Is connection to database continues on constant port (port sharing) or redirection (forwarded to oth

Hi,

I have very important questions to Oracle experts. We are implementing Quality of service on our connections.

In QoS we have to declare oracle port on which we can connect to customers databases. If we can do it (for example 1521, 1526) we can use 40% of connection for it, if we can not declare port we will have only 4% of it.

My question is:

What is default kind of listener work: Port sharing or redirection?

Port sharing - constant port for example 1521

Redirection - forworded for oher port.

If it is redirection we will have problem. Maybe some of You has the same problem? Please give me link to some documentation in this subject.