These settings enable listing address book entries:
Common username: <domain>\<extension> e.g. pbx.xyz.net\1234
Common password: web password of the extension (not PIN or SIP password)
(^- mobile device specific authentication should work the same way)
LDAP search base: ou=people
Name filter: (|(sn=%)(gn=%))
Number filter: (|(telephoneNumber=%)(mobile=%))
While this allows listing entries, it doesn't allow to view details or call them. Looking at the LDAP requests/responses, the conversation looks like this:
Initial listing of address book:
searchRequest "ou=people" wholeSubtree
searchResDone success [x results]
Trying to call entry:
searchRequest "Some Name" baseObject
It's asking for these attributes: sn, givenName, telephoneNumber, all of which exist and work in the initial listing.
Also, Filter is (objectClass=*). This is the only difference I see from the request sent in the initial listing.
searchResDone success [0 results]
This does look a bit like a minor bug in the LDAP implementation of the server, since the searchRequest looks correct to retrieve the single object in question. It's the correct objectName specified in the baseObject field, as it received in the earlier searchResEntry response.