Rdt1.0: reliable transfer over a reliable channel O underlying channel perfectly reliable o no bit erros o no loss of packets O separate FSMs for sender receiver o sender sends data into underlying channel o receiver read data from underlying channel wait for rdt send(data rdt_rcv(packet) wait for call from abov make_pkt(packet, data)(call from below lextract(packet, data) udt_send(packet) deliver data(data) (a)rdt. 0: sending side (b)rdt 1.0: receiving side 3: Transport Layer 3a-133: Transport Layer 3a-13 Rdt1.0: reliable transfer over a reliable channel  underlying channel perfectly reliable  no bit erros  no loss of packets  separate FSMs for sender, receiver:  sender sends data into underlying channel  receiver read data from underlying channel