3.23 Find Personnel White Pages [ITI-23]

This section corresponds to transaction [ITI-23] of the IHE IT Infrastructure Technical Framework. Transaction [ITI-23] is used by the Personnel White Pages Consumer and the DNS Server Actors.

3.23.1 Scope

This transaction is used to locate the Personnel White Pages directory.

3.23.2 Use Case Roles

Actor: Personnel White Pages Consumer

Role: Requests Locating information for the Personnel White Pages Directory

Actor: DNS Server

Role: Provides locating information about the Personnel White Pages Directory

3.23.3 Referenced Standard

IETF:

• RFC2181 Clarifications to the DNS Specification
• RFC2219 Use of DNS Aliases for Network Services
• RFC2782 A DNS RR for specifying the location of services (DNS SRV)

DICOM: 

• DICOM Supplement 67 – Configuration Management

Note: Normative RFC’s are frequently updated by issuance of subsequent RFC’s. The original older RFC is not modified to include references to the newer RFC. This transaction lists the applicable RFC’s in effect at the time of publication. Subsequent updates and clarifications to these RFC’s should also be applied.

3.23.4 Messages

3.23.4.1 Request all LDAP servers

The RFC2782 DNS RR is used for specifying the location of services (DNS SRV). It specifies a mechanism for requesting the names and rudimentary descriptions for machines that provide network services. The DNS client requests the descriptions for all machines that are registered as offering a particular service name. In this case the service name requested will be “_ldap._tcp”. The DNS server may respond with multiple names for a single request.

3.23.4.1.1 Trigger Events

This transaction is used by the Personnel White Pages Consumer prior to any access to the Personnel White Pages Directory.

3.23.4.1.2 Message Semantics

The Personnel White Pages Consumer shall request a list of all the LDAP servers available. The Personnel White Pages Consumer shall use the priority, capacity, and location information provided by DNS as part of the server selection process. (RFC2782 recommends the proper use of these parameters).

Notes:

-- Multiple LDAP servers providing access to a common replicated LDAP database is a commonly supported configuration. This permits LDAP servers to be located where appropriate for best performance and fault tolerance. The DNS server response information provides guidance for selecting the most appropriate server.

-- There may also be multiple LDAP servers providing different databases. In this situation the client may have to examine several servers to find the one that supports the Personnel White Pages Directory (see Section 3.24.4.1.2.2).

-- The client may have a mechanism for manual default selection of the LDAP server to be used if the DNS server does not provide an LDAP server location.

3.23.4.1.3 Expected Actions

The DNS Server shall return all known LDAP servers in accordance with RFC2782.