<div dir="ltr">Hi James,<div><br></div><div>WiFi Calling uses the same backend as VoLTE.</div><div><br></div><div>With the 3G network switch off, VoLTE has required some tweaks recently to ensure that 000 emergency calls still work as expected when a device is out of coverage with its Mobile provider, but within the coverage of another.</div><div><br></div><div>This is because 3G gives a circuit out of the box, but Voice on an LTE network requires establishing a data connection with an unknown party first before a Voice call can be overlaid on it. Normally telcos don't just allow data sessions to subscribers they don't know, and at the time the session is established the intent for it to be an emergency call isn't known.</div><div><br></div><div>If the problems started occurring around the same time 3G switched off then you may have found a place to start looking for a fault - there was almost certainly a software or config upgrade to voice systems.</div><div><br></div><div>Trivia: The standard for LTE emergency call functionality was developed by Huawei for Australia's TPG Telecom in their Singapore rollout, the 2nd LTE-only mobile network globally, after Reliance Jio in India (I may have heard they used an app-based approach to solve emergency calling)</div><div><br></div><div>John</div><div> </div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, 28 Nov 2024 at 18:37, James Andrewartha <<a href="mailto:trs80@ucc.gu.uwa.edu.au">trs80@ucc.gu.uwa.edu.au</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex">Hi,<br>
<br>
The past month or so some of our staff (whose desks don't get good Telstra <br>
coverage) have been complaining about calls going straight to voicemail <br>
when wifi calling is enabled (which we suggested due to the coverage <br>
issues).<br>
<br>
Doing a packet capture, I can see the IPsec tunnel being established to <br>
<a href="http://epdg.epc.mnc001.mcc505.pub.3gppnetwork.org" rel="noreferrer" target="_blank">epdg.epc.mnc001.mcc505.pub.3gppnetwork.org</a>. Some of the users have public <br>
IPs, others are behind NAT.<br>
<br>
Does anyone have any tips on working out why they'd be having issues all <br>
of a sudden?<br>
<br>
Thanks,<br>
<br>
-- <br>
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# UCC Wheel Member <a href="http://trs80.ucc.asn.au/" rel="noreferrer" target="_blank">http://trs80.ucc.asn.au/</a> #| what squirrels do best |<br>
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