Research On QoS Negotiation Protocol In SUPANET

Internet was developed for text-oriented network applications when line transmission rate was very low while Bit Error Rate (BER) was very high. Such "best effort service" in fact was quite satisfactory for text oriented application transmission, but not suitable for stream-oriented traffic for its low efficiency and QoS dependency on lower layers in its 3-layer user-data switching platform. Unfortunately, most existing low level protocols were not catered for QoS insured service;therefore it becomes more and more difficult to satisfy requirements of important QoS parameters (e.g. throughput, transit delay, and variation of transit delay, i.e. jitters) for audio and video traffic with higher and higher line-speed.With rapid progress in optical techniques, especially DWDM, lambda rate has been raised to 40/80/160 Gbps and bit rate over a single fiber is approaching to Tbps. In other words, communication technique is fledged for converging existing telephone-switched networks, cable TV networks, and computer networks into an integrated digitalized and packet-switched network but network architectures such as that of Internet are not. This is exactly the reason why RSVP, Differentiated Service, Integrated Service, and MPLS recommended by IETF were not so successful in solving QoS problems.To solve these problems, Sichuan Network Communication Technology Key Laboratory, Southwest Jiaotong University has defined a new network architecture called SUPA (Single physical layer User-data transfer & switching Platform Architecture). The core technique enabling SUPA is called EPFTS (Ethernet-oriented Physical Frame Timeslot Switching), which provides a granular multiplexing and switching capability between lambdas or communication lines to form an integrated physical layer U-platform. Therefore, SUPANET is composed of two platforms, the U-platform and S&M-platform, which is an enhancement to existing Internet protocol stacks to enable interoperability with Internet.QoS insurance system in SUAPNET consists of two sets of mechanisms: QoS Negotiation Protocol (QoSNP), QoS-based Lambda Routing Information Protocol (λQoS-RIP), Traffic Monitoring and Exchange Protocol (TMEP),and Call Admission Control in S&M-platform and those in U-platform such as User-data Admission Control (UAC), Media Quota assignment Algorithm (MQA), switching structures and mechanisms. This dissertation is dedicated to QoSNP in the S&M-platform.SUPANET can support different QoS according to users' application traffic. For time-critical traffic, the PVL (Permanent Virtual Line) service or SVL (Switched Virtual line) service can be used to meet the QoS requirements on per traffic basis. Shared PVL or SVL service can provided for less time-critical traffic, and the best effort service as in Internet can also be supported.QoSNP essentially plays two roles: one for establishment of a Switched Virtual Path (SVP) between a pair of edge SUPA-routers, and the other to make a QoS contract between a service user and the network service provider. Alternatively, it can be viewed as a QoS-constrained connection establishment protocol. An end-system can request for an SVP by calling up the QoSNP with required QoS parameters, the first node will forward the request to next node according to routing table if the low bound of QoS requirements can be met until all the nodes along the SVP can satisfy the requirements;otherwise, no SVP can be established. The significance of QoSNP is that it is the first step towards QoS control and QoS parameters agreed during negotiation will be used for QoS control and monitoring.QoS negotiation involves wide range of QoS parameters, especially those Quantifiable, such as throughput, transit delay, variation of transit delay (i.e. jitters), and data loss rate etc. QoS Protocol Data Units (PDU) have been defined for easy extension (e.g. for security class, robustness, etc.). Two negotiation modes have been designed to adapt to situations when only the requirement in one direction is known by the initiator or requirements in both directions are known. They are called TSDN (Twice Single-Direction Negotiation) and TDSN (Two-Direction Simultaneous Negotiation) respectively. Negotiation Time Sequence Diagrams and State transition Diagrams for both modes are provided in this dissertation and a simulation to TDSN has shown that it is operational.