Research Of QinQ Technology And Implemention On BRAS

After several transforming periods, the IP broadband network has formed into three levels as the core layer, service control layer and access layer. Since the diversity of business, the development of service control layer is towards multi-service edge. The structure of the multi-service edge need access network has the ability of precise identification of users and service identification. Besides, the different service should be classified appropriately to assure the correct transfer of data-flow.As the expansion of the 802.1Q protocol, QinQ is to add a VLAN tag to 802.1Q VLAN, expands the VLAN space and overcome the issue of quantity in the VLAN development. Meanwhile, QinQ encapsulation and termination modes tend to diversity to cater for the development of the MAN. QinQ also brings us an effective solution of precise identification of users and service identification. And now, QinQ is widely applied for the intensive operation of carriers.Besides studying QinQ theory and its application in MAN, this thesis also introduces several common networking solutions used in MAN. Based on the actual demand in network, we add a function of PPPoE, IP supporting QinQ to a certain BRAS equipment. With the feature of QinQ precise identification of users and service identification, a QoS allocation strategy is proposed which named as user-based QoS.Firstly, based on the analysis of software architecture of router platform and QinQ terminal needs, data structure of the VLAN module has been designed. By designing user interface and completing the process of QinQ configuration order, the maintenance of VLAN of Ethernet subinterface information has been implemented.Secondly, through the analysis of data flow and control flow among different modules such as VLAN, PPPoE, transfer, adjacent table and ARP, the receiving and transmitting process of Layer 3 Ethernet subinterface have been achieved. Finally, through analyzing the consultation process of existing modules like PPPoE, PPP, AAA, and QoS, the data structure of User Control Block (uscb) has been designed and used for recording users'QoS information. And then user-based QoS has been achieved.Through this project, the previous BRAS equipment could support the QinQ and be used in QinQ network environment. The issue of precise positioning of users and service identification and isolation could also be solved. Further more, this project provides a flexible QoS allocation strategy .All of these enhance the network management and consequentially adapt to the MAN development.