   <?xml version="1.0" encoding="UTF-8"?>
     <xs:schema
       targetNamespace="urn:ietf:params:xml:ns:sa-dialog-info"
       xmlns="urn:ietf:params:xml:ns:sa-dialog-info"
       xmlns:xs="http://www.w3.org/2001/XMLSchema"
       elementFormDefault="qualified">


      <xs:element name="joined-dialog" minOccurs="0"
                                            maxOccurs="unbounded">
           <xs:complexType>
               <xs:attribute name="call-id" type="xs:string"
                 use="mandatory"/>
               <xs:attribute name="local-tag" type="xs:string"
                 use="mandatory"/>
               <xs:attribute name="remote-tag" type="xs:string"
                 use="mandatory"/>
           </xs:complexType>
      </xs:element>

      <xs:element name="replaced-dialog" minOccurs="0"
                                             maxOccurs="unbounded">
           <xs:complexType>
               <xs:attribute name="call-id" type="xs:string"
                 use="mandatory"/>
               <xs:attribute name="local-tag" type="xs:string"
                 use="mandatory"/>
               <xs:attribute name="remote-tag" type="xs:string"
                 use="mandatory"/>
           </xs:complexType>
       </xs:element>

       <xs:element name="appearance" minOccurs="0" maxOccurs="1">
           <xs:simpleType type="xs:integer">
           </xs:simpleType>
       </xs:element>

       <xs:element name="exclusive" minOccurs="0" maxOccurs="1">
           <xs:simpleType type="xs:boolean">
           </xs:simpleType>
       </xs:element>
</xs:schema>