Layer		Alternative #1



Application	TFTP		--- PXELINUX code

Transport	UDP     	--+
                          	  |
Network		IP        	  +-- From PXE ROM
                          	  |
Data link	UNDI    	--+



Layer		Alternative #2



Application	TFTP, HTTP, ... --- PXELINUX code

Transport	UDP, TCP        --+
				  +-- lwIP
Network		IP        	--+  
                        
Data link	UNDI		--- From PXE ROM