Thanks for the reminder.
My microcore doesn't have 'ab' command. Maybe it's the smallest package in tinycore Linux.
I did find tce-load tool and used it to download and installed "sshd". It's nice tool! So this solved my remote login issue.
Since my box is diskless and I booted everything into RAM so there is no persistent storage for my sshd files. If sshd should survive the reboots, then I will have to package them into the core.gz. I haven't found anything in wiki how to do this yet. Please let me know if you have a link.
David