The problem

You have deployed a device in the field, on your customer premises. Months passes and you need to access it again. Neither you, nor your customer have any idea what IP address it has right now. You just know that you have SSH listening on non-standard port like 222.

The solution

nmap is a great tool to help you here. Assuming you have access to some node of your customer network, or you have a VPN access to this network, just invoke:

nmap -p 222 --open -sV 192.168.0.1-255

This will look in subnet 192.168.0.0/24 for devices that have port 222 open, and it is an SSH listening there.