tcp拥塞控制四种算法
时间: 2023-08-18 20:51:03 浏览: 69
TCP拥塞控制的四种算法分别是:
1. 慢启动(Slow Start):在开始时,发送方只发送一个分组,然后等待确认。如果确认到达,则发送方将窗口大小加倍,然后发送两个分组,并等待确认。这个过程将持续,直到窗口大小达到某个阈值。
2. 拥塞避免(Congestion Avoidance):在窗口大小达到一定阈值之后,发送方将进入拥塞避免阶段。在这个阶段,发送方将以线性增量增加窗口大小,而不是指数级增加。
3. 快速重传(Fast Retransmit):如果发送方在一定时间内没有收到确认,它将重传最先未被确认的分组。但是,如果发送方收到三个重复的确认,则它将执行快速重传,而不是等待超时。这个过程将加快数据传输的速度。
4. 快速恢复(Fast Recovery):在快速重传后,发送方将进入快速恢复阶段。在这个阶段,发送方将以线性增量增加窗口大小,而不是重新执行慢启动。这个过程将避免数据传输速度的下降。
相关问题
tcp拥塞控制四种算法代码
以下是TCP拥塞控制四种算法的伪代码实现:
1. 慢启动(Slow Start):
```
while (window_size < threshold) {
send_packet();
if (ack_received()) {
window_size *= 2;
}
}
```
2. 拥塞避免(Congestion Avoidance):
```
while (true) {
send_packet();
if (ack_received()) {
window_size += 1 / window_size;
}
}
```
3. 快速重传(Fast Retransmit):
```
while (true) {
send_packet();
if (ack_received()) {
// do nothing
} else if (duplicate_ack_received()) {
retransmit_packet();
} else {
// timeout occurred
retransmit_packet();
}
}
```
4. 快速恢复(Fast Recovery):
```
while (true) {
send_packet();
if (ack_received()) {
if (window_size < threshold) {
window_size += 1;
} else {
window_size += 1 / window_size;
}
} else if (duplicate_ack_received()) {
window_size /= 2;
} else {
// timeout occurred
threshold = window_size / 2;
window_size = 1;
}
}
```
请注意,这只是伪代码实现,实际实现可能会有所不同,并且可能涉及更多的细节和错误处理。
tcp拥塞控制四种算法代码c++
以下是TCP拥塞控制四种算法的C++代码实现:
1. 慢启动(Slow Start):
```
int window_size = 1;
int threshold = 64;
while (window_size < threshold) {
send_packet();
if (ack_received()) {
window_size *= 2;
} else {
threshold = window_size / 2;
window_size = 1;
}
}
```
2. 拥塞避免(Congestion Avoidance):
```
int window_size = 64;
while (true) {
send_packet();
if (ack_received()) {
window_size += 1 / window_size;
} else {
threshold = window_size / 2;
window_size = 1;
}
}
```
3. 快速重传(Fast Retransmit):
```
int window_size = 64;
while (true) {
send_packet();
if (ack_received()) {
// do nothing
} else if (duplicate_ack_received()) {
retransmit_packet();
} else {
// timeout occurred
retransmit_packet();
threshold = window_size / 2;
window_size = 1;
}
}
```
4. 快速恢复(Fast Recovery):
```
int window_size = threshold;
while (true) {
send_packet();
if (ack_received()) {
if (window_size < threshold) {
window_size += 1;
} else {
window_size += 1 / window_size;
}
} else if (duplicate_ack_received()) {
window_size /= 2;
} else {
// timeout occurred
threshold = window_size / 2;
window_size = 1;
}
}
```
请注意,这只是伪代码实现,实际实现可能会有所不同,并且可能涉及更多的细节和错误处理。