iOS 9 picking up and picking up and AT&T LTE signal as well.
 

JM3581

macrumors newbie
Apr 27, 2015
12
1
After calling AT&T I was finally able to activate it in Philadelphia. They had my phone number still associated with the IMEI of my old 5s instead of my 6 plus in their system. Once they corrected the IMEI i was able to active it right away.
 

jpsmith76

macrumors regular
Jun 4, 2014
125
211
Huntsville, AL USA
I called At&T and after some checking they said that you have to be in an HD Voice are (Both phone number and physical location) They also verified that my correct phone is listed and that VoLTE is enabled on my account. So, in Huntsville AL with a Birmingham AL number, I will have to wait awhile longer.
 

theshoehorn

macrumors 6502a
Jul 6, 2010
505
490
I called At&T and after some checking they said that you have to be in an HD Voice are (Both phone number and physical location) They also verified that my correct phone is listed and that VoLTE is enabled on my account. So, in Huntsville AL with a Birmingham AL number, I will have to wait awhile longer.
I live in a location with no HDVoice, or was in a location with HDVoice at the time I activated it... So from my experience this is false... But I could be wrong...
 

freeskier93

macrumors 6502
Jul 13, 2008
321
68
I was able to turn on wifi calling earlier this week, initially it didn't seem like it ever switched over but now it seems to always be on wifi calling. I hover between 2 and 3 bars where I live. I don't think it's as simple as bar threshold either, I suspect there is some learning involved (that seems to be the theme of iOS 9 is personalized learning).
 

ericgtr12

macrumors 68000
Mar 19, 2015
1,774
12,175
Since the beta dropped with the new carrier settings profile two weeks ago, my iPhone 6 does not like to lock onto my 3G microcell. It still will, but it does not prefer it like it used to.
Won't WIFI calling negate the need for Microcell, or am I not understanding how it works properly?
 
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