3.1.4.1.31.6 Remote Shell Compression
To optimize network bandwidth, the Web Services Management Protocol Extensions for Windows Vista clients MAY send the optional SOAP header CompressionType as part of a wst:Create request for a remote shell to indicate that the data sent as part of the ensuing Send and ReceiveResponse messages will be compressed as specified in section 3.2.4.1.19.
On receipt of the CompressionType SOAP header, the Web Services Management Protocol Extensions for Windows Vista Service MUST compress any data sent in a ReceiveResponse message by using the specified compression algorithm.