Failed Session:
 
 <iq type='set' to='2125551212@voice.google.com/srvres' from='user@gmail.com/gtalkXXXXXXXX' id='XXXXX'>
   <session xmlns='http://www.google.com/session' type='initiate' initiator='user@gmail.com/gtalkXXXXXXXX' id='XXXXXXXXXXXXXXXX'>
     <description xmlns='http://www.google.com/session/phone' xml:lang='en'>
	   <payload-type id='0' name='PCMU' clockrate='8000' bitrate='64000'/>
       <payload-type id='100' name='EG711U' clockrate='8000' bitrate='64000'/>
	   <payload-type id='101' name='telephone-event' clockrate='8000'/>
     </description>
   </session>
 </iq>
 
<iq type="error" to="user@gmail.com/gtalkXXXXXXXX" from="2125551212@voice.google.com/srvres" id="XXXXX">
  <session type="initiate" initiator="user@gmail.com/gtalkXXXXXXXX" id="XXXXXXXXXXXXXXXX" xmlns="http://www.google.com/session">
    <description xml:lang="en" xmlns="http://www.google.com/session/phone">
	  <payload-type id="0" name="PCMU" clockrate="8000" bitrate="64000"/>
	  <payload-type id="100" name="EG711U" clockrate="8000" bitrate="64000"/>
	  <payload-type id="101" name="telephone-event" clockrate="8000"/>
	</description>
  </session>
  <error code="400" type="modify"><bad-request xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"/>
  </error>
</iq>




Successful Session:

<iq xmlns="jabber:client" from="user@gmail.com/gtalkXXXXXXXX" to="+12125551212@voice.google.com" type="set" id="XXX">
  <ses:session xmlns:ses="http://www.google.com/session" type="initiate" id="XXXXXXXXX" initiator="user@gmail.com/gtalkXXXXXXXX">
    <pho:description xmlns:pho="http://www.google.com/session/phone" xml:lang="en">
      <pho:payload-type xmlns:pho="http://www.google.com/session/phone" id="0" name="PCMU" clockrate="8000" bitrate="64000"></pho:payload-type>
    </pho:description>
    <transport xmlns="http://www.google.com/transport/p2p"></transport>
  </ses:session>
</iq>

<iq from="+12125551212@voice.google.com" to="user@gmail.com/gtalkXXXXXXXX" type="error" id="XXX">
  <ses:session type="initiate" id="XXXXXXXXX" initiator="user@gmail.com/gtalkXXXXXXXX" xmlns:ses="http://www.google.com/session">
    <pho:description xml:lang="en" xmlns:pho="http://www.google.com/session/phone">
      <pho:payload-type id="0" name="PCMU" clockrate="8000" bitrate="64000"></pho:payload-type>
    </pho:description>
    <transport xmlns="http://www.google.com/transport/p2p"></transport>
  </ses:session>
  <error code="302" type="modify">
    <redirect xmlns="urn:ietf:params:xml:ns:xmpp-stanzas">xmpp:+12125551212@voice.google.com/srvres-XXXXXXXXXXXXXXXXXXXXXXXX</redirect>
    <ses:redirect xmlns:ses="http://www.google.com/session">xmpp:+12125551212@voice.google.com/srvres-XXXXXXXXXXXXXXXXXXXXXXXX</ses:redirect>
  </error>
</iq>

Session continues @ redirect:

<iq xmlns="jabber:client" from="useser@gmail.com/gtalkXXXXXXXX" to="+12125551212@voice.google.com/srvres-XXXXXXXXXXXXXXXXXXXXXXXX" type="set" id="XXY">
  <ses:session xmlns:ses="http://www.google.com/session" type="initiate" id="XXXXXXXXXX" initiator="user@gmail.com/gtalkXXXXXXXX">
    <pho:description xmlns:pho="http://www.google.com/session/phone" xml:lang="en">
      <pho:payload-type xmlns:pho="http://www.google.com/session/phone" id="0" name="PCMU" clockrate="8000" bitrate="64000"></pho:payload-type>
    </pho:description>
    <transport xmlns="http://www.google.com/transport/p2p"></transport>
  </ses:session>
</iq>