With the arrival of Big Data Era, properly utilizing the power of big data is becoming essential for the strength and competitiveness of businesses and organizations. We are facing grand challenges from big data from different perspectives, such as processing, communication, security, and privacy. In this talk, we will look at the big data problems from a unique perspective from the network level. We will discuss the challenges in classifying big network traffic data and our solutions to the challenges. The significance of the research lies in the fact that the exponentially increasing Internet traffic has become an extremely difficult big data analytic problem. In this talk, we propose a series of novel approaches for traffic classification, which can improve the classification performance effectively by incorporating correlated information into the classification process. We analyze the new classification approaches and their performance benefit from both theoretical and empirical perspectives.