CE1 CE2 | | SDP1 SDP2 | | _|____ ______ ______ ____|_ ( ) SDPX ( ) SDPU ( ) SDPS ( ) ( N/w1 )------( N/w2 )------( N/w3 )------( N/w4 ) (______) SDPY (______) SDPV (______) SDPT (______)