Poor Man's Content Centric Networking (with TCP)

A number of different architectures have been proposed in support of data-oriented or information-centric networking. Besides a similar visions, they share the need for designing a new networking architecture. We present an incrementally deployable approach to content-centric networking based upon TCP. Content-aware senders cooperate with probabilistically operating routers for scalable content delivery (to unmodified clients), effectively supporting opportunistic caching for time-shifted access as well as de-facto synchronous multicast delivery. Our approach is application protocol-independent and provides support beyond HTTP caching or managed CDNs. We present our protocol design along with a Linux-based implementation and some initial feasibility checks

Duplicating RTP streams

Packet loss is undesirable for real-time multimedia sessions but can occur due to a variety of reasons including unplanned network outages. In unicast transmissions, recovering from such an outage can be difficult depending on the outage duration, due to the potentially large number of missing packets. In multicast transmissions, recovery is even more challenging as many receivers could be impacted by the outage. For this challenge, one solution that does not incur unbounded delay is to duplicate the packets and send them in separate redundant streams, provided that the underlying network satisfies certain requirements. This document explains how Real-time Transport Protocol (RTP) streams can be duplicated without breaking RTP or RTP Control Protocol (RTCP) rule

Options for Securing RTP Sessions

The Real-time Transport Protocol (RTP) is used in a large number of different application domains and environments. This heterogeneity implies that different security mechanisms are needed to provide services such as confidentiality, integrity, and source authentication of RTP and RTP Control Protocol (RTCP) packets suitable for the various environments. The range of solutions makes it difficult for RTP-based application developers to pick the most suitable mechanism. This document provides an overview of a number of security solutions for RTP and gives guidance for developers on how to choose the appropriate security mechanism

Packet loss characteristics of IPTV-like traffic on residential links

Packet loss is one of the principal threats to quality of experience for IPTV systems. However, the packet loss characteristics of the residential access networks which carry IPTV are not widely understood. We present packet level measurements of streaming IPTV-like traffic over four residential access links, and describe the extent and nature of packet loss we encountered. We discuss the likely impact of these losses for IPTV traffic, and outline steps which can ameliorate this

Wireless Video Transmission with Over-the-Air Packet Mixing

In this paper, we propose a system for wireless video transmission with a wireless physical layer (PHY) that supports cooperative forwarding of interfered/superimposed packets. Our system model considers multiple and independent unicast transmissions between network nodes while a number of them serve as relays of the interfered/superimposed signals. For this new PHY the average transmission rate that each node can achieve is estimated first. Next, we formulate a utility optimization framework for the video transmission problem and we show that it can be simplified due to the features of the new PHY. Simulation results reveal the system operating regions for which superimposing wireless packets is a better choice than a typical cooperative PHY.Comment: 2012 Packet Video Worksho

Crossroads, Connections, and Creativity: Musselman Library Strategic Plan

The Musselman Library Strategic Plan grew out of two all-staff meetings held in January 2007. During the first, library staff identified areas of strength and weakness, as well as opportunities for improvement and growth. Maureen Sullivan, an organization development consultant for libraries, led the next meeting. Ms. Sullivan helped to deepen the analysis begun during the previous meeting and encouraged the staff to begin envisioning the future of the Library. In late January, Robin Wagner, Director of Library Services, formed the Strategic Planning Committee (see list of participants below). The committee’s initial tasks were to complete an environmental scan and to identify upcoming trends and best practices in library services, while formulating mission and vision statements for Musselman Library. These were presented to the rest of the staff for feedback during meetings in March and April. Also in April, the Strategic Planning Committee invited other library staff to serve on task forces charged with creating goals and action items for the plan’s four core issues (see Appendix C). Maureen Sullivan facilitated the launching of these task forces, and each group, led by a member of the Strategic Planning Committee, then met independently numerous times during the next few weeks. The final task force reports were completed in early May and shared with the entire library staff. On May 21, Maureen Sullivan led an all-staff meeting to discuss the task force recommendations. Ms. Sullivan then met with the Strategic Planning Committee and Robin Wagner to begin the process of revising, prioritizing, and incorporating the goals and action items into one cohesive strategic plan. Crossroads, Connections, and Creativity: Musselman Library Strategic Plan was submitted to Robin Wagner, on June 12, 2007. [excerpt

BP’s use of posture to respond to the deepwater horizon crisis

This paper focuses on the posture the oil company BP adopted when faced with a legitimacy crisis during one of the worst environmental disasters in history. Against a backdrop of a discussion of the rhetorical aspects of image repair discourse and organisational legitimacy, Hearit’s strategy of corporate apologia was employed to determine the posture BP adopted in relation to the crisis. This paper adds to the literature on image repair strategies by heeding a call by Hearit for the context within which corporate apologia takes place to be taken account of, an approach that warrants a distinct line of research. The literature was further extended by complementing Hearit's strategy with semiotics and analysing its use in both the annual and sustainability reports. The additional focus on the sustainability reports is important, due to the high premium placed on sustainability in the changing business environment. On a practical level this paper contributes to an understanding of how organisations use sustainability reports to respond to legitimacy challenges

Resilient availability and bandwidth-aware multipath provisioning for media transfer over the internet (Best Paper Award)

Traditional routing in the Internet is best-effort. Path differentiation including multipath routing is a promising technique to be used for meeting QoS requirements of media intensive applications. Since different paths have different characteristics in terms of latency, availability and bandwidth, they offer flexibility in QoS and congestion control. Additionally protection techniques can be used to enhance the reliability of the network. This paper studies the problem of how to optimally find paths ensuring maximal bandwidth and resiliency of media transfer over the network. In particular, we propose two algorithms to reserve network paths with minimal new resources while increasing the availability of the paths and enabling congestion control. The first algorithm is based on Integer Linear Programming which minimizes the cost of the paths and the used resources. The second one is a heuristic-based algorithm which solves the scalability limitations of the ILP approach. The algorithms ensure resiliency against any single link failure in the network. The experimental results indicate that using the proposed schemes the connections availability improve significantly and a more balanced load is achieved in the network compared to the shortest path-based approaches