Research On Single-layer User-data Switching Platform Architecture

Internet was developed for text-oriented network applications when line transmission rate was very low while error rate was very high. Moreover, U-platform (User-data switching platform) in Internet architecture has congenital defects of complex three-layer structure, low user-data transfer efficiency and bad QoS (Quality of Service) provisioning. With the development of DWDM optical fiber transmission techniques in very high-speed transmission rate and low error rate, a novel DWDM-based backbone network architecture called "SUPA"(Single-layer User-data switching Platform Architecture) is developed at SC-Netcom Lab (Sichuan Network Communication Key Laboratory) to prevent these defects.By re-clarifying out-of-band signaling concept in the context of networking, SUPA separates U-platform from S&M-platform (Signaling&Management Platform), and simplify U-platform into a single physical layer to make it as a basis of backbone nodes for high-speed and high-efficient switching. Meanwhile, oriented to the most popular Ethernet, EPFTS (Ethernet-oriented Physical Frame Timeslot Switching) technology is also promoted at SC-Netcom Lab to combine multiplexing of DWDM physical channel (wavelength) with switching fabrics of switch nodes for greatly improving transfer efficiency, to support Virtual Line connection service for end-users with embedded QoS mechanism in physical layer. The most advantage of SUPA is the integration of the out-of-band signaling and EPFTS over DWDM to support end-to-end QoS service for end-users. Therefore, SUPANET (Single-layer User-data switching Platform Architecture Network) can support audio, video and data services in a single network in order to meet the merged network requirements of NGI (Next Generation Internet) or NGN (Next Generation Network).The author firstly analyzes the challenges of high-speed switching, QoS provisioning, security and access diversity in current Internet, and comprehensively analyzes the domestic and overseas reserach status of NGI/NGN, proposes a basic development approach to cope with the technical challenges in NGI architecture. With the rethinking of inadequacy of orthodox OSI/RM model and current Internet architecture, the author analyzes requirements and general objectives of NGI, provides a new representation of Internet architecture with out-of-band signaling concept, points out that the simplification should be carried out in both platforms (U-Platform and S&M-platform), and proposes a refined model ONAS/RM (Open Network Application Service/Reference Model) to extend OSI/RM architecture to meet the requirements of application virtualization and oriented-service in future networks. To realize the above-mentioned NGI general objectives, ONAS/RM is defined as a new three-layer architecture including Application Supporting Layer, Transport Layer and Substrate Layer.Moreover, in contrast to "evolutionary" or "revolutionary" strategy, SC-Netcom Lab proposes a "BSF-OES"(Backbone Substrate First, Outwards Expansion Second) development strategy to solve the problems in NGI. This strategy is based on the vision of communication world where future backbone networks will be based on low error-rate DWDM with very high bit rates; while access networks will be based on diverse communications techniques possibly with high error-rates. Introduction of the out-of-band signaling enables separation of U-platform from S&M-platform and consequently reduces the U-platform to minimal, especially over optical fiber communications in backbone. Based on consideration of interoperability with Internet and smooth migration from Internet, this strategy implies first to focus on building a thin substrate to cope with high-speed switching problem with embedded QoS mechanism and security measures, and outwards expansion will be done only when backbone technologies are fledged and wherever applicable. In this thesis, SUPA is used as a framework of NGI backbone network architecture to demonstrate feasibility of such strategy and how to cope with technical challenges, to protect investments, and to make smooth migration to NGI. According to BSF-OES strategy, the author also emphasizes three phases of the research and development strategy to EPFTS-based frameworks of SUPA.SUPA phase1is about preliminary study on SUPA focusing on EPFTS in U-platform and remaining existing Internet protocol stacks in S&M-platform with necessary enhancement. The author summarizes the architecture developed in SUPA phase1, discusses the related kernel technique results to demonstrate feasibility of SUPA development strategy, and analyzes the defects in phase1and the necessity of phase2researches and experiments. As a result, the author proposes SUPA phase2as EPFTS based substrate researches and experiments for both U-platform and S&M-platform with further refinement of SUPA. However, SUPA phase3is for further study aiming for a future network model as desribed in ONAS/RM model.As only U-platform is supported by EPFTS in SUPA phase1, the author proposes that S&M-platform in SUPA phase2should be also supported by EPFTS to further simplfy the S&M-platform into a4-layer end-system model. Meanwhile, the author adopts a reconfigurable architecture design of combining out-of-band signaling with in-band signaling to make further refinement of SUPA. For efficiency, it is the inherent design in SUPA that there is separation between S&M-platform and U-platform generically to simplify U-platform with out-of-band signaling, while there is enhancement of functions such as OAM (Operation Administration and Maintenance) in both platforms separately to transfer short "in-band" Signaling&Management informations with in-band signaling.Taking SUPA phase2as the research emphases in this thesis, the author carried out overall study of the architecture developed in phase2. The author puts forward and develops a systematic framework of phase2, with emphasis on EPFTS-based S&M-platform framework and OAM. The author lays stress on discussing S&M-platform and its interfaces, signaling procedures and signaling massage transformation processes, as well as in-band OAM sublayer over EPF (Ethernet-oriented Physical Frame) sublayer in U-platform. Based on finished research on QoS ensurement system of SUPA phase1, the author continues to carry out research on QoS ensurement system in SUPA phase2, defines related SUPA services, protocols and interfaces. The author discusses problems of reliability, availability and OAM, emphasizes on research of U-platform OAM functions and mechanisms in SUPANET, several mechanisms proposed for re-routed protection switch and inband OAM-based protection switch are proved feasible in simulation experiments. Finally, the author sums up the main works and innovations, which results lay a foundation for further research on SUPA frameworks.