title: What is H.450.2? What happens when it doesn't exist?
body: <p>What is <a href="http://www.protocols.com/pbook/h323.htm#H4502" rel="nofollow">H.450.2</a>? </p>
  
  <p>I noticed that many applications such as Ekiga for linux/windows allowes this. But many others does not, as a result i see some problems which confusing me and having no answer to move forward. But i am not sure what it has to do for call scenarios as following:</p>
  
  <pre><code>Endpoint 1 &lt;-------&gt; (H.323 gatekeeper) &lt;------&gt; Endpoint 2
                             |
                  Administrator remotely place an call 
                (root@gw~$ makecall endpoint1 endpoint2)
  </code></pre>
  
  <p>Gatekeeper have registered users 1 and 2. From the gatekeeper action is triggered to connect user 1/2. If user 1 and user 2 has no H.450.2 protocol support or built in, can gatekeeper send call signal to them?  However User1 can dial to User2, and gatekeeper gets call signal.</p>
  
  <p>Thanks for your advise</p>