All-Packets-Based Multi-Rate DDoS Attack Detection Method in ISP Layer

Algorithm 1

All-packets data mapping model via square sketch.

	Input: network packets of t-th period P, f1, f2, m, c
	Output: NCSS of t-th period
(1)	SS, CSS = []
(2)	pool = multiprocessing.Pool(processes = m)
(3)	Bucket_List = pool.map_async(ipsketch, P).get()
(4)	For item in Bucket_List:
(5)	SS[item[0], item[1]] = 1
(6)	End for
(7)	compress SS to obtain CSS
(8)	standardizing CSS to obtain NCSS with formula (6)
	Produce ipsketch(p, f1, f2):
(1)	sip = int(p.sip), dip = int(p.dip)
(2)	i = f1(sip)
(3)	j = f2(dip)
(4)	return i, j