apply patch from Jan Willamowius:

make sure dtmfinband gets initialized.
make gk-identifier and gk-interface settings optional (documentation sayed that about gk-identifier already)

src/mod/endpoints/mod_h323/changes.txt

+make sure dtmfinband gets initialized
+make gk-identifier and gk-interface settings optional (documentation sayed that about gk-identifier already)
 fix race condition on destroying signaling thread in h323 library
 Adds an extra switch_rtp_destroy or switch_rtp_release_port when a session ends 
     - to make sure the port is returned to FS. thx to Peter Olsson.

src/mod/endpoints/mod_h323/h323.conf.xml

@@ -9,7 +9,7 @@
     <!-- <param name="ptime-override-value" value="20"/> --> <!-- Override negotiated ptime value with this value -->
     <param name="gk-address" value=""/>    <!-- empty to disable, "*" to search LAN -->
     <param name="gk-identifer" value=""/>  <!-- optional name of gk -->
-    <param name="gk-interface" value=""/>  <!-- mandatory listener interface name -->
+    <param name="gk-interface" value=""/>  <!-- optional UDP listener interface (IP:port) -->
     <param name="gk-retry" value="30"/>  <!-- optional GK register retry timer -->
     <param name="faststart" value="true"/>  <!-- optional -->
     <param name="h245tunneling" value="true"/>  <!-- optional -->

src/mod/endpoints/mod_h323/mod_h323.cpp

@@ -18,6 +18,7 @@
  * License.
  *
  * Contributor(s):
+ * Jan Willamowius.
  * 
  * 
  * 
@@ -223,6 +224,7 @@ class FSTrace : public ostream {
     public:
         Buffer()
             {
+				// leave 2 chars room at end: 1 for overflow char and1 for \0
                 setg(buffer, buffer, &buffer[sizeof(buffer)-2]);
                 setp(buffer, &buffer[sizeof(buffer)-2]);
             }
@@ -440,8 +442,8 @@ bool FSH323EndPoint::Initialise(switch_loadable_module_interface_t *iface)
 		}
 	}
 
-	if (!m_gkAddress.IsEmpty() && !m_gkIdentifer.IsEmpty() && !m_gkInterface.IsEmpty()) {
-		m_thread = new FSGkRegThread(this,&m_gkAddress,&m_gkIdentifer,&m_gkInterface,m_gkretry);
+	if (!m_gkAddress.IsEmpty()) {
+		m_thread = new FSGkRegThread(this, &m_gkAddress, &m_gkIdentifer, &m_gkInterface, m_gkretry);
 		m_thread->SetAutoDelete();
 		m_thread->Resume();
 	}
@@ -592,6 +594,7 @@ FSH323EndPoint::FSH323EndPoint()
 	:m_faststart(true)
 	,m_h245tunneling(true)
 	,m_h245insetup(true)
+	,m_dtmfinband(false)
 	,m_thread(NULL)
 	,m_stop_gk(false)
 	,m_fax_old_asn(false)