Pete Najarian, co-founder of OptionMonster.Riverbed Technology ( RVBD) options are drawing heavy call activity ahead of its earnings report next week. The average daily volume for Riverbed Technology option contracts is 3,558, but more than 13,000 calls had traded in the first 100 minutes of today's session. The early buying began with the May 17.50 calls and then spilled into the May 20 strike as well, according to OptionMonster's real-time tracking systems. By mid-afternoon more than 15,200 of the May 17.50 calls and 4,700 of the May 20 had changed hands against relatively minuscule open interest of 273 and 11 contracts, respectively. Riverbed Technology stock is up about 2% on the day to $15.45. The company, which provides technologies designed to improve network speeds, is scheduled to release its quarterly earnings after the market closes next Thursday, April 23. According to a report from a William Blair analyst, sentiment is starting to improve after a dismal start to the year for those in the data network equipment business. The writer has a long call spread in Riverbed Technology.