7.1 Actors

DHCP Server

The DHCP Server is a computer/software feature that is provided with a network configuration description, and that provides startup configuration services in accordance with the DHCP protocol.

DHCP Client

The DHCP Client is a software feature that is used to obtain TCP/IP parameters during the startup of a computer. It continues operation to maintain validity of these parameters.

DNS Server

The DNS server is a computer/software feature that provides IP related information in response to queries from clients utilizing the DNS protocol. It is a part of a federated database facility that maintains the current database relating machine names to IP address information. The DNS server may also be isolated from the worldwide federated database and provide only local DNS services.

DNS Client

The DNS client as a computer/software feature that utilizes the DNS protocols to obtain IP information when given hostnames. The hostnames may be in configuration files or other files instead of explicit IP addresses. The hostnames are converted into IP addresses dynamically when necessary. The DNS client uses a DNS server to provide the necessary information.

NTP Server

The NTP server is a computer/software feature that provides time services in accordance with the NTP or SNTP protocol.

NTP Client

The NTP client is software that obtains time information from an NTP server and maintains the client time in synchronization with the time signals from the NTP server.

SNTP Client

The SNTP client is software that obtains time information from an NTP server and maintains the client time in approximate synchronization with time signals from the NTP server. The SNTP client synchronization is not maintained with the accuracy or precision that NTP provides.

LDAP Server

The LDAP server is a computer/ software feature that maintains an internal database of various directory information. Some of this directory information corresponds to DICOM Configuration schema. The LDAP server provides network access to read and update the directory information. The LDAP server provides a mechanism for external loading, unloading, and backup of directory information. The LDAP server may be part of a federated network of servers that provides a coordinated view of a federated directory database in accordance with the rules of the LDAP protocols.

LDAP Client

The LDAP client utilizes the LDAP protocol to make queries to an LDAP server. The LDAP server maintains a database and responds to these queries based on the contents of this database.