Calculate BDP value and wnd value

background

Optimize the network , Need to adjust wnd The best value of window value . But there is no algorithm that is particularly easy to understand . The example given is completely out of line with the result of your own calculation . Burst the liver for several nights , Finally put BDP and Window value I understand the calculation method of , The network efficiency has indeed been improved .
I hope this blog can help Xiaobai understand the calculation process , Help people in need .

BDP Value algorithm

Reference resources : https://docs.oracle.com/cd/E56344_01/html/E53803/gnkor.html
BDP brief introduction :
Bandwidth delay product (bandwidth delay product, BDP)

computing method ：
Bandwidth-Delay Product = delay * bandwidth

Bandwidth delay product = Time delay * bandwidth

BDP = Broadband _ byte _B * Time delay _s

sndwnd and rcvwnd Algorithm

sndwnd Is the send window , Corresponding upload ;
rcvwnd Is the receiving window , Corresponding download .

computing method :
Window value _ byte _B = BDP / MTU

Use python Calculate window value

Even if the calculation method is given , I'll feel dizzy for the first time , Simply write it directly python Script , If you need it, take it and calculate it directly . Personally, I think the notes are fairly clear , I hope those who need it can understand it .

"""  Refer to the formula : BDP =  Broadband _ byte _B *  Time delay _s  Window value _ byte _B = BDP / MTU """

def wnd( bandwidth _ Megabits _Mbit,  Time delay _s, MTU):
    """ #  Calculate window value _ byte _B :param  bandwidth _ Megabits _Mbit:  Incoming bandwidth value ( Small b) :param  Time delay _s:  Incoming delay (s) :param MTU:  Incorporation mtu value ( It's usually 1400) :return:  Return the calculated window value _ byte _B """
    # 128 = 1024 / 8 # kBtye conversion Mbit The value of is 128
    #  Broadband _ kilobytes _kBtye =  bandwidth _ Megabits _Mbit * 128
     Broadband _ kilobytes _kBtye =  bandwidth _ Megabits _Mbit * 1024 / 8

    #  Broadband _ byte _B  and   Broadband _ kilobytes _kBtye  The conversion unit of is 1024
     Broadband _ byte _B =  Broadband _ kilobytes _kBtye * 1024
    BDP =  Broadband _ byte _B *  Time delay _s
    #  Window value _ byte _B In bytes _B
     Window value _ byte _B = BDP / MTU
    print(f"BDP The value is :{
      int(BDP)}")
    print(f" The window value is :{
      int( Window value _ byte _B)}")


if __name__ == '__main__':
     bandwidth _ Megabits _Mbit = 500
     Time delay _s = 0.125
    MTU = 1500
    #  Print window values _ byte _B
    wnd( bandwidth _ Megabits _Mbit,  Time delay _s, MTU)