In this paper, the problem of connection provisioning with QoS guarantees is studied in DiffServ/MPLS over optical networks. In most previous studies, the objective is to provide bandwidth guaranteed LSPs, without considering service differentiation. In practice, to guarantee QoS for some class of services in a DiffServ scenario, other constraints besides bandwidth should be enforced on the LSP and the network. We discuss these constraints and take them into account in the routing procedure. The simulation results show that QoS is guaranteed at the cost of higher bandwidth blocking probability, and an appropriate preemption mechanism is indispensable in the DiffServ/MPLS over optical networks.
This paper proposes a collision-free access protocol based on scalable slotted ring network architecture. Multiple QoS classes are supported directly in optical layer. The Qos scheme adopts the fixed home slots strategies to satisfy the requirements of services. Furthermore, efficient slot reuse is proposed. Simulation results show that the protocol can achieve good performance to guarantee the quality of traffic.
This paper addresses QoS provisioning mechanisms in the WDM optical networks. With the appearance of metropolitan optical network, a hierarchical metro and wide area optical network will be envisioned in the near future. This hierarchical optical transport network is often divided into optical domains by geography, administration and technology, which usually employ different QoS routing algorithms and policies. To provide end-to-end optical QoS is becoming a new challenge for the optical network design. In this paper, we first give an overview of issues on the QoS provisioning in data, control and management planes of the WDM optical network. And then three provisioning approaches are analyzed and compared. Finally, we propose an agent-based hybrid centralized/distributed QoS provisioning mechanism based on the concept of domain agent. This agent-based hybrid mechanism employs centralized approach in the domain and distributed approach between domains. It offers scalability and intra-domain optimal QoS routing. It also keeps independence and interoperability between domains.
Since optical ring is the main topology in metro ring, it is essential to study on the medium access control protocol. In this paper, medium access control protocols in metro optical ring are discussed. We firstly classify the current protocols, then analyze performance requirements and technology attributes thoroughly. At last, several topics remained to be studied are presented.
The need to provide QoS-guaranteed services in the WDM optical networks is becoming increasingly important because of a variety of candidate client networks (e.g., IP, ATM, SONET/SDH) and the requirement for QoS-delivery within the transport layers. This article addresses the QoS problem and presents a framework of QoS provisioning in the WDM optical network. We first characterize the QoS problem in the WDM optical network by comparing with that in the traditional networks. Then we propose a QoS service model in the optical domain called extended differentiated optical services (E-DoS) model based on a set of optical parameters that captures the quality, the reliability and the priority of an optical connection. Each component of the E-DoS model has been analyzed in detail in this article.
QoS guarantees need to be constant along the entire path between source and destination, i.e. end-to-end. However, for traffics across several domains, the domains are often with different administrations and technical characteristics. To guarantee QoS in the inter-domains is becoming a challenge for end-to-end QoS. Especially, for DiffServ flows traversing a transit WDM network in the Optical Internet, there exits a QoS gap between the DiffServ-aware MPLS sub-network and the MPλS sub-network. In this article, we study the convergence of the QoS schemes in these two sub-networks to achieve end-to-end QoS in the Optical Internet. We first give a review of QoS models in the IP network and WDM optical network and compare their difference for supporting QoS. Then, we study the end-to-end QoS mechanism in the Optical Internet, and propose a QoS mapping method between the IP/MPLS sub-network and the MPλS sub-network. Based on the QoS mapping method, an end-to-end QoS guaranteed LSP provisioning scheme in the Optical Internet is presented at this end of the paper.
Internet backbone network is undergoing a large-scale transformation from the current complex, static and multi-layer electronic-based architecture to the emerging simplified, dynamic and single-layer photonic-based architecture. The explosive growth in the Internet, multi-media services, and IP router links are demanding the next generation Internet that can accommodate the entire traffic in a cost-effective manner. There is a consensus in current industries that IP over WDM integration technologies will be viable for the next generation of the optical Internet where the simplified flat network architecture can facilitate the networking performance and the networking management. In this paper, we firstly propose a novel node architecture-Terabit Optical Router (TOR) for building the next generation optical Internet and analyzes each key function unit of TOR including multi-granularity electrical-optical hybrid switching fabrics, unified control plane unit and so on. Secondly, we discussed the unified control plane unit of TOR in detailed Thirdly we describe our cost vs. performance analysis for various application of TOR. According to our evaluation carriers can get a cost reduction of more than 60 percent by using the TOR. Finally, we reach conclusions that TORs rather than OBS or BFR(Big Fat Router) routers, a cost effective multi-granularity switching and routing technique, are feasible to build the next generation Internet.
Internet backbone network is undergoing a large-scale transformation from the current complex, static and multi-layer electronic-based architecture to the emerging simplified, and dynamic and one-layer photonic-based architecture. The explosive growth in the Internet, multi-media services, and IP router links are demanding the next generation Internet that can accommodate the entire traffic in a cost-effective manner. There is a consensus in current industries that IP over WDM integration technologies will be viable for the next generation of the optical Internet where the simplified flat network architecture can facilitate the networking performance and the networking management. In this paper, we firstly propose a novel node architecture-Terabit Optical Router (TOR) for building the next generation optical Internet and analyses each key function unit of TOR including multi-granularity electrical-optical hybrid switching fabrics, unified control plane unit and so on. Secondly, we give the unified routing definition of multi-layer in TOR and present control plane software structure with emphasis on multi-layer routing issues. Thirdly we describe our cost vs. performance analysis for various application of TOR. According to our calculation, we can get a cost reduction of more than 60 percent by using the TOR. Finally, we reach conclusions that TORs rather than OBS/OPS-based optical routers or big fat router, a cost effective multi-granularity switching and routing technique, are feasible to build the next generation Internet in the coming 5-10 years.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.