AudioCodes Mediant 4000 SBC User Manual page 250

The handling of LDAP queries using the device's LDAP cache is shown in the flowchart
below:
Figure 15-28: LDAP Query Process with Local LDAP Cache
If an LDAP query is required for an Attribute of a key that is already cached with that same
Attribute, instead of sending a query to the LDAP server, the device uses the cache.
However, if an LDAP query is required for an Attribute that does not appear for the cached
key, the device queries the LDAP server and then saves the new Attribute (and response)
in the cache for that key. When the device queries new Attributes for a cached key, the
device also includes already cached Attributes of the key, while adhering to the maximum
number of allowed saved Attributes (see note below), with preference to the new Attributes.
In other words, if the cached key already contains the maximum Attributes and an LDAP
query is required for a new Attribute, the device sends an LDAP query to the server for the
new Attribute and for the five most recent Attributes already cached with the key. Upon the
LDAP response, the new Attribute replaces the oldest cached Attribute while the values of
the other Attributes are refreshed with the new response. The following table shows an
example of different scenarios of LDAP queries of a cached key whose cached Attributes
include a, b , c, and d, where a is the oldest and d the most recent Attribute:
Table 15-12: Example of LDAP Query for Cached Attributes
Attributes Requested in New
LDAP Query for Cached Key
e
e, f
e, f, g, h, i
e, f, g, h, i, j
User's Manual
Attributes Sent in LDAP Query
to LDAP Server
e, a, b, c, d
e, f, a, b, c, d
e, f, g, h,i, a
e, f, g, h, i, j
250
Mediant 4000 SBC
Attributes Saved in Cache after
LDAP Response
e, a, b, c, d
e, f, a, b, c, d
e, f, g, h,i, a
e, f, g, h, i, j
Document #: LTRT-40203