--- channels/chan_sip.c (Asterisk 13.11.2) +++ channels/chan_sip.c (working copy) @@ -16739,6 +16739,7 @@ static enum parse_register_result parse_ } if ((transport_type != AST_TRANSPORT_WS) && (transport_type != AST_TRANSPORT_WSS) && + (transport_type != AST_TRANSPORT_TCP) && (transport_type != AST_TRANSPORT_TLS) && (!ast_test_flag(&peer->flags[0], SIP_NAT_FORCE_RPORT) && !ast_test_flag(&peer->flags[0], SIP_NAT_RPORT_PRESENT))) { /* use the data provided in the Contact header for call routing */ ast_debug(1, "Store REGISTER's Contact header for call routing.\n");