Differentiated Services, Ip-based Dslam System Qos

With today's fast development of the wide band synthesis service, IP DSLAM turns on in the network as DSL the important acess technology, is playing an important role which links the preceding with the following. Providing differentiated service to different types of traffic on IP DSLAM can realize end-to-end QoS in the mufti-services service network, and avoid IP DSLAM becoming the QoS bottleneck in the network, is a topic which is worth studying.Differentiated QoS implementation of IP DSLAM system is the main investigation object of this paper. Based on the current research of QoS theories and technologies, it is proposed a QoS guarantee solution of priority-based differentiated service implementation architecture and forwarding module, which creatively analyzes the process of differentiated QoS deployment on IP DSLAM system. Main contents are as follows:1. Investigation of QoS architecture of IP DSLAM system, and analysis of User Priority defined in IEEE802.1p standard and DiffServ module suggested by IETF group, which are both applied practically to IP DSLAM system multi-traffic access module and PHB-based QoS core forwarding strategy.2. Detailed description of implementation of IP DSALM QoS function, including packet-priority-based QoS attributes marking sub-module and QoS-attribute-based queues scheduling sub-module on output port. The QoS marking algorithm and queue scheduling strategy is chiefly investigated and analyzed. The most quintessential part of forwarding packets is on the foundation of buffer management, which is described and illuminate as test cases.3. Itemization of QoS differentiated function test results on real device integrated environment of IP DSALM system,which verified the correctness of systemic QoS implementation. Compared explanation of packets discarding is raised to summarize the buffers and descriptors related typical issues, and to draw lessons to handle such complex problems.