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We have conducted an empirical study of the latest 5GHz IEEE 802.11wireless LAN (WLAN) variants of 802.11n (5GHz) and 802.11ac (Wave 1), underdifferent cell load conditions. We have considered typicalconfigurations of both protocols on a Linux testbed. Under light load, there is no clear difference between 802.11n and 802.11ac in terms ofperformance and energy consumption. However, in some cases of highcell load, we have found that there may be a small advantage with802.11ac. Overall, we conclude that there may be little benefit inupgrading from 802.11n (5GHz) to 802.11ac in its current offering, as thebenefits may be too small.

We provide an empirical evaluation of an IEEE 802.11ac Wireless Local Area Network (WLAN) cell with Multiple User Multiple Input Multiple Output (MU-MIMO) technology. We conducted our experiments on a testbed comprising consumer equipment under different office scenarios using 40MHz and 80MHz channels. This is the first performance study of MU-MIMO with 802.11ac in an operational scenario using a commercial access point. We find that, for clients that do not support MU-MIMO, operating in a cell that has MU-MIMO enabled may result in reduced performance.

Kimberly E Price, Najma Saleem, Georgina Lee, Michael SteinbergMassachusetts College of Pharmacy and Health Sciences University, Worcester, MA, USAAbstract: Development of BCR-ABL tyrosine kinase inhibitors (TKIs) have improved outcomes for patients diagnosed with chronic myeloid leukemia and Philadelphia chromosome positive acute lymphoblastic leukemia. However, resistance or intolerance to these TKIs still leaves some patients without many treatment options. One point mutation in particular, the T315I mutation, has been shown to be resistant to first and second generation TKIs. The third generation TKI, ponatinib, may provide an option for these patients. Ponatinib (Iclusig®), an orally available, pan-tyrosine kinase inhibitor has a unique binding mechanism allowing inhibition of BCR-ABL kinases, including those with the T315I point mutation. A Phase II study evaluated ponatinib in patients who were resistant or intolerant to nilotinib or dasatinib or patients who had the T315I mutation. In the Phase II study, ponatinib produced a major cytogenetic response in 54% of chronic phase chronic myeloid leukemia patients. It further achieved major hematologic response in 52% of patients in the accelerated phase, 31% of patients in the blast phase, and 41% of Philadelphia chromosome positive acute lymphoblastic leukemia patients. Ponatinib also showed efficacy in patients with the T315I mutation. Serious adverse events included arterial thrombosis, hepatotoxicity, cardiovascular risks, pancreatitis, hemorrhage, fluid retention, myelosuppression, rash, abdominal pain, and embryo–fetal toxicity. Due to the risk of these adverse events and potential drug interactions, the use of ponatinib must be carefully weighed against the benefits in treating patients who have limited treatment options.Keywords: BCR-ABL, tyrosine kinase inhibitor, TKI, T315I, Philadelphia chromosome

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

Adsorption and recovery of hexavalent uranium from dilute aqueous solutions by low cost citrus waste biomass was investigated by performing adsorption-desorption studies. Different samples of citrus waste biomasses were screened for removal of U(VI) from aqueous solutions. The results indicated that the biosorption capacity was strongly affected by the solution pH, biosorbent dose, contact time, and initial uranium concentration. Uranium binding by the test biomass was rapid, achieving >79% sorption efficiency within 15 min, and the equilibrium was established in 60 min. Optimum biosorption capacity (qe) was observed at pH 4.0, biosorbent dose 0.1 % (w/v), initial uranium concentration of 100 mg/L. The kinetic data fitted well to a pseudo-second-order rate equation (R2=0.980). The adsorption process conformed to a Langmuir adsorption isotherm model. Gibbs free energy (ΔGo) and enthalpy change (ΔHo) indicated that reaction was spontaneous and exothermic in nature at the studied temperatures. FT-IR studies showed the involvement of carbonyl, carboxyl, and amide groups in the biosorption process. Treatment of biomass with different reagents affected its biosorption capacity, and maximum removal (70.63%) was recorded with polyethyleneimine (PEI) treated biomass. EDTA had the best effects as an eluent, showing 94.7% desorption capacity.

Helminthes infections are now being recognized as the cause of many acute as well as chronic illnesses in human beings and in cattle, particularly in tropical and subtropical areas. The development of anthelmintic resistance and the high cost of conventional anthelmintic drugs led to evaluation of herbal remedies as alternative anthelmintic for the control of these parasites. In the current study, in vitro experiments were conducted to determine the possible anthelmintic effects of crude aqueous and methanolic extracts of Brassica nigra (seeds), Ocimum basilicum (whole plant) and Rumex abyssinicus (roots) in a dose of 20 and 40mg/ml against Eritrean adult earthworm Pheretima posthuma to justify the traditional claim using mebendazole as a reference standard. From the results, the paralysis and death time of worms in all extracts was found to be dose dependent and the potent anthelmintic activity was observed in aqueous extracts in comparison to methanolic extracts. Among the three plants Ocimum basilicum showed a potent anthelmintic activity with least paralysis time and death time, whereas Rumex abyssinicus extracts showed an intermediate activity and Brassica nigra has taken long time for death of worms. All the values were found to be statistically significant with P value of 0.00 using one way ANOVA. Based on the findings it may be concluded that Brassica nigra, Ocimum basilicum and Rumex abyssinicus possess varying degree of anthelmintic activity and also justifies its folklore claims for potential anthelmintic property.

Challenges face the Internet Architecture in order to scale to a greater number of users while providing a suite of increasingly essential functionality, such as multi-homing, traffic engineering, mobility, localised addressing and end-to-end packet-level security. Such functions have been designed and implemented mainly in isolation and retrofitted to the original Internet architecture. The resulting engineering complexity has caused some to think of 'clean slate' designs for the long-term future. Meanwhile, we take the position that an evolutionary approach is possible for a practical and scaleable interim solution, giving much of the functionality required, being backwards compatible with the currently deployed architecture, with incremental deployment capability, and which can reduce the current routing state overhead for the core network. By enhancing the way we use naming in the Internet Architecture, it is possible to provide a harmonised approach to multi-homing, traffic engineering, mobility, localised addressing and end-to-end packet-level security, including specific improvement to the scalability of inter-domain routing, and have these functions co-exist harmoniously with reduced engineering complexity. A set of proposed enhancements to the current Internet Architecture, based on naming, are described and analysed, both in terms of architectural changes and engineering practicalities.

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.

In the present study glucose oxidase (GOD) has been isolated from a culture filtrate of Penicillium notatum. The enzyme was purified by ammonium sulphate precipitation, diethylaminoethyl (DEAE) cellulose ion-exchange chromatography and Sephadex gel filtration. This protocol gave 16.47-fold purification and 25 % recovery of the enzyme. The optimum pH and temperature for the activity were 5.4 and 45 °C, respectively. The Km and vmax values for the enzyme were 10.5 mM and 456 U/mg, respectively. A detailed kinetic study of thermal inactivation was carried out. Both enthalpy of activation (ΔH*) and entropy of activation (ΔS*) decreased at higher temperatures. Moreover, free energy of denaturation (ΔG*) increased at higher temperature, making the enzyme thermally stable. A possible explanation for the thermal inactivation of GOD at higher temperatures is also discussed.

Although there have been a number of performance studies of proactive mobile ad hoc network (MANET) routing protocols, little attention has been paid to the impacts of topology update strategies on routing performance. This paper presents an analysis of several topology update strategies for a proactive MANET routing protocol. The goal of this paper is to better understand how topology update strategies can contribute to topology maintenance in proactive MANETs and thus impact the overall performance, based on simulations involving optimised link state routing (OLSR), a popular MANET protocol. Our contribution includes (1) a quantitative analysis of the impacts of proactive update intervals on the routing performance of OLSR; (2) evaluating the performance of reactive topology updates and proactive updates for OLSR.

This work was partly supported by the IU-ATC project, funded by grant EP/J016756/1 from the Engineering and Physical Sciences Research Council (EPSRC). Chonlatee Khorakhun is funded by the Scottish Informatics and Computer Science Alliance (SICSA). We describe a user study of a mHealth prototype system based on a wellbeing scenario, exploiting the quantified-self approach to measurement and monitoring. We have used off-the-shelf equipment, with opensource, web-based, software, and exploiting the increasing popularity of smartphones and self-measurement devices in a user study. We emulate a mHealth scenario as a pre-clinical experiment, as a realistic alternative to a clinical scenario, with reduced risk to sensitive patient medical data. We discuss the efficacy of this approach for future mHealth systems for remote monitoring. Our system used the popular Fitbit device for monitoring personal wellbeing data, the Diaspora online social media platform (OSMP), and a simple Android/iOS remote notification application. We implemented remote monitoring, asynchronous user interaction, multiple actors, and user-controlled security and privacy mechanisms. We propose that the use of a quantified-self approach to mHealth is particularly valuable to undertake research and systems development. Postprint

Seamless host mobility has been a desirable feature for a long time, but was not part of the original design of the Internet architecture or protocols. Current approaches to network-layer mobility typically require additional network-layer entities for mobility management, which add complexity to the current engineering landscape of the Internet. We present a host-based, end-to-end architecture for host mobility using the Identifier-Locator Network Protocol (ILNP). ILNP provides mobility support as a first class function, since mobility management is controlled and managed by the end-systems, and does not require additional network-layer entities. We demonstrate an instance of ILNP that is a superset of IPv6 – called ILNPv6 – that is implemented by extending the current IPv6 code in the Linux kernel. We make a direct comparison of performance of ILNPv6 and Mobile IPv6, showing the improved performance of ILNPv6. Postprint

In mature wireless LAN (WLAN) deployments, we show that introducing 802.11ac could have little benefit compared to existing 802.11n deployments. Using a testbed with common characteristics for a WLAN deployment, we compare throughput for 802.11ac and 802.11n (in both 5GHz and 2.4GHz bands). We find that 802.11ac has lower throughput than for 802.11n for our testbed configuration. We also provide an evaluation of energy usage for 802.11ac and 802.11n.

Mesh networking has recently received considerable attention, largely as a mechanism for providing enhanced connectivity without the need to install additional expensive infrastructure. It relies on the fact that underutilised local area connectivity can be used to connect constrained devices to those that possess wide-area uplink capabilities. However, at present, proposals for uplink bandwidth sharing are limited by the use of a traditional view of routing in which multiple end-user devices are associated with each individual uplink in such a way that all their off-network traffic is routed through that particular gateway. While this has the merit of simplicity, it is possible for a subset of gateways to be overloaded while others remain underutilised. We propose a new type of local mesh network, called the Coalition Peering Domain, the goal of which is to maximise Internet connectivity dynamically, smoothing out the usage of uplink capacity, albeit at the cost of slightly more complex control and management. Within this paper, we describe three main routing and addressing issues and then propose novel mechanisms that partially address those issues.

We live in a world in which there is a great disparity between the lives of the rich and the poor. Information and communication technology (ICT) offers promise in bridging this digital divide through its focus on connecting human capacity with computing and informational content. It is well known that Internet access has the capability of fostering development and growth by enabling access to information, education, and opportunities. Unfortunately, the availability of Internet in worldwide terms is limited, with an estimated 4 billion people - an estimated 60 percent of the human population - lacking Internet access. People in rural areas are particularly hard hit since socio-economic factors preclude the provisioning of Internet access and mobile telephony in these sparsely populated low-income areas.

This paper reports on different efforts to provide quality of service (QoS) Networking to Grid applications done in the context of the MB-NG, GRS and DataTAG EU projects. These are leading edge network research projects involving more that 50 researchers in the UK, Europe and North America, concerned with the development and testing of protocols and standards for the next generation of high speed networks. We have implemented and tested the Differentiated Services Architecture (DiffServ) in a multi-domain, 2.5 Gbits/s network (the first such deployment) defining appropriate Service Level Agreements (SLAs) to be used between administrative domains to guarantee end-to-end Quality of Service. We characterised several hardware implementations of DiffServ and concluded on their appropriateness for several network scenarios. Since current and future Grid applications will have to use modified mechanisms of congestion control we have evaluated old and new TCP implementations over a Differentiated Services Networks. These quality of service tests have also included innovative MPLS (Multi-Protocol Label Switching) experiments to establish guaranteed bandwidth connections to Grid applications in a fast and efficient way. We have also developed a software based bandwidth broker architecture for Grids based on IETF standards which allows applications to transparently request dynamic and advanced reservations and implemented it in a real experimental network. We finally report on experiences delivering Quality of Service networking to high performance applications like Particle Physics data transfer and High Performance Computation. This includes quantitative results on the performance improvements that QoS brought to real data transfers in the context of High Performance Computing.

Chonlatee Khorakhun was funded by the Scottish Informatics and Computer Science Alliance (SICSA). Remote monitoring is an essential part of future mHealth systems for the delivery of personal and pervasive healthcare, especially to allow the collection of personal bio-data outside clinical environments. Yet, by its very nature, it presents considerable challenges: it will be a highly distributed task, requiring collection of bio-data for a myriad of cources, to be marshalled at the clinical site via secure communication channels. To address these challenges, we propose the use of an online social media platform (OSMP) as a key component of a near-future remote health monitoring system. By exploiting existing infrastructure, initial costs can be reduced, at the same time as allowing fast and flexible application development. An OSMP would have user benefits also: patients and healthcare professionals can be presented with familiar interfaces, while application developers can work with a set of technologies that are widely used and well-known. Internet-based access also helps to provide wide-ranging connectivity for mobile applications. Additionally, the use of a social media context allows existing social interactions within the healthcare regime to be modelled within a em carer network, working in harmony with, and providing support for, existing relationships and interactions between patients and healthcare professionals. We focus on the use of an OSMP to enable two primitive functions which we consider essential for mHealth, and on which larger personal healthcare services could be built: em remote health monitoring of personal bio-data, and an em alert system for asynchronous notifications. We analyse the general requirements in a carer network for these two primitive functions, in terms of four different viewpoints within the carer network: the em patient, the em doctor in charge, a professional em carer, and a em family member (or friend) of the patient. We discuss the suitability of OSMPs in terms of functionality, performance, security privacy, as well as the potential for cost reduction. Publisher PDF

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.

We describe a mechanism for fast, secure failover for IP. The mechanism is invisible to end-systems: sessions are maintained during failover. Our novel approach is to model the failover as a mobility problem, and use a mobility solution in order to implement change in connectivity. Our system is based on the Identity Locator Network Protocol (ILNP), an Experimental IRTF protocol which is realised as superset of IPv6. Our empirical results from a test bed emulation show that there is almost zero gratuitous loss during failover.

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.

IP-based networks were never designed for real time traffic, yet QoS support in such networks is needed to accommodate both global use and the more demanding applications now emerging. Changes in packet handling, in particular, will help provide QoS support in IP networks. The article focuses on the issues and principles concerning router modification for IP packet handling.

We present a network model that allows processing of QoS (quality of service) information about media flows to enable applications to make adaptation decisions. Our model is based around a multi-dimensional spatial representation that allows QoS information describing the flow constructions and QoS parameters – flow-states – to interact with a representation of the network QoS. The model produces reports about the compatibility between the flow-states and the network QoS, indicating which flow-states the network can currently support. The simple nature of the reports allows the application to make decisions, dynamically, on which flow-state it should use. The model is relatively lightweight and scaleable. We demonstrate the use of the model by simulation of a dynamically adaptive audio tool. Our work is ongoing.

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.

Remote monitoring is considered an essential part of future eHealth systems to enable the delivery of healthcare outside clinical sites at reduced cost, while improving quality of patient care. We examine the use of online social networks for remote health monitoring. By exploiting the existing infrastructure, initial costs can be reduced and fast application development is possible. Facebook is used as an example platform: as a platform allowing user-defined applications, development is flexible and can be arranged quickly to suit different requirements of patients and health professionals. We analyse the general requirements of a remote monitoring scenario and the process of building and using a Facebook application to meet these requirements. Four different access viewpoints are implemented to suit the requirements of each user in our example scenario to form a carer network: the patient, the doctor in charge, professional carers, and family members of the patient. The suitability of the application is analysed including security and privacy issues. We conclude that online social media systems could offer a suitable platform for developing certain types of remote monitoring capability.

In recent years, there has been an upsurge of research interest in cooperative wireless communications in both academia and industry. This article presents a simple overview of the pivotal topics in both mobile station (MS)- and base station (BS)- assisted cooperation in the context of cellular radio systems. Owing to the ever-increasing amount of literature in this particular field, this article is by no means exhaustive, but is intended to serve as a roadmap by assembling a representative sample of recent results and to stimulate further research. The emphasis is initially on relay-base cooperation, relying on network coding, followed by the design of cross-layer cooperative protocols conceived for MS cooperation and the concept of coalition network element (CNE)-assisted BS cooperation. Then, a range of complexity and backhaul traffic reduction techniques that have been proposed for BS cooperation are reviewed. A more detailed discussion is provided in the context of MS cooperation concerning the pros and cons of dispensing with high-complexity, power-hungry channel estimation. Finally, generalized design guidelines, conceived for cooperative wireless communications, are presented.

Widespread use of wireless LAN (WLAN) may soon cause an over-crowding problem in use of the ISM spectrum. One way in which this manifests itself is the low Received Signal Strength Indication (RSSI) at the WLAN stations, impacting performance. Meanwhile, the IEEE 802.11 standard is being evolved and extended, for example with new coding schemes and the 802.11n standard, which makes use of 5GHz and 2.4GHz. An application's performance requirements may dictate the choice of technology determined by RSSI levels. We report on measurements of the upper and lower bounds of performance with good and poor RSSI in 802.11g and 802.11n. We find that in operation under poor (low) RSSI, performance is indeed impacted. In some cases the impact is such that there may be little benefit in using the newer 802.11n over 802.11g.

We demonstrate that in a future converged network scenario, it may be beneficial to allow selection of 802.11 variant based on application requirements. We analyse traces from the campus network from the University of Twente, comprising ~5000 users. We have evaluated a performance envelope derived from testbed experiments for individual IEEE 802.11 variants and compare these with the traffic patterns from the campus network. From our comparison, we find that specific IEEE 802.11 variants (e.g. 802.11g or 802.11n) may be better suited to specific applications, such as video streaming, rather than using a single WLAN standard for all traffic.

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.