<story><title>VoWiFi</title><url>https://computer.rip/2022-03-24-VoWiFi.html</url></story><parent_chain></parent_chain><comment><author>AshamedCaptain</author><text>You don&amp;#x27;t need eUICC or anything of the sort to do roaming, which is just what he&amp;#x27;s describing. Even the behavior with the international prefix on numbers.&lt;p&gt;Also, the simultaneous data + voice story is kinda more complicated. You couldn&amp;#x27;t do simultaneous voice+data on 2G phones. You could do it on UMTS&amp;#x2F;HSDPA for sure (it was one of the marketing points...). Then when LTE came, for a time phones could not do phone calls over LTE (VoLTE) (something which I was told was just a &amp;quot;missing software thing&amp;quot;) so they had to drop down to some 3G standard during any phone call. If your 3G standard didn&amp;#x27;t have support for simultaneous voice+data, like it used to be on CDMA networks, then you just didn&amp;#x27;t have data (see CDMA iPhone 5). But it was just fine on GSM ones.</text></comment>
<story><title>VoWiFi</title><url>https://computer.rip/2022-03-24-VoWiFi.html</url></story><parent_chain></parent_chain><comment><author>mdb31</author><text>Yes, when roaming, VoWiFi or VoLTE can have quite unexpected results due to your &amp;#x27;data&amp;#x27; being backhauled to your &amp;#x27;home&amp;#x27; provider, for both billing and dialing. Former you can&amp;#x27;t do much about, except complain when things go wrong, but as for numbers: always store (and dial) these in +countrycode-subscribernumber (minus the leading 0, &lt;i&gt;unless&lt;/i&gt; it&amp;#x27;s an Italian number, +39) format, and you&amp;#x27;ll be mostly* fine.&lt;p&gt;*Unless visiting countries that have providers with woefully misconfigured dial plans, say, Nigeria...</text></comment>