title: No application 'Dial' for extension error in Asterisk
body: <p>I have three extensions with extension no. <code>2000</code>,<code>2001</code>,<code>2002</code>.Separately i am able to call from one extension to another. While calling the any extension it getting error like this <strong>No application 'Dial' for extension error in Asterisk</strong></p>
  
  <p>My <code>sip.conf</code> like this</p>
  
  <pre><code>[general]
  port = 5060
  bindaddr = 0.0.0.0
  context = others
  
  [2000]
  type=friend
  context=demo
  secret=1234
  host=dynamic
  
  [2001]
  type=friend
  context=demo
  secret=1234
  host=dynamic
  
  [2002]
  type=friend
  context=demo
  secret=1234
  host=dynamic
  </code></pre>
  
  <p>and <code>extensions.conf</code></p>
  
  <pre><code>[demo]
  exten =&gt; 2000, 1, Dial (SIP/2000)
  exten =&gt; 2000, 2, Voicemail (u2000)
  exten =&gt; 500, 1,Answer()
  exten =&gt; 500, 2, playback(demo-echo)
  exten =&gt; 500, 3, Echo
  exten =&gt; 500,5,Hangup
  
  exten =&gt; 2001, 1, Dial (SIP/2001)
  exten =&gt; 2001, 2, Voicemail (u2001)
  
  exten =&gt; 2002, 1, Dial (SIP/2002)
  exten =&gt; 2002, 2, Voicemail (u2002)
  </code></pre>
  
  <p>please help me how to resolve this issue.Thanks in advance</p>