title: 481 Call Leg/Transaction Does Not Exist using SipUnit
body: <p>I've changed from SIPr to SipUnit, and I'm trying to make a basic call. The server has digest authentication. Unfurnately, I keep getting a "481 Call Leg/Transaction Does Not Exist" and I'm sure it is because of a pretty obvious reason, but I can't seem to solve it... I've tried everything. Here is the critical piece from the PBX's logs. Thanks in advance, if someone can explain to me why this is happening!</p>
  
  <pre><code>- --&gt; SIP/2.0 407 Proxy Authentication Required
  -     From: &lt;sip:6000@auto&gt;;tag=126319630
  -     To: &lt;sip:6001@auto&gt;;tag=2ff812a8-da5512ac-1b94-6006-5a9c94-45273d5a-5a9c94
  -     Call-ID: e0114805d5e2e318089ce3ef710aad63@10.200.10.59
  -     CSeq: 1 INVITE
  -     Contact: &lt;sip:6001@172.18.85.218:1060&gt;
  -     Proxy-Authenticate: Digest realm="radvision.com",nonce="c0cf196770955ca0fc6e3e65dc0cdb410000000055c1cef4",algorithm=MD5
  -     Via: SIP/2.0/UDP 10.200.10.59:9001;received=172.18.85.218;rport=1060;branch=z9hG4bK-373136-f42a6651eba8e1583353591126fdf561
  -     Content-Length: 0
  
  
  
  - &lt;-- ACK sip:6001@auto SIP/2.0
  -     Call-ID: e0114805d5e2e318089ce3ef710aad63@10.200.10.59
  -     Max-Forwards: 70
  -     From: &lt;sip:6000@auto&gt;;tag=126319630
  -     To: &lt;sip:6001@auto&gt;;tag=2ff812a8-da5512ac-1b94-6006-5a9c94-45273d5a-5a9c94
      -     Via: SIP/2.0/UDP 10.200.10.59:9001;branch=z9hG4bK-373136-f42a6651eba8e1583353591126fdf561
  -     CSeq: 1 ACK
  -     Route: &lt;sip:172.18.85.218:1060;lr;transport=udp&gt;
  -     Content-Length: 0
  
  
  
  - &lt;-- INVITE sip:6001@auto SIP/2.0
  -     Call-ID: e0114805d5e2e318089ce3ef710aad63@10.200.10.59
  -     CSeq: 2 INVITE
  -     From: &lt;sip:6000@auto&gt;;tag=126319630
  -     To: &lt;sip:6001@auto&gt;;tag=2ff812a8-da5512ac-1b94-6006-5a9c94-45273d5a-5a9c94
  -     Via: SIP/2.0/UDP 10.200.10.59:9001;branch=z9hG4bK-373136-a29ab2f2fc28a3f00e2cd290bac58473
  -     Max-Forwards: 70
  -     Contact: &lt;sip:6000@10.200.10.59:9001;transport=udp;lr&gt;
  -     Route: &lt;sip:172.18.85.218:1060;lr;transport=udp&gt;,&lt;sip:172.18.85.218:1060;lr;transport=udp&gt;
  -     Proxy-Authorization: Digest username="6000",realm="radvision.com",nonce="c0cf196770955ca0fc6e3e65dc0cdb410000000055c1cef4",uri="sip:6001@auto",response="79af22055592634e57d5c17e59da166e",algorithm=MD5
  -     Content-Length: 0
  
  
  
  - --&gt; SIP/2.0 481 Call Leg/Transaction Does Not Exist
  -     From: &lt;sip:6000@auto&gt;;tag=126319630
  -     To: &lt;sip:6001@auto&gt;;tag=2ff812a8-da5512ac-1b94-6006-5a9c94-45273d5a-5a9c94
  -     Call-ID: e0114805d5e2e318089ce3ef710aad63@10.200.10.59
  -     CSeq: 2 INVITE
  -     Via: SIP/2.0/UDP 10.200.10.59:9001;branch=z9hG4bK-373136-a29ab2f2fc28a3f00e2cd290bac58473
  -     Content-Length: 0
  </code></pre>
  
  <p>I'm using code similar to the example TestWithProxyAuthentication.java.</p>