LDAP lookup doesn't work, though directory is basically searchable (T56A / T58)

[Mr_Christian]

Hi,

we have several T56A and T58V which work in conjunction with a 3CX telephone system. The phones are configured to resolve the incoming / outgoing number. But though we can search the directory through the LDAP telephone book, we neither see the name of who is calling nor the name of who we are calling. Instead we see the plain telephone number.

Here is our configuration (see attached screenshot):

ldap.base = dc=3cx
ldap.call_in_lookup = 1
ldap.customize_label = Telefonbuch
ldap.dial_lookup = 1
ldap.display_name = %displayName
ldap.enable = 1
ldap.host = 192.168.182.7
ldap.name_attr = displayName cn sn
ldap.name_filter = (|(searchContact=%)(searchNumber=%))
ldap.numb_attr = telephoneNumber
ldap.number_filter = (searchNumber=%)
ldap.port = 712
ldap.user = 3cx

The LDAP directory is an Estos Metadirectory in version 4.0.3.5828. This directory supports special queries using searchContact and searchNumber which internally searches several fields and also takes care of formatting issues (like with or without country prefix, +49... or 0049..., and so on).

Using wireshark (see other screenshot), I could see that the LDAP server has been queried by the phone but - if I interpret it correctly - without any number within the LDAP-filter. Thus the result is not a single fitting contact but rather a list of non-fitting contacts (being the first entries of the whole directory). The phone presumably double-checks the number or can't handle the result having so many entries and thus shows nothing but the plain number.

I guess that the number which is sent to the LDAP server is not determined correctly. But why? How does the phone decide which number it sends to the LDAP server? And can I somehow configure this?

Thank you very much for your help!

Best regards
Chris

PS: Tested firmwares are 58.80.0.40 (newest) and 58.80.0.25.