Wireless Access

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WiFi Calling Fails

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  • 1.  WiFi Calling Fails

    Posted Mar 08, 2021 11:57 PM

    I've got a 7010 controller in standalone mode running 8.7.1.1 at home to learn more about Aruba. Unfortunately it is too expensive to renew the maintenance so I'm hoping for some guidance here. 

    Following the User Guide I have configured it for allowing WiFi Calling. At home we all have AT&T and the Aruba dashboard shows some stats for the UCC but a lot of the connections show multiple hours of activity when the phone is not in use. The most common issue is that our iOS devices show that WiFi calling is connected but if you try to make a call it tries for 30 seconds and then fails to non-WiFi calling. 

    I've tried to troubleshoot what could be causing it but I haven't found anything yet.

    Any ideas/tips on what to check to make it work as expected?



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    Josh Mikow
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  • 2.  RE: WiFi Calling Fails

    Posted Mar 16, 2021 03:57 AM
    "wifi calling" should work without enabling the wifi calling feature. Carriers typically use udp 4500 to make calls over wifi and the controller attempts to detect traffic going to/from specific URLs to see if there is a "call" in place.  This process is not perfect, but just simply not blocking any udp 4500 traffic should allow you to make calls.

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    Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.
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  • 3.  RE: WiFi Calling Fails

    Posted Mar 16, 2021 11:46 PM
    Makes sense if the port is open that it should work. Is there a way to confirm that UDP 4500 is open as a result of the rules? I'm wondering if my Aruba is set fine but maybe my modem/router is causing the problem. If I can at least confirm the Aruba is set correctly I can check other areas.

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    Josh Mikow
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  • 4.  RE: WiFi Calling Fails

    Posted Mar 18, 2021 04:58 AM
    On the commandline of the controller, type "show datapath session table <ip address of client>". Do you should see if there is any port 4500 traffic passing and whether or not there are "D" flags (denies).

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    Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.
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  • 5.  RE: WiFi Calling Fails

    Posted 23 days ago
    Sorry for the slow reply, I finally got a chance to test this out with a couple of our phones. Here's what we see for port 4500:


    Source IP or MAC Destination IP Prot SPort DPort Cntr Prio ToS Age Destination TAge Packets Bytes Flags CPU ID
    ----------------- --------------- ---- ----- ----- -------- ---- --- --- ----------- ---- ---------- ---------- --------------- -------
    192.168.25.253 107.125.50.51 17 4500 4500 0/0 0 0 1 local 37 8 398 FSCA 7
    192.168.25.241 107.125.34.51 17 4500 4500 0/0 0 0 0 local 1c 4 116 FSCA 7​

    Right after each of our phones have a call that fails, it appears it goes from FSCA to FSC on the flags. 

    Typically, the phone will show it's on AT&T Wi-Fi calling, try to make a call, it takes up to 30 seconds to fail, then it goes through successfully but it doesn't seem to be on the WiFi calling. As soon as you hang up it shows that it's back on WiFi Calling.

    Could the S (Source NAT) or A (Application Firewall Inspect) be causing the issue?

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    Josh Mikow
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  • 6.  RE: WiFi Calling Fails

    Posted 21 days ago
    Possibly. How are you source-natting the traffic?

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    Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.
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  • 7.  RE: WiFi Calling Fails

    Posted 20 days ago
    Hi,
    we do use wifi calling with Vodafone. So we had problems with wifi calling too. It was caused by wrong public dns server.
    We finally got a list of supported public dns servers from provider. After changing DNS server for the clients, wifi calling is working.

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    Florian Kueck
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