Stop-and-Wait ARQ:Damaged Frame Sender Receiver Data ACK 1 Data 0 ACK 0 Data 1 Error in NAK Frame 1 Data ACK 1 Flash Time Time
Stop-and-Wait ARQ: Damaged Frame Flash
Stop-and-Wait ARQ:Lost Frame Sender Receiver Data Time out Frame 1 is lost. Data ACK1 Time Time
Stop-and-Wait ARQ: Lost Frame
Stop-and-Wait ARQ:Lost ACK Sender Receiver Data ACK 1 Time out Lost ACK 1 is lost. Data First copy ACK 1 discarded 。 Time Time
Stop-and-Wait ARQ: Lost ACK
SIide Windows Sender window 012345670123456■ Direction Direction This wall moves to the right,frame by frame, This wall moves to the right, when a frame is sent. the size of several frames at a time,when an ACK is received. Receiver window 0I2345670I23456L Direction Direction This wall moves to the This wall moves to the right, right,frame by frame, the size of several frames at when a frame a time,when an is received. ACK is sent
Slide Windows
Sliding Window Example Sender Receiver 0I23456/0I234 0I234560I234- Data 0 02345602Z34e 0I2345时60I23☒4 Data 1 02S34S60234E 0I234560I234F ACK 2 0IZ34时6☑0I☑34 0I234时6☑0I234 Data 2 234560I234 ACK 3 0I23456034 0I234时60234 Data 3 0四Z34时6☑034e 023456023☒4- Data 4 0234的60234 02346☑0234E Data 5 0I2345 ☑0234 0I23456/0IZ34- ACK6 02☑3456☑0234 0U2☑3456☑0234本在
Sliding Window Example