From: Fritz Wuehler Subject: Re: sending a "beep" from computer to mobile phone? MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit References: <2d2485e62cd2c4a3a99075bf3cd127d5@msgid.frell.theremailer.net> Message-ID: Date: Sun, 02 Apr 2023 00:06:13 +0200 Newsgroups: comp.os.linux.misc Path: csiph.com!news.mixmin.net!sewer!news.dizum.net!not-for-mail Organization: dizum.com - The Internet Problem Provider X-Abuse: abuse@dizum.com Injection-Info: sewer.dizum.com - 2001::1/128 Xref: csiph.com comp.os.linux.misc:37707 Pancho [P]: P> The problem with android VoIP softphones is that they tend to P> deregister. So the ring isn't reliable. You just don't get it, do you? Calling a device by its (LAN) IP has no need for registration. Try it some time and see how it goes. I have been using a similar technique (ie. calling a VoIP device by IP, which actually is the remote end of a point-to-point VPN) for ages. This type of communication doesn't need (or leak) anything from (or to) the internet at large. As long as the participating VoIP clients don't crash or otherwise misbehave and the connection channel stays up, whether the registar knows about their current availability status, IPs and audio ports (or is able to talk to them at all) is totally irrelevant. If you need more convincing consider the following scenario: a VoIP device having multiple IPs (physical or virtual). It publishes one of them (via the registrar), but (assuming it has been configured to listen on all of them) it can also be called by anyone on the other (non-published) networks. Do you get it now?