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ddcheng's profile

Tutor

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7 Messages

Wed, Nov 23, 2022 5:15 PM

Dual SIM: Cellular data on one, WiFi calling over cellular on second while traveling

I have an iPhone 14 Pro running IOS 16.x, and I am trying to figure out if it is possible to use WiFi calling over cellular while traveling overseas if I have a second eSIM with international data.  I was recently on a trip, and I thought I had everything set up (e.g., no roaming on the iPhone, disabling "International Day Pass" and "Pay Per Use" in the AT&T account), but when I landed, it appeared that my AT&T line still connected to the local cellular provider and never switched over the WiFi calling over cellular.

One thing that I tried to do while I was traveling was to select one of the providers instead of using "Automatic" under Options > Cellular > Network Selection. When I did this and traveled to another country, I did see that WiFi calling over cellular was enabled, but it was for the previous provider that I selected, not AT&T.

I get a similar screen when I am in the US when I am in an area without AT&T coverage, so I thought that it would automatically do that when I was traveling.

In any event, it seems that I could accomplish what I need if I were able to manually select the AT&T network before I leave the US, but I do not seem to be able to do that.  I can do that with another carrier in the same iPhone, so I'm wondering if there is a way to force this option to be available to me while in the US.  Or am I missing some other option either in my account or iPhone?

Accepted Solution

Official Solution

Fl_retire

ACE - Professor

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2.7K Messages

9 days ago

@ddcheng When you have two eSIMs installed you can turn on/off either one as needed.  I had an Italian eSIM for data/voice and AT&T eSIM for Wi-Fi calling.  I had data roaming turned off and in airplane mode prior to leaving US and turned on when Italian eSIM installed. Once I had the Italian eSIM working I turned off the AT&T eSIM. When I wanted to make a Wi-FI call back to the US, I turned off the Italian SIM and turn on the AT&T SIM.  When finished turned off the AT&T SIM.  You have the capability to select which eSIM for data or voice and turn off either as needed.  Never used my International Day Pass (IDP) with my AT&T eSIM making calls back to the US. 

ATTHelp

Community Support

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203.9K Messages

10 days ago

We are here to help with your Wi-Fi calling concerns while overseas, @ddcheng.

 

We do understand how important it is to be able to stay in contact with traveling overseas. 

 

Wi-Fi Calling lets you talk and text from indoor locations where it’s hard even for a strong cellular signal to reach. Wi-Fi Calling can be used in the Domestic Coverage Area (U.S., Puerto Rico, and U.S. Virgin Islands) and from most international countries.

 

You are not able to select the carrier you would like to connect to prior to traveling as you are connected to AT&T's network.

 

To view available carriers while visiting a different country:

  1. Go to the Setting Icon App.
  2. Select Cellular.
  3. Turn off or on the Cellular Data Options.
  4. Then select the Data Roaming Switch to turn it on or off. This will allow the device to attach to foreign wireless network signals when available.

If you are having trouble with Wi-Fi and Wi-Fi calling, you may visit our Wireless Support for step by step troubleshooting while overseas. Go to Fix My Wireless > Connection > Internet > Wi-Fi. 

 
 
You may also contact our International Support Team for further assistance while you are traveling at +1.314.925.6925 Available 24/7 FREE from mobile phone.
 
We hope this helps. Thank you for contacting AT&T Community Forums. We are here if you have any other questions. 
 
Clarissa, AT&T Community Specialist 

Tutor

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7 Messages

10 days ago

Thanks for the reply and the confirmation that I will not be able to select a carrier while I am in the US.  I wish that would be different.

As a follow-up question, is it possible to completely disable data and cause the AT&T line to NOT connect to any foreign network?  I tried to disable "International Day Pass" and "Pay Per Use" in the AT&T account, but when I traveled to another country, I received a message that the International Day Pass was added to my account again as a service.  As a result, it appeared that my AT&T line connected to the foreign network.  To be clear, I wasn't charged, but I was connected, so the AT&T line did not switch to WiFi calling over cellular.

If I disable data for the line, will that cause the line to not connect to the foreign network at all?  I didn't want to do that because the setting for that seemed to imply that it would be in place until the end of the billing period.  Can I disable data in my AT&T account settings then re-enable data if I returned to the US before the billing period ended?

ATTHelp

Community Support

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203.9K Messages

10 days ago

We appreciate your response, @ddcheng.

 

If you're not wanting your device to connect to data while traveling internationally, we'd highly advise for you to disable the data on your device. This means your device won't automatically connect to any foreign networks while abroad. 

 

To turn off wireless data: 

  1. Go to your wireless data usage.
  2. Scroll to Usage options and select Manage data.
  3. Turn data Off or On for the devices you want to manage.
  4. Select Save.

Once returned to the U.S., you'll have the option to turn the data back on. Authorized account users may suspend data for each device on the plan. When data is turned off for a device, it: 

  • Remains off until the end of the current billing period, unless it is turned back on.
  • Will have data reactivated at the start of the next billing period.
  • Can still connect to Wi-Fi.
  • Won’t use data from shared plans.
  • Still has monthly charges.

We hope this answers your questions and feel free to reach back out if you have any further concerns. 

 

Thanks for contacting the AT&T Community Forums.

 

Lynn, AT&T Community Specialist

 

Tutor

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7 Messages

8 days ago

Thanks for the replies.  I don't think they quite get what I want, but it may be a limitation with IOS or something else.  Basically, I want to be able to have the phone use WiFi CALLING over Cellular using the other SIM.  I have seen this in the US when I have been in areas without AT&T coverage, so I know it's possible.  I know how to stop the AT&T SIM from connecting to international data, so I'm not too worried about that, but I would like to be able to use voice calling over WiFi without having to connect to an actual WiFi network.  Again, I know this is possible since IOS 13 when there is a dual SIM in use.

I also understand the workaround of disabling the different carriers when I want to make a WiFi call (thank you, Fl_retire!), but I would like to be able to do that when I'm not actually connected to WiFi.  It's kind of a corner case, so maybe it's not well documented.

I THINK being able to manually select the AT&T network prior to leaving the US would accomplish what I want, but that does not appear to be an option.  I know other carriers provide that option in IOS, so that leads me to believe that AT&T has their network setup so that it's not an option (and that does appear to be confirmed in ATTHelp's first message).

ATTHelp

Community Support

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203.9K Messages

8 days ago

Hello ddcheng, we're here to help you with your network concerns.

Let's meet in a Direct Message to discuss your concerns . Please check your Direct Message inbox (it's the chat icon next to the bell icon in the upper right corner of the forums).

Looking forward to speaking with you soon.

Carlton, AT&T Community Specialist
Fl_retire

ACE - Professor

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2.7K Messages

8 days ago

@ddcheng There is no such thing as Wi-Fi calling over cellular. You either have a cellular or Wi-Fi connection. When I was making a Wi-Fi call at my hotel in Italy it was displaying AT&T with the Wi-Fi symbol so I was making a call without incurring the IDP daily fee with my AT&T SIM on and local SIM off  Once you leave the US and connect to a foreign carrier with the AT&T SIM active it will display the carrier that AT&T roaming agreement is with. 

(edited)

Tutor

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7 Messages

8 days ago

@Fl_retire As of IOS 13, it is possible to use WiFi calling over cellular.  It's a bit of a misnomer because it's not really WiFi calling.  Perhaps I'm using the wrong term, but the gist of it is as follows:

 - AT&T network has WiFI calling enabled (this is why I've been calling it WiFI calling over cellular because it does not work if WiFI calling is not enabled)

 - iPhone has dual SIM

 - iPhone is NOT connected to WiFi

If you enter an area where AT&T has no coverage but the other provider has coverage, the other provider will be connected, and the AT&T line will show "AT&T using cellular data".  I have seen this in rare instances in the US.

All that being said, I am intrigued when you say that your phone was showing the foreign carrier with WiFi calling.  My recollection (and I could easily be remembering incorrectly) is that when I was not connected to WiFi, my iPhone would show a connection to the foreign carrier, but when I was connected to WiFi, it would show the AT&T Wi-Fi symbol.  That difference is what made me think that I was not getting the results that I wanted.  Perhaps I need to travel again!  :)

Fl_retire

ACE - Professor

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2.7K Messages

8 days ago

@ddcheng You  could be correct on the AT&T Wi-Fi display when the AT&T SIM is turn on and connected to a Wi-Fi connection. If the AT&T SIM is on overseas and connected to cellular apps may try to refresh data like a weather app, email, Twitter. This is why I have the SIM off as to not incur the IDP charge. 

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