Cloud services are booming. It is expected that more than 90% of the business will be deployed in the cloud in the future. Many operators have taken cloud service as a key business strategy. While, traditional networks still face many challenges to bearer cloud services, for example traffic between data centers(DC) grows very fast, unpredictable, and so on. High capacity backbone router is necessary to deal with the traffic repaid growth and agile solution is needed to deal with the unpredictable traffic between DCs. IP + optical synergy solution can achieve IP layer + optical layer collaborative planning to enhance network resources efficiency. Glen Hunt, principal analyst of Global Telecom Technology and Software, shared with us his opinion on the cloud-driven backbone network evolution.