ATMATM (Asynchronous Transfer Mode)

.. ATMPacket Networks Cell Networks ATMCell ATM

ATM ATM ITU backbone software

Packet Networks Cell NetworksPacket Networks MUX

Packet Network Cell NetworkCell Networks MUX

ATM ATM cell-switched networks end points user-to-network interface (UNI) switch network-to-network interface (NNI)

ATM ATM Transmission Path (TP) TP (Virtual Path: VP) 2 (Virtual Circuit: VC)

ATM switch I switch IV switch II 2

ATM cell cell Virtual Path Identifier (VPI)Virtual Circuit Identifier (VCI)VPIVCIVPIVCI8 bits16 bits12 bits16 bitsUNI InterfaceNNI Interface

Cell ATM ATM Cell 53 (header) 5 (payload) 48

VCIHeaderPayloadVPIVCI5 Bytes48 Bytes53 Bytes

ATM ATM 3 Application Adaptation Layer (AAL)ATM LayerPhysical LayerApplication Adaptation Layer(AAL)ATM LayerPhysical

ATMApplication Adaptation Layer (AAL) ATM ATMATM Layer Physical Layer