Search

D. Phoomikiattisak was funded by the Thai Government. B. Simpson was funded by Cisco Systems under a University Research Programme (URP) grant award. We discuss a key engineering challenge in implementing the Identifier- Locator Network Protocol (ILNP), as described in IRTF Experimental RFCs 6740-6748: enabling legacy applications that use the C sockets API. We have built the first two OS kernel implementations of ILNPv6 (ILNP as a superset of IPv6), in both the Linux OS kernel and the FreeBSD OS kernel. Our evaluation is in comparison with IPv6, in the context of a topical and challenging scenario: host mobility implemented as a purely end-to-end function. Our experiments show that ILNPv6 has excellent potential for deployment using existing IPv6 infrastructure, whilst offering the new properties and functionality of ILNP. Postprint

Through measurements on our testbed, we show how users of Netflix could make energy savings of up to 34% by adjusting video quality settings. We estimate the impacts of these quality settings on the energy consumption of client systems and the network. If users exercise choice in their video streaming habits, over 100 GWh of energy a year could be saved on a global scale. We discuss how providing energy usage information to users of digital video could enable them to make choices of video settings to reduce energy usage, and we estimate savings on associated electricity costs and carbon emissions. Postprint

Video is the most prevalent traffic type on the Internet today. Significant research has been done on measuring user's Quality of Experience (QoE) through different metrics. We take the position that energy use must be incorporated into quality metrics for digital video. We present our novel, energy-aware QoE metric for video, the Energy-Video Index (EnVI). We present our EnVI measurements from the playback of a diverse set of online videos. We observe that 4K-UHD (2160p) video can use ~30% more energy on a client device compared to HD (720p), and up to ~600% more network bandwidth than FHD (1080p), without significant improvement in objective QoE measurements.

Internet users seek solutions for mobility, multi-homing, support for localised address management (i.e. via NATs), and end-to-end security. Existing mobility approaches are not well integrated into the rest of the Internet architecture, instead primarily being separate extensions that at present are not widely deployed. Because the current approaches to these issues were developed separately, such approaches often are not harmonious when used together. Meanwhile, the Internet has a number of namespaces, for example the IP address or the Domain Name. In recent years, some have postulated that the Internet's namespaces are not sufficiently rich and that the current concept of an address is too limiting. One proposal, the concept of separating an address into an Identifier and a separate Locator, has been controversial in the Internet community for years. It has been considered within the IETF and IRTF several times, but always was rejected as unworkable. This paper takes the position that evolving the naming in the Internet by splitting the address into separate Identifier and Locator names can provide an elegant integrated solution to the key issues listed above, without changing the core routing architecture, while offering incremental deployability through backwards compatibility with IPv6.

Through measurements on our testbed, we show how users of Netflix could make energy savings of up to 34% by adjusting video quality settings. By using Netflix as a case study, we aim to assess the impact of energy usage in Video-on-demand (VoD) services. We estimate the potential impact of video quality settings on energy usage on a global scale.

Allowing digital video users to make choices of picture size and codec would significantly reduce energy usage, electricity costs and the carbon footprint of Internet users. Our empirical investigation shows a difference of up to a factor of 3 in energy usage for video decoding using different codecs at the same picture size and bitrate, on a desktop client system. With video traffic already responsible for the largest and fastest growing proportion of traffic on the Internet, a significant amount of energy, money and carbon output is due to video. We present a simple methodology and metrics that can be used to give an intuitive, quantitative and comparable assessment of the energy usage of video decoding. Providing energy usage information to users would empower them to make sensible choices. We demonstrate how small energy savings for individual client systems could give significant energy savings when considered at a global scale.

This work was partly supported by the IU-AC project, funded by grant EP/J016756/1 from the Engineering and Physical Sciences Research Council (EPSRC). We show that students in a school lab environment will change their behaviour to be more energy efficient, when appropriate incentives are in place, and when measurement-based, real-time feedback about their energy usage is provided. Rewards incentivise `non-green' users to be `green' as well as encouraging those users who already claim to be `green'. Measurement-based feedback improves user energy awareness and helps users to explore and adjust their use of computers to become `greener', but is not sufficient by itself. In our measurements, weekly mean group energy use as a whole reduced by up to 16%; and weekly individual user energy consumption reduced by up to 56% during active use. The findings are drawn from our longitudinal study that involved 83 Computer Science students; lasted 48 weeks across 2 academic years; monitored a total of 26778 hours of active computer use; collected approximately 2TB of raw data. Publisher PDF

Network congestion is a fundamental problem facing Internet users today. A network where users are selfish, and thus reluctant to defer to other users, may result in the famous "tragedy of the commons", where, in the absence of controls, a shared resource is overconsumed by individuals who consider only their personal costs and not the cost to society as a whole. In terms of the Internet, the "tragedy" could be viewed as congestive collapse, resulting from overconsumption of the shared network resource. It is important to distinguish congestion pricing from other forms of network pricing. Charging network users for the congestion they cause can lead to more efficient network utilization by forcing them to take social costs into account. In a congestion-pricing framework, the congestion charge would replace usage and QoS charges. Users would pay their ISPs a subscription charge to cover fixed costs and a congestion charge only when appropriate. This pricing scheme is feasible because, in the absence of congestion, the marginal cost of a network link is practically zero. Congestion pricing can also benefit network operators. By indicating the level of congestion and the user tolerance of it in their networks, congestion pricing can inform operators about when to re-provision and increase network capacity.

In the last few years there has been considerable research toward extending the Internet architecture to provide quality of service guarantees for the emerging real-time multimedia applications. QoS provision is a rather controversial endeavour. At one end of the spectrum there were proposals for reservations and per-flow state in the routers. These models did not flourish due to the network's heterogeneity the complexity of the mechanisms involved, and scalability problems. At the other end, proposals advocating that an overprovisioned best effort network will solve all the problems are not quite convincing either. The authors believe that more control is clearly needed for protecting best effort service. An important requirement is to prevent congestion collapse, keep congestion levels low, and guarantee fairness. Appropriate control structures in a best effort service network could even be used for introducing differentiation. This could be achieved without sacrificing the best effort nature of the Internet or stressing its architecture beyond its limits and original design principles. We revisit the best effort service model and the problem of congestion while focusing on the importance of cooperative resource sharing to the Internet's success, and review the congestion control principles and mechanisms which facilitate Internet resource sharing.

The CATV network operators hope to offer digital services and evolve their networks to full service networks. There are many hurdles for them at the moment in the transition to a digital network and digital service offering from the current analog-based technology. Key to the success of the transition will be a well-integrated and capable management system to allow CATV operators and service providers to control the network as well as the services they will offer. The CATV operators need to agree on a common data communication infrastructure and plan how their new digital services will be offered to subscribers without disrupting the current customer base of analog service users. The choice of network technology and data communication protocols will have a strong influence on the network management technology chosen. A vital element for the provision of a common open communication architecture as well as for the purposes of network management is that the IP is used. The adoption of existing standards is vital in order to establish a fast route to open network management for CATV networks. It is possible that CATV operators and service providers will have to integrate existing SNMP management systems and TMN/OSI management, with newer integrated service management systems based on TINA and implemented on a CORBA platform. There is a strong need to address security issues before any of these technologies can be deployed for service. There is currently investment (deployed systems and research) which uses each of the technologies mentioned, so these technologies will need to coexist. This article highlights the differences between the North American and European network architectures, and outlines the European network and network management scenario. This is based on the authors involvement in a Pan-European CATV project, Integrated Broadband Communication over Broadcast Networks-IBCoBN.

This paper describes the design and implementation of a secure management protocol for the management of distributed applications. The protocol is a modified use of the ISO CMIP protocol, with additional mechanisms and behavior to provide the following security services:Mutual authentication of communicating parties. Both parties can prove to each other that they are who they claim to be by the exchange of signed credentials.Stream integrity for management information packets (protocol data units—PDUs). The management information exchanged between the parties is protected from replay, misordering, modification, insertion, and deletion of the PDUs.Confidentiality of the management PDUs. Only the communicating parties can read the information passed between them. The mechanism used also provides a level ofback traffic protection andperfect forward secrecy. In previous work we have implemented apublic-key based system. Here, we present an experiment based on the use of asecret-key mechanism, for a faster,lightweight approach. The authentication mechanism makes use of the MD5 algorithm and the DES encryption standard. The PDU integrity mechanisms make use of a pseudo random number sequence for PDU numbering and the MD5 algorithm for generating unforgeable signatures for the PDUs.

Global Information Grid (GIG) operations would benefit greatly from improved support for virtual machines (VMs) that can migrate not only between physical devices within a datacentre, but also between physical devices located on different continents, while maintaining their existing IP communications sessions. Such VM migration can enable improvements with: CPU load-balancing, network traffic-engineering, distributed denial of service (DDoS) mitigation, fault-tolerance, and resilience. Existing migration approaches often require complex network configuration and management, may often require use of expensive proprietary technologies, and also often require active cooperation from upstream service providers. We describe a VM mobility approach that enables datacentre operators to directly and unilaterally provide and control intra-site and wide-area VM mobility. We present several use cases with different degrees of location transparency. Our mechanism is based on a new naming approach which has been recommended for progression within the IETF.

We present vNurse, a system based on a smartphone platform that permits comprehensive, secure and modular patient remote monitoring outside a clinical environment, e.g. in the home. Using both virtualisation of the phone OS and virtual mobile networks of sensors with full Internet Protocol (IP) connectivity, we enable real-time remote sensor readings of patient Wireless Body Area Networks (WBANs) to be stored, processed and forwarded securely to healthcare practitioners based at clinical sites, while patients are remote or mobile.

One of the operational goals of a middleware platform is to provide a mechanism of distributing computation requests in a way that hides from the programmer the complexity of the underlying systems platform. This means that distribution mechanisms used to harness a set of computer and network resources should not expose to the programmer the detailed systems aspects which are unrelated to their application. Ideally, the programmer should be left to concentrate on the functionality of his/her application without having to be concerned with how the distribution is achieved or how the resources are used. However, this is not true today: programmers need to be aware of details of the middleware in use and are constrained by it in the design of their application, e.g. API constraints. We present a proof-of-concept demonstration of a middleware platform that imposes absolutely no constraints on the programmer apart form those used in the programming language itself. We demonstrate the efficacy of our approach with a prototype implementation in Java, running on a cluster of 20 nodes with a performance comparison with XML-RPC and Java-RMI.

One of the aims of cloud-based services is to offer cost savings through elastic service provision. This elasticity refers to use of resources by the customer and the provision of resources by the provider. An increasingly important resource to consider is energy (or power). As cloud services are intended to be ‘always on’ the energy costs of cloud service provision is already significant, and will continue to rise as global energy prices continue to rise and more users make use of cloud services. While providers can invest in energy-efficient hardware, how can we make users (customers) energy-aware, and incentives users towards energy-efficient use of cloud systems? Clearly, being able to measure actual energy usage will allow the provision of suitable feedback to users, as well as enable new energy-aware systems metrics that allow systems management policies to become responsive to energy usage. We list the requirements and described a prototype for such an energy measurement system.

This chapter offers a survey of the emerging field of private peer-to-peer networks, which can be defined as internet overlays in which the resources and infrastructure are provided by the users, and which new users may only join by personal invitation. The last few years have seen rapid developments in this field. We describe deployed systems, classify them architecturally, and identify some technical and social tradeoffs in the design of private peer-to-peer networks.

This paper describes two approaches to manipulating JPEG2000 frames with programmable and active networks. The first approach is the use of transcoding and the second is intelligent dropping. These two approaches where considered, in particular, for possible deployment with space based platforms; specifically, communication satellites which are not only IP enabled but may host active components. Each approach offers different possibilities and may be suitable for solving overlapping but different problems.

Military communications currently require secure end-to-end, resilient connectivity via multi-homed connections, and need to support both mobile hosts and mobile networks. Today, such functions are possible to some degree, but the functions are not harmonised. Standards that support these functions were designed independently and implemented in isolation. So, achieving converged capabilities for optimal communications in forward operating areas is a technical challenge, and results in a complex network landscape which is likely to be difficult to operate and manage, and brittle under failure conditions. From our ongoing work, we present a new naming approach and use this to formulate a proposal to provide the following capability harmoniously: (a) multi-homed connectivity for traffic engineering and resilience; (b) true end-to-end network-layer security with high compatibility with the HAIPE architecture; (c) support for mobile hosts and mobile networks. Our approach is backwards compatible with IPv6 network equipment (existing IPv6 backbones can be used), and is also incrementally deployable.

Internet users seek solutions for mobility, multi-homing, support for localised address management (i.e. via NATs), and end-to-end security. Existing mobility approaches are not well integrated into the rest of the Internet architecture, instead primarily being separate extensions that at present are not widely deployed. Because the current approaches to these issues were developed separately, such approaches often are not harmonious when used together. Meanwhile, the Internet has a number of namespaces, for example the IP address or the Domain Name. In recent years, some have postulated that the Internet's namespaces are not sufficiently rich and that the current concept of an address is too limiting. One proposal, the concept of separating an address into an Identifier and a separate Locator, has been controversial in the Internet community for years. It has been considered within the IETF and IRTF several times, but always was rejected as unworkable. This paper takes the position that evolving the naming in the Internet by splitting the address into separate Identifier and Locator names can provide an elegant integrated solution to the key issues listed above, without changing the core routing architecture, while offering incremental deployability through backwards compatibility with IPv6.

We describe a method for enabling dependable forwarding of messages in untrusted networks. Nodes perform only relatively lightweight operations per message, and only the originator and destination need to trust each other. Whereas existing protocols for dependable communication rely on establishing a verifiable identity for every node, our protocol can operate in networks with unknown or varying membership and with no limits on the creation of new identities. Our protocol supports the maintenance of unlinkability: relays cannot tell whether a given originator and destination are communicating. The destination of each message generates an unforgeable acknowledgement (U-ACK) that allows relays and the originator to verify that the message was delivered unmodified to the destination, but relays do not need to share keys with the originator or destination, or to know their identities. Similarly, the endpoints do not need to know the identities of the relays. U-ACKs can be seen as a building block for dependable communication systems; they enable nodes to measure the level of service provided by their neighbours and optionally to adjust the level of service they provide in return, creating an incentive for nodes to forward messages. Our work is ongoing.

This paper presents the design of a scalable decentralized signaling underlay infrastructure, which features a DHT based management information storage and query-based state lookup mechanism. The signaling underlay is aimed to apply a decentralized "peer-to-peer" style searching and discovering engine into the management and control plane of the overlay network, including grid networks and p2p applications, to facilitate deployment of QoS service.

Recently, grid and peer-to-peer overlays have attracted attention from research communities as well as industry. However, the overwhelming majority of industrial, commercial and academic activities are geared around applications, servers, and middleware. There have been some efforts in the management of the underlying networks (the connectivity for the overlays), but far from enough. This paper proposes a resilient, fault-adaptive, overlay resource management framework, with lightweight state management infrastructure, taken from some ongoing work by the authors in this area. This research aims to solve the problems of: (a) managing distributed network resources in a decentralized way; (b) providing resilient QoS for highly dynamic networks.

Research into providing different levels of network Quality of Service (QoS) often assumes that there is a large market for QoS-sensitive applications that will be fulfilled once QoS-enabled networks have been deployed. Multiplayer networked games are an example of such an application that requires QoS, and hence will only become popular if QoS is made widely available. The prima facie evidence, however, is that games are already popular, in spite of the existing QoS-free best-effort Internet.Networked games may have become popular despite the lack of QoS because players "make do" with what is available to them. Such popularity is a double-edged sword. It may mean that there is a demand, as yet unfulfilled, from game players for QoS-enabled networks. On the other hand, it may mean that players have become accustomed to playing games without QoS, and therefore might be less willing to pay for higher QoS when it does eventually become available.In this paper we present the results of a short experiment to examine the QoS tolerances of game players. We use a set of popular First Person Shooter (FPS) game servers that are publicly available to Internet users at large. By systematically altering the network latency to the servers, we attempt to study whether degraded QoS (in the form of higher network delay) affects a user's decision to participate in the game.We find that increased network delay has an effect on a user's decision to join a game server. It appears, however, that there is no significant difference in the number of players who leave the game as a result of increased delay. We speculate that this may be due to a user's enjoyment exceeding their QoS-sensitivity, and discuss the implications of our findings with respect to providing and charging for QoS.

A major aspect of Open Systems’ network management is the inter-working between distinct Management architectures. This paper details the development of a generic object oriented application level gateway that achieves seamless coexistence between OSI and SNMPv1 management systems. The work builds upon the Network Management Forum’s `ISO/CCITT and Internet Management Coexistence’ activities. The power of the OSI Systems Management Functions is made available for the management of SNMPvl based resources, bringing fully event driven management to the SNMP domain.

Much of the network management technology today still centres around a remote monitoring approach. One would like to have a more intrusive management capability but in a large distributed system one must have confidence that management activities can not be subverted, whether by accident or by malicious intent. To achieve this goal, one requires the management applications to have security mechanisms that will prevent unprivileged users from altering the system accidentally but also, more importantly, to prevent possible attacks from a third party who may disrupt or misuse services. This paper describes some services and mechanisms with which the authors have experimented to allow secure remote management of a distributed system in a real service environment. Although there are many standards documents describing various security mechanisms, some aspects of these documents are not stable and in other cases we can not apply the mechanisms they describe due to restrictions in our development and deployment environment. In such cases we have had to make some adaptations.

The Coalition Peering Domain (CPD) is a recent innovation within the field of mesh networking. It facilitates the management of community-area networks in a distributed and scalable form, allowing devices to pool their network resources (particularly egress links) to the common good. However, as in P2P systems, this form of cooperative sharing architecture raises significant concerns about the effect of free-riders: nodes that utilise the bandwidth of others without providing an adequate return to the community. To address this problem, we propose STRUDEL, a distributed framework that tackles the problem of free-riders and consists of: (i) a mechanism for the detection of malicious peers; (ii) a formal Bayesian trust model, to assess peers' trustworthiness; (iii) a forwarding mechanism based on the maximisation of trust-informed utility.

In the near future, billing for network services will not only be concerned with time or volume based accounting but also in ways of measuring the quality of the service provided. Dynamic price schemes, such as congestion-based charging, have been proposed. In some of these models, the charging infrastructure relies on the distribution of electronic tariffs to end-users machines. The tariff structure includes the price information and an algorithm to calculate the charge. Thus, the monitoring of network usage according to this tariff is essential within these frameworks. However, little attention has been given to the security issues associated with Internet metering in these schemes. This has had a great impact on the new models proposed today, since security has become a major concern in open networks. Systems that naturally have incentive to fraud, such as metering systems used for billing purposes, must deal with security threats in large scale environments. The article compiles the security issues of a dynamic networked system where electronic tariffs and service level agreement (SLA) structures are distributed among service providers and customers. To address these issues, a set of security protocols is outlined.