which port Do i need to open in Perl container for connecting oracle db container

Hi i am running oracle db in a container with port 1521 exposed .I have another perl container .
This is what docker ps shows

CONTAINER ID   NAME        IMAGE             COMMAND                  CREATED             STATUS                    PORTS
bb8686d87c66    perl      perl:5.16         "/usr/bin/supervisor…"   5 minutes ago       Up 5 minutes  
9e37dff4c19e    oracle    oracle:   "/bin/sh -c 'exec $O…"   41 hours ago        Up 41 hours (healthy)>1521/tcp , 5500/tcp   oracle        

i am able to ping from perl container to oracle container. But i can’t do the same from oracle to perl.
I am not exposing ports in perl image . Do i need to expose any port for this ??

I have a link.conf file for perl conatiner which connect oracle db with perl

 LINKS=' --link oracle:oracle'

Finally i want to use a perl script in perl container to connect to the schema.can i do it with my present configurations ??

Source: StackOverflow