| 1. |
- Carlsson, Niklas, et al.
(author)
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Optimized Dynamic Cache Instantiation
- 2020
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In: 2020 IFIP NETWORKING CONFERENCE AND WORKSHOPS (NETWORKING). - : IEEE. - 9783903176287 ; , s. 145-153
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Conference paper (peer-reviewed)abstract
- By caching content at geographically distributed servers, content delivery applications can achieve scalability and reduce wide-area network traffic. However, each deployed cache has an associated cost. As the request rate from a region varies (e.g., according to a daily cycle), there may be periods when the request rate is high enough to justify this cost, and other periods when it is not. Cloud computing offers a solution to problems of this kind, by supporting the dynamic allocation and release of resources. In this paper, we analyze the potential benefits from dynamically instantiating caches using resources from cloud service providers. We develop novel analytic caching models that accommodate time-varying request rates, transient behavior as a cache fills following instantiation, and selective cache insertion policies. Using these models, within the context of a simple cost model, we then develop bounds and compare policies with optimized parameter selections to obtain insights into key cost/performance tradeoffs. We find that dynamic cache instantiation can provide substantial cost reductions, that potential reductions strongly dependent on the object popularity skew, and that selective cache insertion can be even more beneficial in this context than with conventional edge caches.
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| 2. |
- da Costa, Luis Antonio L. F., et al.
(author)
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Poster: SafeSmart - A VANET system for efficient communication for emergency vehicles
- 2020
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In: IFIP Networking 2020 Conference and Workshops June 22-25, 2020 - Paris, France. - Piscataway : Institute of Electrical and Electronics Engineers (IEEE). - 9783903176287 - 9781728167107 ; , s. 643-645
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Conference paper (peer-reviewed)abstract
- One important use case for Vehicular Ad-hoc Networks (VANETs) are applications related to emergency vehicles (EV). V2I (Vehicle-to-Infrastructure) communication can provide the infrastructure and protocol stack necessary to establish a communication channel between the transceivers in the EVs and the ones in the traffic lights, reducing accident risks and also help save valuable time. This paper outlines the system design of an EV warning system that makes use of V2I communication. A prototype of the system has been tested in a traffic simulation environment including EVs and traffic lights. To evaluate the system we performed a simulation and conducted a performance comparison between the travel times for EVs in normal traffic and when the system is in use. © 2020 IFIP.
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| 3. |
- Korzhitskii, Nikita, et al.
(author)
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Characterizing the Root Landscape of Certificate Transparency Logs
- 2020
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In: Proceedings of the 19th International IFIP TC6 Networking Conference, IFIP Networking 2020, Paris, France, June 22-25. - : IEEE. - 9783903176287 - 9781728167107 ; , s. 190-198
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Conference paper (peer-reviewed)abstract
- Internet security and privacy stand on the trustworthiness of public certificates signed by Certificate Authorities (CAs). However, software products do not trust the same CAs and therefore maintain different root stores, each typically containing hundreds of trusted roots capable of issuing “trusted” certificates for any domain. Incidents with misissued certificates motivated Google to implement and enforce Certificate Transparency (CT). CT logs archive certificates in a public, auditable and append-only manner. The adoption of CT changed the trust landscape. As a part of this change, CT logs started to maintain their own root lists and log certificates that chain back to one of the trusted roots. In this paper, we present a first characterization of this emerging CT root store landscape, as well as the tool that we developed for data collection, visualization, and analysis of the root stores. As part of our characterization, we compare the logs’ root stores and quantify their changes with respect to both each other and the root stores of major software vendors, look at evolving vendor CT policies, and show that root store mismanagement may be linked to log misbehavior. Finally, we present and discuss the results of a survey that we have sent to the log operators participating in Apple’s and Google’s CT log programs.
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| 4. |
- Persson Proos, Daniel, et al.
(author)
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Performance Comparison of Messaging Protocols and Serialization Formats for Digital Twins in IoV
- 2020
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In: 2020 IFIP NETWORKING CONFERENCE AND WORKSHOPS (NETWORKING). - : IEEE. - 9783903176287 ; , s. 10-18
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Conference paper (peer-reviewed)abstract
- This paper compares the performance tradeoffs of popular application-layer messaging protocols and binary serialization formats in the context of vehicle-to-cloud communication for maintaining digital twins. Of particular interest are solutions that enables emerging delay-sensitive Intelligent Transport System (ITS) features, while reducing data usage in mobile networks. The evaluated protocols are Constrained Application Protocol (CoAP), Advanced Message Queuing Protocol (AMQP), and Message Queuing Telemetry Transport (MQTT), and the serialization formats studied are Protobuf and Flatbuffers. The results show that CoAP - the only User Datagram Protocol (UDP) based protocol evaluated - has the lowest latency and overhead, but is not able to guarantee reliable transfer, even when using its confirmable message feature. For our context, the best performer that guarantees reliable transfer is MQTT. For the serialization formats, Protobuf is shown to have faster serialization speed and three times smaller serialized message size than Flatbuffers. In contrast, Flatbuffers uses less memory and has shorter deserialization time, making it an interesting alternative for applications where the vehicle is the receiver of time sensitive information. Finally, insights and implications on ITS communication are discussed.
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