Hi Joel, Actually, I have a strange issue. If I have a single UDP IP:Port listening, most Providers/Phones have two-way Audio/Video, however, with some Providers/Phones, I need to have two UDP IP:Port listners in order to get two-way Audio/Video. Here is the strange thing. If I enable two, the Providers/Phones that worked when I had a single listener only have one-way Audi/Video. I use Kamailio 5.1 and Asterisk 15.3 (pjsip). This behavior is so strange, Thank you, -Steve From: sr-users &lt;sr-users-bounces(a)lists.kamailio.org&gt; On Behalf Of Joel Serrano Sent: Friday, August 24, 2018 2:17 PM To: Kamailio (SER) - Users Mailing List &lt;sr-users(a)lists.kamailio.org&gt; Subject: Re: [SR-Users] add listen dynamically If you know the ips in advance you can specify all listen= params and enable the kernel ipv4_nonlocal_bind Another option would be to add listen=* and have kamailio listen on anything the OS has enabled..? Have you tried these couple options? Not sure if they would work without more details of what you are trying to achieve. On Fri, Aug 24, 2018 at 10:35 Wilkins, Steve <swwilkins@mitre.org<mailto:swwilkins@mitre.org>> wrote: Hi All, Is it possible to add or remove “listen” dynamically? Thank you, -Steve _______________________________________________ Kamailio (SER) - Users Mailing List sr-users@lists.kamailio.org<mailto:sr-users@lists.kamailio.org> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users