传输层 Transport Layer
章节资源
TCP 拥塞控制模拟
发生拥塞时，慢开始门限ssthresh即会设置为出现拥塞时发送方cwnd的一半（通常向下取整），但不能小于2
题目解析
Which is correct about state management for TCP?
A. When the application calls an accept primitive, the TCP entity changes its state from CLOSED to LISTEN and waits for a connection to arrive.
B. Once a segment with only the SYN flag is received, the TCP entity will send a segment with only the ACK flags, and change its state from LISTEN to ESTABLISHED.
C. When the application calls a connect primitive, the TCP entity sends a segment with only the SYN flag, and changes its state from SYN_SENT to ESTABLISHED upon receiving a segment with only the ACK flags. SYN+ACK
D. After sending a segment with only the SYN flag, once it receives a segment with only the SYN flags, the TCP entity will send a segment with SYN+ACK flag and change its state from SYN_SENT to SYN_RCVD.
Outline of a Client-Server Network Interaction over TCP
为什么超时cwnd置1，dup ACK减半？
甲和乙刚建立 TCP 连接，并约定最大段长为 2KB，假设乙总是及时清空缓存，保证接收窗口始终为 20KB，ssthresh 为 16KB，若双向传输时间为 10ms，发送时延忽略不计,且没有发生拥塞的情况，则经过()甲的发送窗口第一次达到20KB。
A. 40ms B. 50ms C. 60ms D.70ms