How to Identify Port to a Process?

You have to execute netstat -tulnp as root. Otherwise you get the - instead of the process name.

This is what the manpage says:

PID/Program name
   Slash-separated pair of the process id (PID) and process name of the process that owns the socket.  --program causes  this  column
   to  be  included.   You will also need superuser privileges to see this information on sockets you don't own.  This identification
   information is not yet available for IPX sockets.

With one exception: portmapper See this

You can use nmap with -sV option to determine service info:

# nmap -sV -p 35670 localhost

Why is rpc.lockd obscured from netstat/lsof output?