AT&T WiFi Call Receiving

[coxhaus]

I am not sure of the right spot so you can move this if it is wrong.

I installed IOS 11.3 on my iPhone 7+ yesterday. It asked if I want to setup AT&T WiFi calling and I did. This falls right in line with my setup of multiple Cisco WAP371 units in my house. I want to test and see if I can switch APs and not drop calls.

On to my question. I have friends which have late AT&T iPhones and they live in the country without cell coverage. Is there a way to setup WiFi calling for receiving calls through their router. If they setup their iPhones for AT&T WiFi calling what needs to change on their router? Do you have to open ports? Do you need to turn on SIP? I have never made any changes for my wife using FaceTime.

 

[CaptainSTX]

I am not sure of the right spot so you can move this if it is wrong.

I installed IOS 11.3 on my iPhone 7+ yesterday. It asked if I want to setup AT&T WiFi calling and I did. This falls right in line with my setup of multiple Cisco WAP371 units in my house. I want to test and see if I can switch APs and not drop calls.

On to my question. I have friends which have late AT&T iPhones and they live in the country without cell coverage. Is there a way to setup WiFi calling for receiving calls through their router. If they setup their iPhones for AT&T WiFi calling what needs to change on their router? Do you have to open ports? Do you need to turn on SIP? I have never made any changes for my wife using FaceTime.

You don't have to change anything on the router to handle WiFi calling. For your friends in the country it is better than nothing but my experience with both T-Mobil and AT&T using WiFi calling has been less than stellar.

What you need to remember is when you leave home is to disable WiFi calling or when you walk into a mall, restraunt, etc with WiFi the phone will try and use it to make a call and it maybe a terrible connection.

The best solution for your friends in the country is to purchase a micro cell from AT&T and plug it directly into their router. It operates as a mini cell tower and up to eight cell phones can be authorized to connect to it. The hand offs between the micro cell and a standard AT&T tower are seamless and your friends don't have to remember to disable the WiFi calling.

 

[coxhaus]

So I guess the iPhones are registering some where outside the firewall otherwise the voice packets will be stopped by the firewall.

Does SIP ALG in the router firewall have any effect on WiFI calling?

 

[OzarkEdge]

So I guess the iPhones are registering some where outside the firewall otherwise the voice packets will be stopped by the firewall.

Does SIP ALG in the router firewall have any effect on WiFI calling?

If it does, like one-way audio, then disable it.

OE

 

[MichaelCG]

If your friends are default blocking traffic from clients, then yes changes will be required to their FW to open up the required sites. But if they are like 99% of most home users with open outbound Internet, no changes will be required.

My use of ATT WiFI is hit or miss. When I first got my iPhone 2+ years ago, it was a horrible experience on WiFi. There was major echo issues and my voice was too quiet on the receiving end. I recently re-enabled WiFi calling while traveling in an area with less than stellar cellular coverage, and have had no complaints even after I got back home.

As for a SIP ALG...I have not done a PCAP on the traffic to confirm if you see the SIP or if it is inside a TLS or IPSEC tunnel. This should be easy enough to validate though.

 

[MichaelCG]

PCAP confirmed, it is not SIP traffic your FW will see. It is an IPSEC tunnel. I am pretty sure this is how TMO operates as well...it has been 6+ years since I was a TMO customer though. We used TMO for 3 years prior to ATT and were very dependent upon WiFi calling and used it with no real complaints.

So in summary:
- no changes to the network/router assuming outbound FW access is allowed
- if Android, it must be an ATT branded device that supports WiFi calling
** my Moto G5+ does NOT support it since it is not an ATT branded phone since it was purchased directly from moto
- if Apple, it can be any device with a somewhat modern version of the OS
** I am using an iPhone6 currently
- WiFi calling must manually be enabled on the device

 

[sfx2000]

I am not sure of the right spot so you can move this if it is wrong.

I installed IOS 11.3 on my iPhone 7+ yesterday. It asked if I want to setup AT&T WiFi calling and I did. This falls right in line with my setup of multiple Cisco WAP371 units in my house. I want to test and see if I can switch APs and not drop calls.

On to my question. I have friends which have late AT&T iPhones and they live in the country without cell coverage. Is there a way to setup WiFi calling for receiving calls through their router. If they setup their iPhones for AT&T WiFi calling what needs to change on their router? Do you have to open ports? Do you need to turn on SIP? I have never made any changes for my wife using FaceTime.

ATT Voice over WiFi calling uses the same architecture as their Voice over LTE (VoLTE) - It leverages into their 3GPP IMS infrastructure, and works fairly well - e.g. it can and should actually handover from WiFi to LTE when you go out of coverage of the WiFi. At least in my experience, it does.

To get the most out of ATT VoWIFI calling - make sure that VoLTE is also enabled - to do this, go to settings -> Cellular -> Cellular Data Options -> Enable LTE, and check that "Voice & Data" is the selection.

As for outside of the home - the VoWIFI client attempts to set up a secure IPSEC tunnel to an ATT edge server - if the connection cannot be made, then calls are done over LTE, with a VCC fallback to 3G voice.

It generally works fairly well on iOS for supported devices - the one caveat I have with VoWIFI - it's nice for home usage - and that includes E911 calls, which might be important. The concern, and this is prompted in the WiFi calling setup, is that one has to register the location - this again is for 911 services in the event that 3G/4G/VoLTE isn't available - in that case, and yes, it might be an edge case, is that the E911 would reflect the last location registered in ATT's platform.

VoLTE calls are zer0-rated, it's not counted against the data allocation in your home network, but VoWIFI minutes are counted for voice calling, so something to consider if overseas, or if one is on a voice minutes oriented rate plan.

Check with ATT's info there with how it works with your plan.

One potential downside - VoWIFI and VoLTE can impact battery life a bit, depends on coverage - so sometimes it's better, and sometimes, there is a cost.

 

[mjc775]

When I tested AT&T WiFi calling after it first launched on the iPhone, it successfully held the call while roaming between my main router and wired extender.


Sent from my iPhone using Tapatalk

 

[avtella]

I am not sure of the right spot so you can move this if it is wrong.

I installed IOS 11.3 on my iPhone 7+ yesterday. It asked if I want to setup AT&T WiFi calling and I did. This falls right in line with my setup of multiple Cisco WAP371 units in my house. I want to test and see if I can switch APs and not drop calls.

On to my question. I have friends which have late AT&T iPhones and they live in the country without cell coverage. Is there a way to setup WiFi calling for receiving calls through their router. If they setup their iPhones for AT&T WiFi calling what needs to change on their router? Do you have to open ports? Do you need to turn on SIP? I have never made any changes for my wife using FaceTime.

As for your rural friends, they should not have to make any changes on the router though on some you may need to disable SIP ALG, as some routers have a terrible implementation that can cause call issues.

 

[sfx2000]

On to my question. I have friends which have late AT&T iPhones and they live in the country without cell coverage. Is there a way to setup WiFi calling for receiving calls through their router. If they setup their iPhones for AT&T WiFi calling what needs to change on their router? Do you have to open ports? Do you need to turn on SIP? I have never made any changes for my wife using FaceTime.

With ATT Wifi Calling - since the device initiates an IPSEC tunnel to their edgeserver, the SIP/ALG issues should not be a problem.

Note that only certain iPhone models support WiFi calling on ATT (iPhone 6s and later, if I recall correctly, check with them).

Outside of WiFi calling - Microcell's are definitely an option - I've used ATT and Sprint, and they work with most handsets, and like WiFi calling, the SIP/ALG thing shouldn't be a problem with them. The main thing with the Microcells - make sure they're near a window, as they need GPS for system timing and to ensure license compliance so they're within the boundaries of the operators license. They're good for voice calls, UMTS-WCDMA for ATT and 2G-CDMA for Sprint, so data is better over the broadband WiFi connection.

On a Microcell - voice and data billing is the same as it would be over the regular wireless network.

 

[CaptainSTX]

Micro Cells IMHO work much better and more reliably than WiFi calling. T-Mobil stopped offering their rebranded ASUS routers which were supposedly optimized for WiFi calling and dumped them on the surplus market because for every problem they solved they created another. For people that complained about weak signals you could get a micro-cell for the same deposit they charged for the T-Mobil router.

I still use WiFi calling but only when I am in a building that totally blocks cell service but does have decent public WiFi.

 

[avtella]

I used to have the Sprint Airave as Sprint had a terrible network in my area before switching to TMO 4 years back, biggest problem was call hand-offs to and from the microcell. Not to mention it uses your internet and if you have low speeds especially on the upload side it won't be that great, Sprint at least allows white lists on their Airave but some companies don't which could be worse for your internet (assuming if speeds are already low which is common in rural settings. If there is some signal a 3G/LTE booster might be better at least the TMO one was decent when I tested it.

 

[sfx2000]

@avtella - understood with your Sprint experience - challenge is that if one needs the Microcell to provide coverage at the house, once one is out of range of the microcell, one is back to the original problem

ATT Microcells - one has to allow handsets to access to the Microcell (e.g. Whitelist) for a handset to use it. ATT WiFi calling, on the other hand, if the client can establish the tunnel, it will use it.

Bandwidth needs on ATT WiFi calling are pretty low - I've had good calls on hotel connections - many of which are very BW limited, e.g. 512Kbps is good enough.