connecting to Oracle without using the tnsnames or host method

new to te Oracle 10G SQLNet network is the possibility to connect directly to a database. An Entry in tnsnames.ora or sqlnet.ora is not needed. Syntax for this connect string is:

user/password@//host/servicename

You can use this with sqlplus or even when creating a database link within a database:

create ... database link .... using 'user/password@//host/servicename'

it works only for sqlnet over tcp/ip and with a listener on the default port. when using nondefault ports use ....@//host:port/servicename