Request Numbers Are Required On ACKs To Distinguish Packet ACKed 0 packet 0 timeout o packet 0 1 packet 1 ACK ACK Packet o accepted REQUEST NUMBERS Instead of sending"ack"or "nak", the receiver sends the number of the packet currently awaited Sequence numbers and request numbers can be sent modulo 2 This works correctly assuming that 1)Frames travel in order( FCFS)on links 2)The CrC never fails to detect errors 3)The system is correctly initialized Eytan modianoRequest Numbers Are Required O n ACKs To Distinguish Packet ACKed ACK ACK 0 ut 0 ? packet 0 timeo 0 packet 1 packet 1 Packet 0 accepted • REQUEST NUMBERS: – Instead of sending "ack" or "nak", the rec eiver sends the number of the packet c urrently awaited. – Sequence numbers and request numbers can be sent modulo 2. Thi s works correctly assuming that 1) Frames travel in order (FCFS) on links 2) The CRC never fails to detect errors 3) The system is correctly initialized. Eyt an Modiano 5