W5300 tcp open command

I was working with w5300 interfaced with dsp. Implemented tcp/ip protocol related firmware, it was working fine with pc to w5300 communication. We have used netcat tool for port opn command.i want to know exact meaning of this port open command. Because we need to interface w5300 other end wih lpc1788 + lan8720 phuy instead of pc. So i need to send port open command using this other chip(lpc1788 in lower layers). But with udp we dont need open port command right? But there is a chance to packet loss. Thats why we need ro use tcp/ip. Without pc,by using lowerlayers protocol, how to send open, listen, connect, etc
Thanks & regards,

Can we communicate with w5300 using another devices(otherthan PC)? or We must use pc only at other end? And one more thing is we need to use in TCP/IP mode only. Is there any possibility?
thanks & regards,