Hotspot for wifi calling

RouterOS General
1

I am trying to set up a hotspot for wifi calling only, with http[s] disabled. It functions as a normal hotspot and I can make calls in and out. However, as soon as I block ports 443 and 80 outgoing, the phone complains there is no internet and when I try to make a call out, it tells me to turn aeroplane mode off.

Now, I think there are 2 things happening here:

  1. In blocking ports 443 and 80, I think that the phone can no longer see a connectivity test address
  2. There is material out there which suggests wifi calling might have a dependency on tcp port 443 to set up an encrypted link

On point 1, when I specifically unblock http[s] from hotspot addresses to the hotspot server, I can sign in to the hotspot, which then relays a complaint that the connectivity check page is unreachable.
So my questions are:

  1. Are the any workarounds for the connectivity check?
  2. Does anyone know either way whether wifi calling depends on https to port 443?
2

Not enough information.
What do you mean wifi calling.
I use my iphone all the time for WIFI calling with no special settings???

I'm assuming the phone attempts to connect to my providers cellular network over VOIP and then routes the call into the regular telephone network..........

It would make sense if the call is protected in some way.

3

It is a thing, I mean this https://en.wikipedia.org/wiki/Wi-Fi_calling So it is using a regular mobile [cell] phone over wireless to make and receive calls on the phone’s normal SIM assigned number, using the wifi as a fairly transparent extension of the mobile network, useful if your mobile phone service does not have connectivity in a location.

4

Yes, its funny, I always assumed it just worked without thinking of the actual traffic flow, how it actually reaches the cellular provider as its going out your house ISP..................

5

@DuctView see here https://community.cisco.com/t5/ip-telephony-and-phones/wifi-calling-port-requirements/td-p/4644034

It seems outgoing tcp 443 is mandatory by most providers for authentication.

You can try to find out which host(s) is using and filter out by destination ip or address list.

1 Like
6

Thanks for this. Not really viable as it will change by operator and I want something suitable for all comers.
Same too for my first point of contention, the connectivity test address, although I think this might be common across all Android phones for example.

But I would like to overcome the first hurdle to see if tcp 443 is really an essential protocol to wifi calling