SSP
PHY
Network interworking over ATM network
Upper layer(s)
Service
specific
protocol
(SSP)
Upper layer(s)
SSCS
CP AAL
ATM
ATM
PHY
PHY
PHY
PHY
Service specific UNI                        Service specific UNI
 Terminal            IWF         ATM network         IWF           Terminal
(transparent to user, “tunneling”)
SSCS
CP AAL
ATM
PHY
SSP
PHY
Service
specific
protocol
(SSP)
PHY