Study And Development Of Link Aggregation Base On Ethernet

Link aggregation can be used to increase bandwidth and provide link redundancy by getting several physical links together. It is a broadly used and practical technology of the data link layer. Currently the formal standard for link aggregation is IEEE Standard 802.3ad established by IEEE802 Committee, which defines the goals of link aggregation technology, functionality of each module in aggregation sub-layer and the contents of the link Aggregation Control and LACP.In this paper, to meet the different needs of users, link aggregation is divided into two aggregation models, including static and dynamic link aggregation mode based on 802.3ad standard protocol. And on this basis, the design of link aggregation software is given according to modularization thought, which mainly consists of the overall design and sub-module design. The overall design describes the overall data structure design, sub-module division of link aggregation and their mutual relations. In the part of sub-module design, each sub-module design and implementation are detailed, including initialization module, LAGG task module, command processing module, operate key management module, select logic module, LACP module, aggregation management module and driver module etc. Besides, some key algorithms of link aggregation are studied and implemented in this paper. For example, the method of mapping table was used to achieve the dynamic allocation algorithm of operation key. Compared with other methods, this algorithm is simple, fast and easy to be managed and extended; the reference port method was employed to achieve the static selection logic algorithm and dynamic selection logic algorithm, in which the Optimality and Stability were taken into account. Then the functionality and performance of the link aggregation system were tested and analyzed, and the test results show that the function of the presented static and dynamic link aggregation is correct, and that the bandwidth, reliability and stability of the system are enhanced. At last, short summary of this work is given, which describes the inadequate aspect of this paper and the direction for future work.