11 Replies Latest reply: Oct 22, 2014 6:49 AM by pavman RSS

    iPhone 6 (and 5s) running very hot when wifi calling is enabled and on wifi

      Right away the 1st day I received my iPhone 6 and turned on the wifi calling while on my home wifi, my phone got REALLY warm - more like hot.  I was NOT making any wifi calls, just using the phone while on wifi with the calling enabled.   Then I took a trip to Chicago where I was never able to get on any local wifi so the temperature stayed w/in reason (charging/heavy use).   Then when I got back home yesterday evening, and right away when I got to using the phone while on wifi (again, not calling) - it got really hot.

       

      Then this morning I upgraded my wifi's 5s to iOS 8.0.2 so she can use the wifi calling.  DITTO right away with normal use and wifi calling JUST enabled, it got hot.  She couldn't even put the phone in a pocket and resting there as it was too hot.  We turned off the wifi calling and then under normal use, temp seemed normal - didn't get to hot.

       

      This seems to be an issue with iPhone's that have wifi calling enabled - yet not even in current use (make calls over wifi).

       

      Moving to Tmo reason number 1 = wifi calling as my home as is a Tmo blackhole.  Hope this gets resolved.  I looked all over the 'net and couldn't come up with any others talking about it, seems strange.

        • 1. Re: iPhone 6 (and 5s) running very hot when wifi calling is enabled and on wifi

          I am having the exact same symptoms/issue. I did a lot of network debugging/etc and will paste in my previous posts from the Apple forum below. Today I also tried switching to a 3gg sim (tech support confirmed I was on a 3g sim), but this did not seem to be any improvement.

           

           

          Original post:

           

          I switched to T-Mobile with the release of the iPhone 6, but have been having some issues with Wifi Calling.

           

          The main issues are:

          1) Incoming calls often don't ring the phone (tested in various scenarios)

          2) Phone noticeably warm when wifi calling is enabled

          3) Carrier name at the top switches between "Tmobile Wifi" and "Tmobile" often

           

          I have done some network debugging and have a bit of insight into why we are seeing this, but no solution. It appears the iphone makes a VPN connection (IPSec) to T-Mobile somewhere in the 208.54.0.0/16 network range. This is presumably to carry the call/sms traffic securely over whatever connection you are using. Here is a partial dump of the handshake/authentication:

           

          13:40:53.455370 IP 192.168.1.50.500 > 208.54.73.75.500: isakmp: parent_sa ikev2_init[I]

          13:40:53.530091 IP 208.54.73.75.500 > 192.168.1.50.500: isakmp: parent_sa ikev2_init[R]

          13:40:53.566009 IP 192.168.1.50.4500 > 208.54.73.75.4500: NONESP-encap: isakmp: child_sa  ikev2_auth[I]

          13:40:53.978595 IP 208.54.73.75.4500 > 192.168.1.50.4500: NONESP-encap: isakmp: child_sa  ikev2_auth[R]

          13:40:53.978600 IP 208.54.73.75 > 192.168.1.50: ip-proto-17

          13:40:53.978604 IP 208.54.73.75 > 192.168.1.50: ip-proto-17

          13:40:54.417070 IP 192.168.1.50.4500 > 208.54.73.75.4500: NONESP-encap: isakmp: child_sa  ikev2_auth[I]

          13:40:54.780110 IP 208.54.73.75.4500 > 192.168.1.50.4500: NONESP-encap: isakmp: child_sa  ikev2_auth[R]

          13:40:54.799109 IP 192.168.1.50.4500 > 208.54.73.75.4500: NONESP-encap: isakmp: child_sa  ikev2_auth[I]

          13:40:54.931454 IP 208.54.73.75.4500 > 192.168.1.50.4500: NONESP-encap: isakmp: child_sa  ikev2_auth[R]

          13:40:54.936568 IP 208.54.73.75.4500 > 192.168.1.50.4500: UDP-encap: ESP(spi=0x0c3765bd,seq=0x1), length 148

          13:40:54.989651 IP 192.168.1.50.4500 > 208.54.73.75.4500: UDP-encap: ESP(spi=0x003c7a39,seq=0x1), length 1236192.168.1.50

           

          When the phone is put to sleep, it continues to maintain contact with T-Mobile via an isakmp-nat-keep-alive packet (UDP) approx every 20-30 seconds:

           

          13:43:51.901446 IP 192.168.1.50.4500 > 208.54.73.75.4500: isakmp-nat-keep-alive

          13:44:18.494643 IP 192.168.1.50.4500 > 208.54.73.75.4500: isakmp-nat-keep-alive

           

          (side note, this doesn't appear to fully wake the wifi radio, as the phone is still unpingable when these packets are seen)

           

          Unfortuantely at some point (asleep or awake doesn't seem to matter) this happens:

           

          13:45:31.425096 IP 208.54.73.75.4500 > 192.168.1.50.4500: NONESP-encap: isakmp: parent_sa inf2

          13:45:31.427986 IP 192.168.1.50 > 208.54.73.75: ICMP 192.168.1.50 udp port 4500 unreachable, length 36

          13:45:36.425307 IP 208.54.73.75.4500 > 192.168.1.50.4500: NONESP-encap: isakmp: parent_sa inf2

          13:45:36.597782 IP 192.168.1.50 > 208.54.73.75: ICMP 192.168.1.50 udp port 4500 unreachable, length 36

          13:45:41.424608 IP 208.54.73.75.4500 > 192.168.1.50.4500: NONESP-encap: isakmp: parent_sa inf2

          13:45:41.508620 IP 192.168.1.50 > 208.54.73.75: ICMP 192.168.1.50 udp port 4500 unreachable, length 36

           

          It appears the iphone is saying that port 4500 is no longer reachable, forcing the reauthentication of the vpn. The vpn seems to be torn down and restarted over and over, which probably accounts for the heat. It is doing a fair bit of compute work to start the encryption (assumption).

           

          Unfortunately when the vpn enters this state, T-Mobile's backend seems to think it is still connected and doesn't attempt to ring the phone via the cellular network as seen here:

           

          13:48:58.451378 IP 208.54.73.78.4500 > 192.168.1.50.4500: UDP-encap: ESP(spi=0x06d483b4,seq=0x21), length 132

          13:49:01.523505 IP 208.54.73.78.4500 > 192.168.1.50.4500: UDP-encap: ESP(spi=0x06d483b4,seq=0x22), length 132

          13:49:01.871629 IP 208.54.73.78.4500 > 192.168.1.50.4500: UDP-encap: ESP(spi=0x06d483b4,seq=0x23), length 132

          13:49:03.837764 IP 208.54.73.78.4500 > 192.168.1.50.4500: NONESP-encap: isakmp: parent_sa inf2

          13:49:03.882334 IP 192.168.1.50 > 208.54.73.78: ICMP 192.168.1.50 udp port 4500 unreachable, length 36

          13:49:08.836944 IP 208.54.73.78.4500 > 192.168.1.50.4500: NONESP-encap: isakmp: parent_sa inf2

          13:49:08.930204 IP 192.168.1.50 > 208.54.73.78: ICMP 192.168.1.50 udp port 4500 unreachable, length 36

           

          In this case, T-Mobile's server tries to contact me back but fails because the iPhone is no longer interested in chatting on UDP/4500. This leads me to believe the fault is no on T-Mobile's end, but Apple's.

           

          I have done a lot of debugging here, including forcing egress/ingress ports, but in every case the iPhone eventually sends an ICMP port unreachable regarding 4500. I also switched routers during testing and am currently using the T-Mobile Cellspot router. I have also done this testing with two separate iPhone 6s.

           

          This was a lot of annoying debugging, but from this I firmly believe that either 1) T-Mobile and Apple are a bit out of sync on how this vpn should operate. 2) something about iOS sleep state breaks the behind-the-scenes IPSec implementation running on the phone. 3) No idea.

           

          Please fix this Apple. The feature is great, especially when in a location with subpar service. In its current state it drains the battery very quickly and is basically unusable.

          • 2. Re: iPhone 6 (and 5s) running very hot when wifi calling is enabled and on wifi
            mansinha

            You have done more detective work than I have been able to come up with. I tried to use Wifi calling and it promptly stopped me from being able to receive inbound calls. This persisted even after I turned off Wifi calling. Only a reset of the phone with reloading my data from iTunes solved the issue.

            I guessed it may be shutting off a port and your analysis confirms it.

            I have spoken to T Mobile support who said that they would take it up with their Apple counterparts.

            There is a discussion on the Apple forums where someone has approached Apple and is working with their engineers.

            If you have the bandwidth - contacting Apple may help.

            • 3. Re: iPhone 6 (and 5s) running very hot when wifi calling is enabled and on wifi

              Turn it off, it will kill your battery!  Unless you are traveling internationally or out of network it is not worth the bother, until they first realize that this is a problem.

               

              Wi-fi calling is fill of bugs as with Apple's Wi-fi drivers.  If you happen to connect to a 802.11 "G" router you will be able to watch your battery drain at 45% per hour. 

               

              I spent hours dealing with this issue with the idiots at the genius bar telling me to re install my apps.  I think Apple is sending their Geniuses to India to train.

              • 4. Re: iPhone 6 (and 5s) running very hot when wifi calling is enabled and on wifi

                New T-Mobile customer and I just noticed the problem as well.  Got my iPhone 6 on Thursday and the phone has been running really hot, with the battery draining very fast.  Shut off WiFi calling, problem goes away.  Turn it on, problem comes right back.  Not quite sure what to do...

                • 5. Re: iPhone 6 (and 5s) running very hot when wifi calling is enabled and on wifi
                  mansinha

                  HI

                  do you lose the ability to receive calls while on WiFi?

                  if so does this return when you shut off WiFi calling?

                   

                  I had to completely reinstall iOS 8 via iTunes to make my phone able to receive calls.

                  Thank you.

                  • 6. Re: iPhone 6 (and 5s) running very hot when wifi calling is enabled and on wifi

                    No, so far it appears that the WiFi calling feature works, it just makes the phone hot and the battery die quickly. 

                    • 7. Re: iPhone 6 (and 5s) running very hot when wifi calling is enabled and on wifi

                      We definitely want you to be able to enjoy your WiFi calling experience bjkqaz It isn't unusual for the devices to heat up while using WiFi calling. There are no known issues with what you've described for either device. Is the heat the only issue you're experiencing with the phones or are you getting error messages? Have you reached out to Official Apple Support?

                      • 8. Re: iPhone 6 (and 5s) running very hot when wifi calling is enabled and on wifi

                        I have reached out to their support and even spent 3 hours in their "dummy bar" they analyzed my phone and told me that my home screen was using all of my battery and I need to keep the phone turned off if I wanted the phone to last more than  two and a half hours.  I was then told if I did not like it I could take it back to T-mobile.

                         

                        This is CLEARLY an issue and neither T-Mobile nor Apple is willing to accept the problem or address the issue.

                         

                        How about this:  "I am sorry to hear your are having issues with your iphone, it certainly should not heat up and battery die while sitting idle for two and a half hours.  Lets either get you another phone to see if the issue persists or we will send an engineer to your location since we are incapable of seeing anything here and we will try and determine if the Apple product is defective or if it is our T-Mobile wi-fi calling protocol that is causing your issue, as well as others whom are apparently having the same problem"

                         

                        Or would that be just called customer service?

                         

                        With Wi-Fi calling off my iphone 6 works fine,  If you search apple's support site there are many others having the same issue, it may not be very widely reported yet as perhaps most person have not tried this feature. You all can either choose to get in front of this issue or wait till it becomes a bigger problem. 

                        • 9. Re: iPhone 6 (and 5s) running very hot when wifi calling is enabled and on wifi
                          mansinha

                          I agree with you - I think this is an Apple issue as it has not been reported with other WiFi capable handsets. I would advise you - as I am - to keep up with the Apple forums - pressure on them may produce a result - I do not know how much T Mobile can help here frankly

                          • 10. Re: iPhone 6 (and 5s) running very hot when wifi calling is enabled and on wifi
                            tforce_jennifer

                            Hi bjkqaz!  After doing some research, I was still unable to find known issues for what you are experiencing.  I did find some basic troubleshooting for if your device is giving off excessive heat.  It states it's for Android devices, but the same process will be use when we are troubleshooting Apple devices. The specified item was not found.

                             

                            I hope this helps.  Please keep us updated on what's going on?

                            • 11. Re: iPhone 6 (and 5s) running very hot when wifi calling is enabled and on wifi

                              IOS 8.1 update - 21 October 2014

                               

                              This update did not resolve the WiFi issues on the iphone 6.  The 802.11 "G" protocol is still broken and largely unusable.

                               

                              Keep trying apple / t-mobile