Design and initial validation of the Raster method for telecom service availability risk assessment

Crisis organisations depend on telecommunication services; unavailability of these services reduces the effectiveness of crisis response. Crisis organisations should therefore be aware of availability risks, and need a suitable risk assessment method. Such a method needs to be aware of the exceptional circumstances in which crisis organisations operate, and of the commercial structure of modern telecom services. We found that existing risk assessment methods are unsuitable for this problem domain. Hence, crisis organisations do not perform any risk assessment, trust their supplier, or rely on service level agreements, which are not meaningful during crisis situations. We have therefore developed a new risk assessment method, which we call RASTER. We have tested RASTER using a case study at the crisis organisation of a government agency, and improved the method based on the analysis of case results. Our initial validation suggests that the method can yield practical results

Characterizing and Improving the Reliability of Broadband Internet Access

In this paper, we empirically demonstrate the growing importance of reliability by measuring its effect on user behavior. We present an approach for broadband reliability characterization using data collected by many emerging national initiatives to study broadband and apply it to the data gathered by the Federal Communications Commission's Measuring Broadband America project. Motivated by our findings, we present the design, implementation, and evaluation of a practical approach for improving the reliability of broadband Internet access with multihoming.Comment: 15 pages, 14 figures, 6 table

Link failure testing project on a satellite SDN network using Bidirectional Forwarding Detection

This project focuses on implementing a variable grid topology network for simulating an inter-satellite links connection to evaluate link failure detection times in a satellite SoftwareDefined Networking (SDN) using the Bidirectional Forwarding Detection (BFD) protocol (RFC 5880). Today, there is significant growth and deployment of LEO satellite networks, and SDN technology is being successfully used in these LEO satellite constellation networks due to the flexibility that this technology offers in the face of dynamic variation in topology network, limited bandwidth and traffic variations. An important point for the correct operation of these networks is the reliability and stability of the links that interconnect the satellites of the constellation, since this constellation is in permanent motion, orbiting the earth. The work developed in this project is directly related to this topic and the BFD detection protocol has been used to determine the connectivity failures of the test network links. The BFD is a protocol which provides fast forwarding path failure detection times and it is independent from physical media, routing protocols and data protocols. The BFD protocol works in the forwarding plane and is well suited for use with SDN switches. The testbed has been built using the "ContainerNet" Python API to implement the network topology and link interconnection of each satellite node. The satellite switching service is implemented in a docker instance, using OpenVirtualSwitch (OVS) as the internal packet switch of each node. OpenVirtualSwitch is an SDN-compliant programmable switching network device that has support for the BFD protocol. A transmission scenario is built on this switching network. This scenario includes two nodes that work as communication endpoints. The nodes have been configured so that between the endpoints there are two separate alternative paths. In addition to the datapath configuration, the BFD protocol has been configured to monitor the status of each link. A software developed running in all intermediate nodes are able to notify a link failure upstream of the datapath until the end nodes. An then end nodes can switch to another path. The final results must determine which are the BFD parameters to achieve a compromise between the BFD packet signaling period and the bandwidth used to keep the VoIP communication parameters within the acceptable limits in the event of a link failure with a route update

Network neutrality: Hong Kong's perspectives

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Quality in Measurement: Beyond the deployment barrier

Network measurement stands at an intersection in the development of the science. We explore possible futures for the area and propose some guidelines for the development of stronger measurement techniques. The paper concludes with a discussion of the work of the NLANR and WAND network measurement groups including the NLANR Network Analysis Infrastructure, AMP, PMA, analysis of Voice over IP traffic and separation of HTTP delays into queuing delay, network latency and server delay