Hi...

I'm new in linux and barely finished my first Ubuntu server installation.
I need this server as a authentication server to grant console access to some serial-port based equipment via serial over TCP/IP. I've got the TCP/IP-to-serial switch but it doesn't have any authentication mechanism.

My scenario is to create user accounts in the server and connect it to internet.

Users from the internet can access the particular serial device just by telneting this server ip address with a specific port number and they directly forwarded to the device after they pass authentication.

My requirement is:
1. User should login first to this server before can access the serial devices.
2. Each user has different privileges which are based on date, time and the serial port they have access to.
3. the users must no have any other access except that.

Can this server build-in user account able to manage this scenario or I have to install additional authentication software such as Radius or tacac?

Thank you