Cloud computing is becoming more and more popular in IT industry nowadays. Those famous companies including Amazon, IBM, HP, Google and Microsoft are creating and deploying Clouds in various locations around the world. Technically, Cloud Computing refers to both the applications delivered as services over the Internet. In the cloud, there might be tens of thousands or even more users accessing resource simultaneously, which give an extremely high pressure on the cloud. An effective traffic control mechanism which can both control the network traffic and make full use of network bandwidth is Hierarchical Token Buckets (HTB). It is used to control the outbound bandwidth on a given link. HTB ensures that the traffic rate for each class is at least the amount assigned to it. And the main difference between HTB and other queue discipline is when a class requests less than the amount assigned, the remaining bandwidth can be “borrowed” by other classes which request more. This solution is very suitable for service provider such as cloud computing: the basic requirements are guaranteed when there are many concurrent users (based on their payment), and when there are free resources, users can enjoy a better experience. Unfortunately, the existing HTB implementation can afford 0.5Gbps speed at most, making it impossible to be utilized in the cloud. With the popularity of multi-core processors, a possible improvement is making the original sequential HTB into parallel, which might raise its processing speed.