Local (DCOM) connections are only supported for ArcGIS Server versions prior to 10.1.
About working with SOAP
This section in the software development kit (SDK) includes topics to assist you in developing with the ArcGIS Server Simple Object Access Protocol (SOAP) application programming interface (API).
See Also:
Implementing the ArcGIS Server SOAP APIConsuming SOAP services
Serialization in the SOAP API