In the field of database computing, Oracle Net Services consists of sets of software which enable client applications to establish and maintain network sessions with Oracle Database servers.
Since Oracle databases operate in and across a variety of software and hardware environments, Oracle Corporation supplies high-level transparent networking facilities with the intention of providing networking functionality regardless of differences in nodes and protocols.
Oracle Net (formerly called "SQL*Net" or "Net8"[4]) comprises two software components: The listener process(es) on a server detect incoming requests from clients for connection - by default on port 1521[5] - and manage network-traffic once clients have connected to an Oracle database.
The listener uses a configuration-file - listener.ora - to help keep track of names, protocols, services and hosts.
The listener.ora file can include three sorts of parameters:[6] Apart from pre-defined and known statically-registered databases, a listener can also accept dynamic service registration from a database.