Research On Hiberarchy QoS Based On DiffServ

After the 90's of the 20th century, the computer network has got a dazzling evolution.Noboby will doubt at its achievement and the potential.It's implicit that the operation on IP is diversed and increased quickly. More and more person begin to use it, and its development speed has by far beyond the Internet technology and the network devices. For such reason, the network resources have become costly. So, how to utilize them sufficiently, how to give our user a high quality service over IP network become a big question. The appearance of IP QoS can resolve the problem.IP QoS is the quality of service of IP network, also the performance of the IP data stream when they through the network. It is a task for the IP QoS to provide the certain users with the reliable service to the certain requirement. It is judged by such parameter as Usability, Latency, Jitter, the Ratio of discard, and so on.With an expansion of the scale of customers and an increasement of the operation, a lot of new operations over the IP network have become to implement, just like VoIP, IPTV. At the same time, the carriers want to set up network of next generation based on the present access network. It is demanded that the network devices not only have the ability to differentiate the flow of operations more meticulously, but also are able to provide the uniform management and hiberarchy scheduler of the transmission objects such as multi-users, multi-operations, multi-flows. The normal QoS policy can not meet the demand, and a new policy of hiberarchy QoS comes into being.This paper made a deep study in DiffServ architecture and the key technology such as traffic policing, traffic shaping, congest management, congest avoiding, data packets classifying.This provides the theory basis of raising the model of hiberarchy QoS based on the outline of QoS technology. Alongwith the study on the DiffServ architecture, this paper has made a detailed description of the realization of it in network devices.At last, verified the performance and the hiberarchy scheduler effect of the hiberarchy QoS policy through the test and made a comparison between normal QoS policy and hiberarchy QoS policy based on the experiment of the traffic policing, the congest avoiding and the congest management.