[qi:101] Riverbed Technology (s RVBD), one of the big players in wide area network optimization, today acquired network management software maker Mazu Networks for about $25 million in cash with some incentives based on sales performance. For Riverbed, this is a bargain-basement way of adding features that would help its customers monitor video and VoIP traffic on their enterprise networks. Mazu makes network behavior analysis software. The deal is not such a good one for the VCs, who pumped more than $40 million into the company. Investors include Greylock, Benchmark Capital, Matrix Partners and Starvest. As a footnote, if the Mazu team manages to get $35 million in sales, it gets another $22 million in cash. According to UBS, Mazu had about $18 million in bookings over past 12 months.