About clients and servers
SCO networking is based on the ``client-server'' model.
In its simplest form, a
``client'' is a program that requests a service and a
``server'' is a program that provides a service. In a
networked environment, client programs frequently issue
RPCs (Remote Procedure Calls) to request that an
operation be performed; a server responds to the RPC
by executing procedures to perform the operation and sending a
response to the client. The terms may also refer to machines;
``server'' may refer to a host whose files or services are made
available through RPCs, and ``client'' to the
requesting host.
The implications of the terms ``client'' and ``server'' may vary in specific networking components. The following table summarizes some of these variations.
Table 1-1 Examples of client-server implementations in SCO networking components
-------------------------------------------------- Component Client Server -------------------------------------------------- DNS any program that any program that (Domain queries for host responds to Name names and queries for host Service) addresses information -------------------------------------------------- NFS any host any host that (Network requesting that ``exports'' file File a remote file systems for System) system be remote mounting mounted locally -------------------------------------------------- NIS any host that any host that (Network requests NIS- fulfills requests Information managed for NIS-managed Service) information information across the network -------------------------------------------------- SNMP also called also called (Simple ``management ``agent''; any Network station''; any program that Management program that responds to Protocol) queries for queries from a system status management information from station a remote systemSCO OpenServer systems provide both client and server administrative functionality; as servers, SCO systems can easily manage other machines using standard technology, while as clients, they can be managed remotely using these technologies.