Internet Service Name Field
The Internet service name field within the /etc/inetd.conf record is simply an Internet service name from the /etc/services file, which was covered in my previous post, "Connection-Oriented Protocols for Clients." You can perform a quick lookup now in the /etc/ services file as follows:
[root@rhel54x64 sgupta]# grep telnet /etc/services
rtelnet 107/tcp # Remote Telnet
There, you will see that the service labeled telnet is configured as a tcp service on port number 23. This is how the inetd daemon determines the port number it must listen for connects on.
Alternatively, you can simply supply a port number.