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问题:拥塞控制慢开始算法拥塞窗口的初始值是多少？

根据RFC文档:

IW, the initial value of cwnd, MUST be set using the following

guidelines as an upper bound.

If SMSS > 2190 bytes:

IW = 2 * SMSS bytes and MUST NOT be more than 2 segments

If (SMSS > 1095 bytes) and (SMSS <= 2190 bytes):

IW = 3 * SMSS bytes and MUST NOT be more than 3 segments

if SMSS <= 1095 bytes:

IW = 4 * SMSS bytes and MUST NOT be more than 4 segments

cwnd拥塞窗口初始值一般为2-4个smss大小

mss–最大报文段

SMSS(Sender’s MSS),发送方最大报文段

SYN段中携带的MSS选项值实际上就是本端网络设备的MTU。

MTU是指数据链路层向网络层发数据的最大传输单元。

mtu取决于网卡路由器，Linux可用ifconfig命令查看