基于GBN的可靠数据传输

******模拟网络环境******：模拟网络环境初始化... ******模拟网络环境******：模拟网络环境启动... 发送方发送报文: seqnum = 0, acknum = -1, checksum = 29556, AAAAAAAAAAAAAAAAAAAA 发送方启动计时器 报文发送后，nextseqnum变为1 接收方正确收到发送方的报文: seqnum = 0, acknum = -1, checksum = 29556, AAAAAAAAAAAAAAAAAAAA ******模拟网络环境******：向上递交给应用层数据：AAAAAAAAAAAAAAAAAAAA 接收方发送确认报文: seqnum = -1, acknum = 0, checksum = 12851, .................... 发送方定时器时间到，回退N步 重发0号报文 重发报文: seqnum = 0, acknum = -1, checksum = 29556, AAAAAAAAAAAAAAAAAAAA 接收方没有正确收到发送方的报文,报文序号不对: seqnum = 0, acknum = -1, checksum = 29556, AAAAAAAAAAAAAAAAAAAA 此时接收方期待的序号是1 接收方重新发送上次的确认报文: seqnum = -1, acknum = 0, checksum = 12851, .................... 发送方滑动窗口内容为 [ * * * * ] 发送方正确收到确认: seqnum = -1, acknum = 0, checksum = 12851, .................... base等于nextseqnum，停止计时器，重新开始发送 发送方发送报文: seqnum = 1, acknum = -1, checksum = 26985, BBBBBBBBBBBBBBBBBBBB 发送方启动计时器 报文发送后，nextseqnum变为2 发送方发送报文: seqnum = 2, acknum = -1, checksum = 24414, CCCCCCCCCCCCCCCCCCCC 报文发送后，nextseqnum变为3 发送方发送报文: seqnum = 3, acknum = -1, checksum = 21843, DDDDDDDDDDDDDDDDDDDD 报文发送后，nextseqnum变为4 发送方发送报文: seqnum = 4, acknum = -1, checksum = 19272, EEEEEEEEEEEEEEEEEEEE 报文发送后，nextseqnum变为5 接收方正确收到发送方的报文: seqnum = 1, acknum = -1, checksum = 26985, BBBBBBBBBBBBBBBBBBBB ******模拟网络环境******：向上递交给应用层数据：BBBBBBBBBBBBBBBBBBBB 接收方发送确认报文: seqnum = -1, acknum = 1, checksum = 12850, .................... 接收方正确收到发送方的报文: seqnum = 2, acknum = -1, checksum = 24414, CCCCCCCCCCCCCCCCCCCC ******模拟网络环境******：向上递交给应用层数据：CCCCCCCCCCCCCCCCCCCC 接收方发送确认报文: seqnum = -1, acknum = 2, checksum = 12849, .................... 发送方滑动窗口内容为 [ 2 3 4 * ] 发送方正确收到确认: seqnum = -1, acknum = 1, checksum = 12850, .................... 接收方正确收到发送方的报文: seqnum = 3, acknum = -1, checksum = 21843, DDDDDDDDDDDDDDDDDDDD ******模拟网络环境******：向上递交给应用层数据：DDDDDDDDDDDDDDDDDDDD 接收方发送确认报文: seqnum = -1, acknum = 3, checksum = 12848, .................... 发送方收到的ACK损坏 接收方正确收到发送方的报文: seqnum = 4, acknum = -1, checksum = 19272, EEEEEEEEEEEEEEEEEEEE ******模拟网络环境******：向上递交给应用层数据：EEEEEEEEEEEEEEEEEEEE 接收方发送确认报文: seqnum = -1, acknum = 4, checksum = 12847, .................... 发送方滑动窗口内容为 [ 4 * * * ] 发送方正确收到确认: seqnum = -1, acknum = 3, checksum = 12848, .................... 发送方收到的ACK损坏 发送方定时器时间到，回退N步 重发4号报文 重发报文: seqnum = 4, acknum = -1, checksum = 19272, EEEEEEEEEEEEEEEEEEEE 接收方没有正确收到发送方的报文,报文序号不对: seqnum = 4, acknum = -1, checksum = 19272, EEEEEEEEEEEEEEEEEEEE 此时接收方期待的序号是5 接收方重新发送上次的确认报文: seqnum = -1, acknum = 4, checksum = 12847, .................... 发送方滑动窗口内容为 [ * * * 0 ] 发送方正确收到确认: seqnum = -1, acknum = 4, checksum = 12847, .................... base等于nextseqnum，停止计时器，重新开始发送 发送方发送报文: seqnum = 5, acknum = -1, checksum = 16701, FFFFFFFFFFFFFFFFFFFF 发送方启动计时器 报文发送后，nextseqnum变为6 发送方发送报文: seqnum = 6, acknum = -1, checksum = 14130, GGGGGGGGGGGGGGGGGGGG 报文发送后，nextseqnum变为7 发送方发送报文: seqnum = 7, acknum = -1, checksum = 11559, HHHHHHHHHHHHHHHHHHHH 报文发送后，nextseqnum变为8 发送方发送报文: seqnum = 8, acknum = -1, checksum = 8988, IIIIIIIIIIIIIIIIIIII 报文发送后，nextseqnum变为9 接收方正确收到发送方的报文: seqnum = 5, acknum = -1, checksum = 16701, FFFFFFFFFFFFFFFFFFFF ******模拟网络环境******：向上递交给应用层数据：FFFFFFFFFFFFFFFFFFFF 接收方发送确认报文: seqnum = -1, acknum = 5, checksum = 12846, .................... 发送方滑动窗口内容为 [ 6 7 8 1 ] 发送方正确收到确认: seqnum = -1, acknum = 5, checksum = 12846, .................... 接收方正确收到发送方的报文: seqnum = 6, acknum = -1, checksum = 14130, GGGGGGGGGGGGGGGGGGGG ******模拟网络环境******：向上递交给应用层数据：GGGGGGGGGGGGGGGGGGGG 接收方发送确认报文: seqnum = -1, acknum = 6, checksum = 12845, .................... 发送方收到的ACK损坏 接收方正确收到发送方的报文: seqnum = 7, acknum = -1, checksum = 11559, HHHHHHHHHHHHHHHHHHHH ******模拟网络环境******：向上递交给应用层数据：HHHHHHHHHHHHHHHHHHHH 接收方发送确认报文: seqnum = -1, acknum = 7, checksum = 12844, .................... 接收方正确收到发送方的报文: seqnum = 8, acknum = -1, checksum = 8988, IIIIIIIIIIIIIIIIIIII ******模拟网络环境******：向上递交给应用层数据：IIIIIIIIIIIIIIIIIIII 接收方发送确认报文: seqnum = -1, acknum = 8, checksum = 12843, .................... 发送方收到的ACK损坏 发送方滑动窗口内容为 [ 1 2 3 4 ] 发送方正确收到确认: seqnum = -1, acknum = 8, checksum = 12843, .................... base等于nextseqnum，停止计时器，重新开始发送 发送方发送报文: seqnum = 9, acknum = -1, checksum = 6417, JJJJJJJJJJJJJJJJJJJJ 发送方启动计时器 报文发送后，nextseqnum变为10 发送方发送报文: seqnum = 10, acknum = -1, checksum = 3846, KKKKKKKKKKKKKKKKKKKK 报文发送后，nextseqnum变为11 发送方发送报文: seqnum = 11, acknum = -1, checksum = 1275, LLLLLLLLLLLLLLLLLLLL 报文发送后，nextseqnum变为12 发送方发送报文: seqnum = 12, acknum = -1, checksum = 64239, MMMMMMMMMMMMMMMMMMMM 报文发送后，nextseqnum变为13 接收方正确收到发送方的报文: seqnum = 9, acknum = -1, checksum = 6417, JJJJJJJJJJJJJJJJJJJJ ******模拟网络环境******：向上递交给应用层数据：JJJJJJJJJJJJJJJJJJJJ 接收方发送确认报文: seqnum = -1, acknum = 9, checksum = 12842, .................... 发送方收到的ACK损坏 接收方正确收到发送方的报文: seqnum = 10, acknum = -1, checksum = 3846, KKKKKKKKKKKKKKKKKKKK ******模拟网络环境******：向上递交给应用层数据：KKKKKKKKKKKKKKKKKKKK 接收方发送确认报文: seqnum = -1, acknum = 10, checksum = 12841, .................... 接收方没有正确收到发送方的报文,数据校验错误: seqnum = 12, acknum = -1, checksum = 64239, NMMMMMMMMMMMMMMMMMMM 接收方重新发送上次的确认报文: seqnum = -1, acknum = 10, checksum = 12841, .................... 发送方滑动窗口内容为 [ 11 12 5 6 ] 发送方正确收到确认: seqnum = -1, acknum = 10, checksum = 12841, .................... 发送方没有正确收到确认,序号不满足要求，继续等待 发送方定时器时间到，回退N步 重发11号报文 重发报文: seqnum = 11, acknum = -1, checksum = 1275, LLLLLLLLLLLLLLLLLLLL 重发12号报文 重发报文: seqnum = 12, acknum = -1, checksum = 64239, MMMMMMMMMMMMMMMMMMMM 接收方没有正确收到发送方的报文,报文序号不对: seqnum = 12, acknum = -1, checksum = 64239, MMMMMMMMMMMMMMMMMMMM 此时接收方期待的序号是11 接收方重新发送上次的确认报文: seqnum = -1, acknum = 10, checksum = 12841, .................... 发送方没有正确收到确认,序号不满足要求，继续等待 发送方定时器时间到，回退N步 重发11号报文 重发报文: seqnum = 11, acknum = -1, checksum = 1275, LLLLLLLLLLLLLLLLLLLL 重发12号报文 重发报文: seqnum = 12, acknum = -1, checksum = 64239, MMMMMMMMMMMMMMMMMMMM 接收方正确收到发送方的报文: seqnum = 11, acknum = -1, checksum = 1275, LLLLLLLLLLLLLLLLLLLL ******模拟网络环境******：向上递交给应用层数据：LLLLLLLLLLLLLLLLLLLL 接收方发送确认报文: seqnum = -1, acknum = 11, checksum = 12840, .................... 发送方滑动窗口内容为 [ 12 5 6 7 ] 发送方正确收到确认: seqnum = -1, acknum = 11, checksum = 12840, .................... 接收方正确收到发送方的报文: seqnum = 12, acknum = -1, checksum = 64239, MMMMMMMMMMMMMMMMMMMM ******模拟网络环境******：向上递交给应用层数据：MMMMMMMMMMMMMMMMMMMM 接收方发送确认报文: seqnum = -1, acknum = 12, checksum = 12839, .................... 发送方滑动窗口内容为 [ 5 6 7 8 ] 发送方正确收到确认: seqnum = -1, acknum = 12, checksum = 12839, .................... base等于nextseqnum，停止计时器，重新开始发送 发送方发送报文: seqnum = 13, acknum = -1, checksum = 61668, NNNNNNNNNNNNNNNNNNNN 发送方启动计时器 报文发送后，nextseqnum变为14 发送方发送报文: seqnum = 14, a