593 research outputs found

    Two issues in reservation establishment

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    This paper addresses two issues related to resource reservation establishment in packet switched networks o ering realtime services. The rst issue arises out of the natural tension between the local nature of reservations (i.e., they control the service provided on a particular link) and the end-to-end nature of application service requirements. How do reservation establishment protocols enable applications to receive their desired end-to-end service? We review the current onepass and two-pass approaches, and then propose a new hybrid approach called one-pass-with-advertising. The second issue in reservation establishment weconsider arises from the inevitable heterogeneity in network router capabilities. Some routers and subnets in the Internet will support realtime services and others, such as ethernets, will not. How can a reservation establishment mechanism enable applications to achieve the end-to-end service they desire in the face of this heterogeneity? We propose an approach involving replacement services and advertising to build end-to-end service out of heterogeneous per-link service o erings.

    Flexibility as an Instrument in Digital Rights Management

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    We consider the optimal design of flexible use in a digital-rights-management policy. The basic model considers a single distributor of digital goods and a continuum of consumers. Each consumer can acquire the digital good either as a licensed product or an unlicensed copy. The availability of (or access to) unlicensed copies is increasing both in the number of licensed copies and in the flexibility accorded to licensed copies. We thus analyze the optimal design of flexibility in the presence of unlicensed distribution channels (the "greynet"). We augment the basic model by introducing a “secure platform” that is required to use the digital good. We compare the optimal design of flexibility in the presence of a platform to the one without a platform. Finally, we analyze the equilibrium provision when platform and content are complimentary goods but are distributed and priced by different sellers.Digital Rights Management, Platform, Flexibility, Piracy

    Pricing under the Threat of Piracy: Flexibility and Platforms for Digital Goods

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    We consider the optimal design of flexible use in a digital-rights-management policy for a digital good subject to piracy. Consumers can acquire the digital good either as a licensed product or as an unlicensed copy. The ease of access to unlicensed copies is increasing in the flexibility accorded to licensed copies. The content provider has to trade off consumers' valuation of a licensed copy against the sales lost to piracy. We enrich the basic model by introducing a "secure platform" that is required to use the digital good. We show that the platform allows for the socially optimal provision of flexibility for the digital good but only if both are sold by an integrated firm.Digital goods, Digital rights management, Platform, Flexibility, Piracy

    Supporting Real-Time Applications in an Integrated Services Packet Network: Architecture and Mechanism

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    This paper considers the support of real-time applications in an Integrated Services Packet Network (ISPN). We first review the characteristics of real-time applications. We observe that, contrary to the popular view that real-time applications necessarily require a fixed delay bound, some real-time applications are more flexible and can adapt to current network conditions. We then propose an ISPN architecture that supports two distinct kinds of real-time service: guaranteed service, which is the traditional form of real-time service discussed in most of the literature and involves pre-computed worst-case delay bounds, and predicted service, which uses the measured performance of the network in computing delay bounds. We then propose a packet scheduling mechanism that can support both of these real-time services as well as accommodate datagram traffic. We also discuss two other aspects of an overall ISPN architecture: the service interface and the admission control criteria.Research at MIT was supported by DARPA through NASA Grant NAG 2-582, by NSF grant NCR-8814187, and by DARPA and NSF through Cooperative Agreement NCR-8919038 with the Corporation for National Research Initiatives

    Recursive SDN for Carrier Networks

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    Control planes for global carrier networks should be programmable (so that new functionality can be easily introduced) and scalable (so they can handle the numerical scale and geographic scope of these networks). Neither traditional control planes nor new SDN-based control planes meet both of these goals. In this paper, we propose a framework for recursive routing computations that combines the best of SDN (programmability) and traditional networks (scalability through hierarchy) to achieve these two desired properties. Through simulation on graphs of up to 10,000 nodes, we evaluate our design's ability to support a variety of routing and traffic engineering solutions, while incorporating a fast failure recovery mechanism