Advanced Customization > Info*Engine User’s Guide > SOAP Services > Legacy Services
  
Legacy Services
When running Windchill, it is recommended that you use the SimpleTaskDispatcher servlet rather than the RPC servlet. The two servlets behave identically externally, but in the case of a Windchill installation, the SimpleTaskDispatcher delegates directly to the SimpleTaskDispatcher service running in your MethodServer. As a result, this servlet performs better than the standalone Info*Engine RPC servlet.
In the following topics, wherever there is a reference to the RPC servlet address, you can simply replace “RPC” with “SimpleTaskDispatcher” in that URL.
For example:
http://<host>/Windchill/servlet/RPC
can be replaced with
http://<host>/Windchill/servlet/SimpleTaskDispatcher
* 
If your site is using form-based authentication, programmatic clients attempting to access the RPC or SimpleTaskDispatcher servlet must use the /protocolAuth URL prefix. For example:
http://<host>/Windchill/protocolAuth/servlet/SimpleTaskDispatcher
or
http://<host>/Windchill/protocolAuth/servlet/RPC
For more information about form-based authentication, see Form-based Authentication.