The Netgraph Architecture And Its Application To Achieve

For the recent several years, with ever fast development of the network protocol standards and the continuously emergence of new high-speed network applications, the hierarchical architecture of traditional TCP/IP protocol stack gradually become insufficient for the new requirements, especially in the occasions of high throughput. However, as the traditional TCP/IP protocol stack is generally regarded stable and has been widely deployed in the current Internet, it is of high price to totally abandon the current architecture. Under this circumstance, a brand-new architecture, which is named netgraph, comes into horizon.Besides the guaranty of the high efficient data clustering, netgraph architecture also has substantially good compatibility with the TCP/IP protocol stack in the currently widely-used operation systems. Therefore, it can provide people a new type of developing platform without interferring the current TCP/IP protocol stack. Especially in the area of embedded system network applications, how to increase data handling ability of the equipments with a low price has aroused common attention. As a result, on the basis of insight analysis, this thesis proposes the use of netgraph architecture in the development of embedded system network applications, and we fully verify the feasibility and the scalability of this architecture.The structure of this thesis is organized as following: the architecture of eCos is introduced firstly. The design and the principle of netgraph architecture are introduced secondly, and the low-layer implements of netgraph, as well as the communication mechanisms between the netgraph sub-system and the other core modules in the system, are articulated. Thirdly, combined with its applications, the developments of network protocols and network applications based on netgraph architecture are expounded. In this step, the feasibility of the netgraph architecture applied to embedded system is illustrated according to the PPPOE client implemented with it. And the scalability of netgraph architecture is explained through the VLAN application expanded by PPPOE clients. At last, the research results and the drawbacks are summarized.