Research On The Virtual Private LAN Based On SUPANET

The network architecture of Single physical layer User-data switching Platform Architecture(SUPA) is promoted by Sichuan Network Communication Key Laboratory, SUPANET is a network which adopt SUPA as its architecture. SUPANET, one kind of backbone network, can provide a service of high speed data exchange. SUPANET aims to the situation that Internet can only provide "Best Effort" service but could not ensure the quality of data transmission service. SUPANET is composed by two platforms, S&M-platform and U-platform. The S&M-platform maintains the protocols of Internet and the U-platform reduces the three layers transmission platforms into single physical layer platform. This network architecture can provide better quality service of data transmission for the users. Because the S&M-platform retains the original Internet protocols stack compatibility in SUPANET, the users can reduce the access costs with no need to change software and hardware or change as little as possible. The virtual line established by SUPANET is formed by a series of Virtual line Identifier (VLI), and the Ethernet-oriented Physical Frame (EPF) carries the MAC frame to finish the data transmission.Based on the backbone network of SUPANET, a new model called Virtual Private LAN Network (VPLN) is presented in this paper to make the hosts belong to different LANs communicate with each other across the SUPANET, which establishes the Virtual Lines(VLs) between them. As a result, hosts can achieve transparent communication with VPLN, i.e. they feel SUPANET WAN absent as if they communicate in the same LAN. The basic idea of transparent communication is that the relative control frames transmission between two LANs are tunneled with EPF in SUPANET, i.e. the frames can be ensured unchanged in the whole process of transmission in SUPANET. Once received an arriving frame, the gateway automatically learns the source MAC address of the frame and its arriving port of gateway, creates the MAC-address-Port mapping table. In the same way, the destination host replies the source host and creates MAC address mapping table. Finally, host users can directly forward the data to the port of the gateway and realize the transparent transmission. Aimed at the S&M-platform and U-platform in SUPANET, the author emphasizes on the work of S&M-platform in this paper, and the primary works is presented as following:(1) A detailed description of point-to-point communication, as well as the point-to-multipoint communication and the process of establishing MAC address mapping table.(2) Design on the organizational structure and the fields of MAC address mapping table, as well as the table maintenance and updating.(3) Description in the process of data transparent transmission between LAN users.(4) Simulation to reveal the feasibility of VPLN.