ipg/ewma的意思是什么？

Question

在ping -f 127.0.0.1的结果中一个ipg/ewma的结果参数，查过很多资料，没有找到一个确定的定义说明，想知道两个参数的含义是什么？

在网上搜索到过关于ipg的一个公式，但不太理解是什么意思。
int ipg = (1000000 * (long long) tv.tv_sec + tv.tv_usec) / (ntransmitted-1);
printf ( "ipg / EWMA% d.% 03d /% d.% 03d ms"
ipg / 1000, ipg% 1000 rtt / 8000, (rtt / 8)% 1000);

ipg的意思是the Interpacket Gap，在Wikipedia上的意思是下面这个：
Ethernet devices must allow a minimum idle period between transmission of Ethernet frames known as the interframe gap (IFG) or interpacket gap (IPG). It provides a brief recovery time between frames to allow devices to prepare for reception of the next frame. The minimum interframe gap is 96 bit times (the time it takes to transmit 96 bits of raw data on the medium), which is 9.6 μs for 10 Mbit/s Ethernet, 960 ns for 100 Mbit/s (fast) Ethernet, and 96 ns for 1 Gbit/s (gigabit) Ethernet.
ewma的意思是Exponential Weighted Moving Average，在Wikipedia上的意思是下面这个：
It stands for Exponential Weight Moving Average. It's a way of using a continuously-functioning output (say a long-running fping/ping -f) to get more-relevant results. For a long-running ping, all old values no matter how old are still used for computing the min/max/avg but the use of EWMA gives you more relevant results for more recent pings.
但具体的含义还是不太清晰。

Answer 1

IPG/EWMA是Internet Protocol Group/Exponentially Weighted Moving Average的缩写，它是一种网络测量技术，用于测量网络中的延迟和丢包率。IPG/EWMA的工作原理是，它会计算每个数据包的延迟，并使用指数加权移动平均（EWMA）算法来计算网络的平均延迟。它还可以计算网络中的丢包率，以及网络中的抖动（jitter）。