TANDBERG 3.0 - Manual (Page 65)

Copyright © TANDBERG 2008 Reference Guide Version 3.0 rev 1.0 61
There are two solutions to this problem; the first is the listAll parameter and the second is described in the
next section. A client may periodically include the listAll Boolean parameter set to true to indicate that the
MCU should return every record available, (enumeration limits still apply so multiple calls using the standard
enumeration protocol may be required). This allows a client to resynchronize to the MCU, because it can
safely assume that any record not returned by this request (or series of requests, in the case of enumerations) is
no longer a record on the MCU.
For example, any participants not returned by participant.enumerate when listAll is set to true can be assumed
to have been removed from the MCU.
The listAll parameter can still be used in conjunction with the lastRevision parameter: doing so means that
every record will be returned, but records that have not changed since the specified revision may have many
members removed from their substructures. Substructures that have had members removed in this way will
contain a field named “changed” instead, which will be set to false indicating that there are no changes to the
data in this substructure since the specified revision number.
C.2 Dead records
The second approach to the record removal problem is the dead parameter. The MCU will maintain a cache of
records that have been removed and are in no sense considered active; a “dead” record will never be returned if
revision numbers are not being used or if the listAll parameter is set to true (e.g. a previous participant record
is still not considered a dead record because it would be returned by a normal participant.enumerate request).
A dead record will be returned by a method supporting revision numbers if the lastRevision parameter
designates a revision at which the record was not yet dead. The returned record will contain only the fields
necessary for its identification and an extra field “dead”, which will be set to true to indicate that this record
should no longer considered to be present on the MCU.
These dead records are only cached on the MCU for a few minutes; therefore a client should not rely on them
unless it is doing very regular polling. When using less frequent polling using the listAll parameter described
above is more appropriate.