how WSDL tells if WebService is one way or two way.

The port type  should have input and output. input before ouptput indicates that in coming msg shud come before outgoing.

<portType name="BookQuote">

  <operation name="getBookPrice">

     <input name="isbn" message="mh:GetBookPriceRequest"/>

     <output name="price" message="mh:GetBookPriceResponse"/>

     <fault name="InvalidArgumentFault" message="mh:InvalidArgumentFault"/>

     <fault name="SecurityFault" message="mh:SecurityFault"/>

  </operation>

</portType>

and one way messaging is like

<portType name="SubmitPurchaseOrder_PortType">

  <operation name="SubmitPurchaseOrder">

     <input name="order" message="mh:SubmitPurchaseOrderMessage"/>

  </operation>

</portType>