The destination file name used to store the captured frames.
Value of this object must be specified in the format
of <device>:<filename> for local location, or
<protocol>://<server>/<filename> for network location.
This object may not be modified if value of the corresponding
instance of cpcSessionOperStatus is 'inProgress' or the value
of cpcBufferOperStatus of an instance entry with same
cpcSessionId in cpcBufferConfigEntry is 'exporting'.