I am having the same problem! Asterisk 13.4 and iaxmodem 1.3.0. I traced it to a test in chan_iax2.c. It was complaining that the "peer was not dynamic". I commented out that test, and now it registers successfully. / if (!ast_test_flag64(p, IAX_DYNAMIC)) { if (authdebug) ast_log(LOG_NOTICE, "Peer '%s' is not dynamic (from %s)\ goto return_unref; }/ My understanding is that "dynamic" means that a peer does not have a configured IP address - so it is wherever it is. Iaxmodem is of course not "dynamic"...