Listen on specific port/ip for incoming connections?

Hi all,

Can anyone help me with setting my container properly to accept incoming TCP connections?
The container hosts an Informix database server, configured to listen on port 9088 (olsoctcp/onsoctcp). It’s working properly but no network connections could be made, only such are possible via shared memory (onipcshm).

The container is being run with exposed ports 9088:9088 and I can verify these are working with ncat and telnet.
This is netstat output from the container where we can see no desired listening port is mentioned:
-bash-4.3$ netstat -an
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 127.0.0.1:10338 0.0.0.0:* LISTEN

So I assume I am doing something wrong in my configuration.
Can somebody help or point me to the proper docs where I can read about it?

Thanks a lot in advance!