Training deep learning models, particularly Transformer-based architectures such as Large Language Models (LLMs), demands substantial computational resources and extended training periods. While optimal configuration and infrastructure selection can significantly reduce associated costs, this optimization requires preliminary analysis tools. This paper introduces PreNeT, a novel predictive framework designed to address this optimization challenge. PreNeT facilitates training optimization by integrating comprehensive computational metrics, including layer-specific parameters, arithmetic operations and memory utilization. A key feature of PreNeT is its capacity to accurately predict training duration on previously unexamined hardware infrastructures, including novel accelerator architectures. This framework employs a sophisticated approach to capture and analyze the distinct characteristics of various neural network layers, thereby enhancing existing prediction methodologies. Through proactive implementation of PreNeT, researchers and practitioners can determine optimal configurations, parameter settings, and hardware specifications to maximize cost-efficiency and minimize training duration. Experimental results demonstrate that PreNeT achieves up to 72% improvement in prediction accuracy compared to contemporary state-of-the-art frameworks.

With the advent of 5G networks and the rise of the Internet of Things (IoT), Content Delivery Networks (CDNs) are increasingly extending into the network edge. This shift introduces unique challenges, particularly due to the limited cache storage and the diverse request patterns at the edge. These edge environments can host traffic classes characterized by varied object-size distributions and object-access patterns. Such complexity makes it difficult for traditional caching strategies, which often rely on metrics like request frequency or time intervals, to be effective. Despite these complexities, the optimization of edge caching is crucial. Improved byte hit rates at the edge not only alleviate the load on the network backbone but also minimize operational costs and expedite content delivery to end-users. In this paper, we introduce HR-Cache, a comprehensive learning-based caching framework grounded in the principles of Hazard Rate (HR) ordering, a rule originally formulated to compute an upper bound on cache performance. HR-Cache leverages this rule to guide future object eviction decisions. It employs a lightweight machine learning model to learn from caching decisions made based on HR ordering, subsequently predicting the "cache-friendliness'' of incoming requests. Objects deemed "cache-averse'' are placed into cache as priority candidates for eviction. Through extensive experimentation, we demonstrate that HR-Cache not only consistently enhances byte hit rates compared to existing state-of-the-art methods but also achieves this with minimal prediction overhead. Our experimental results, using three real-world traces and one synthetic trace, indicate that HR-Cache consistently achieves 2.2-14.6% greater WAN traffic savings than LRU. It outperforms not only heuristic caching strategies but also the state-of-the-art learning-based algorithm.

Analytical performance models are very effective in ensuring the quality of service and cost of service deployment remain desirable under different conditions and workloads. While various analytical performance models have been proposed for previous paradigms in cloud computing, serverless computing lacks such models that can provide developers with performance guarantees. Besides, most serverless computing platforms still require developers’ input to specify the configuration for their deployment that could affect both the performance and cost of their deployment, without providing them with any direct and immediate feedback. In previous studies, we built such performance models for steady-state and transient analysis of scale-per-request serverless computing platforms (e.g., AWS Lambda, Azure Functions, Google Cloud Functions) that could give developers immediate feedback about the quality of service and cost of their deployments. In this work, we aim to develop analytical performance models for latest trend in serverless computing platforms that use concurrency value and the rate of requests per second for autoscaling decisions. Examples of such serverless computing platforms are Knative and Google Cloud Run (a managed Knative service by Google). The proposed performance model can help developers and providers predict the performance and cost of deployments with different configurations which could help them tune the configuration toward the best outcome. We validate the applicability and accuracy of the proposed performance model by extensive real-world experimentation on Knative and show that our performance model is able to accurately predict the steady-state characteristics of a given workload with minimal amount of data collection.

Function-as-a-Service (FaaS) has become a mainstream cloud computing paradigm for developers to build cloud-native applications in recent years. By taking advantage of serverless architecture, FaaS applications bring many desirable benefits, including built-in scalability, high availability, and improved cost-effectiveness. However, predictability and trade-off of performance and cost are still key pitfalls for FaaS applications due to poor infrastructure transparency and lack of performance and cost models that fit the new paradigm. In this study, we therefore fill this gap by proposing formal performance and cost modeling and optimization algorithms, which enable accurate prediction and fine-grained control over the performance and cost of FaaS applications. The proposed model and algorithms provide better predictability and trade-off of performance and cost for FaaS applications, which help developers to make informed decisions on cost reduction, performance improvement, and configuration optimization. We validate the proposed model and algorithms via extensive experiments on AWS. We show that the modeling algorithms can accurately estimate critical metrics, including response time, cost, exit status, and their distributions, regardless of the complexity and scale of the application workflow. Also, the depth-first bottleneck alleviation algorithm for trade-off analysis can effectively solve two optimization problems with fine-grained constraints.

Serverless computing has emerged in recent years as the new computing paradigm adopted by key players in the industry for software development. This new paradigm has seen rapid growth in adoption due to its unique billing model and scaling characteristics. Public cloud providers such as Amazon Web Services (AWS) offer several configurations and language runtimes for their serverless functions. Although extensively explored by the research community, this field still lacks current studies that address the many challenges developers face when leveraging serverless functions for real-world applications. One of these challenges that are often overseen by many programmers is the cold start problem which is present in any serverless application. For this reason, we propose the first study to characterize the underlying cold start impacts caused by the choice of language runtime, application size, memory size and deployment type on AWS Lambda. In this paper, we analyze the performance of the container-based deployment and ZIP-based deployment of AWS Lambda using a variety of language runtimes and applications running with different function configurations; then we propose guidelines for developers and cloud managers to consider when deploying/managing the workloads on the cloud.

Microservice architecture has transformed the way developers are building and deploying applications in the nowadays cloud computing centers. This new approach provides increased scalability, flexibility, manageability, and performance while reducing the complexity of the whole software development life cycle. The increase in cloud resource utilization also benefits microservice providers. Various microservice platforms have emerged to facilitate the DevOps of containerized services by enabling continuous integration and delivery. Microservice platforms deploy application containers on virtual or physical machines provided by public/private cloud infrastructures in a seamless manner. In this article, we study and evaluate the provisioning performance of microservice platforms by incorporating the details of all layers (i.e., both micro and macro layers) in the modeling process. To this end, we first build a microservice platform on top of Amazon EC2 cloud and then leverage it to develop a comprehensive performance model to perform what-if analysis and capacity planning for microservice platforms at scale. In other words, the proposed performance model provides a systematic approach to measure the elasticity of the microservice platform by analyzing the provisioning performance at both the microservice platform and the back-end macroservice infrastructures.

Analytical performance models have been leveraged extensively to analyze and improve the performance and cost of various cloud computing services. However, in the case of serverless computing, which is projected to be the dominant form of cloud computing in the future, we have not seen analytical performance models to help with the analysis and optimization of such platforms. In this work, we propose an analytical performance model that captures the unique details of serverless computing platforms. The model can be leveraged to improve the quality of service and resource utilization and reduce the operational cost of serverless platforms. Also, the proposed performance model provides a framework that enables serverless platforms to becomeworkload-awareand operate differently for different workloads to provide a better trade-off between the cost and performance depending on the user's preferences. The current serverless offerings require the user to have extensive knowledge of the internals of the platform to perform efficient deployments. Using the proposed analytical model, the provider can simplify the deployment process by calculating the performance metrics for users even before physical deployments. We validate the applicability and accuracy of the proposed model by extensive experimentation on AWS Lambda. We show that the proposed model can calculate essential performance metrics such as average response time, probability of cold start, and the average number of function instances in the steady-state. Also, we show how the performance model can be used to tune the serverless platform for each workload, which will result in better performance or lower cost without scarifying the other. The presented model assumes no non-realistic restrictions, so that it offers a high degree of fidelity while maintaining tractability at large scale.

The abundance of data collected by sensors in Internet of Things (IoT) devices, and the success of deep neural networks in uncovering hidden patterns in time series data have led to mounting privacy concerns. This is because private and sensitive information can be potentially learned from sensor data by applications that have access to this data. In this paper, we aim to examine the tradeoff between utility and privacy loss by learning low-dimensional representations that are useful for data obfuscation. We propose deterministic and probabilistic transformations in the latent space of a variational autoencoder to synthesize time series data such that intrusive inferences are prevented while desired inferences can still be made with sufficient accuracy. In the deterministic case, we use a linear transformation to move the representation of input data in the latent space such that the reconstructed data is likely to have the same public attribute but a different private attribute than the original input data. In the probabilistic case, we apply the linear transformation to the latent representation of input data with some probability. We compare our technique with autoencoder-based anonymization techniques and additionally show that it can anonymize data in real time on resource-constrained edge devices.

Developing accurate and extendable performance models for serverless platforms, aka Function-as-a-Service (FaaS) platforms, is a very challenging task. Also, implementation and experimentation on real serverless platforms is both costly and time-consuming. However, at the moment, there is no comprehensive simulation tool or framework to be used instead of the real platform. As a result, in this paper, we fill this gap by proposing a simulation platform, called SimFaaS, which assists serverless application developers to develop optimized Function-as-a-Service applications in terms of cost and performance. On the other hand, SimFaaS can be leveraged by FaaS providers to tailor their platforms to be workload-aware so that they can increase profit and quality of service at the same time. Also, serverless platform providers can evaluate new designs, implementations, and deployments on SimFaaS in a timely and cost-efficient manner. SimFaaS is open-source, well-documented, and publicly available, making it easily usable and extendable to incorporate more use case scenarios in the future. Besides, it provides performance engineers with a set of tools that can calculate several characteristics of serverless platform internal states, which is otherwise hard (mostly impossible) to extract from real platforms. We show how SimFaaS facilitates the prediction of essential performance metrics such as average response time, probability of cold start, and the average number of instances reflecting the infrastructure cost incurred by the serverless computing provider. We evaluate the accuracy and applicability of SimFaaS by comparing the prediction results with real-world traces from Amazon AWS Lambda.

The Ninth International Workshop on Load Testing and Benchmarking of Software Systems (LTB 2021) is a full-day virtual event bringing together software testing researchers, practitioners and tool developers to discuss the challenges and opportunities of conducting research on load testing and benchmarking software systems. The workshop, co-located with the 12th International Conference on Performance Engineering (ICPE 2021), is held on April 19th, 2021 in Rennes, France.

Embedded sensors and smart devices have turned the environments around us into smart spaces that could automatically evolve, depending on the needs of users, and adapt to the new conditions. While smart spaces are beneficial and desired in many aspects, they could be compromised and expose privacy, security, or render the whole environment a hostile space in which regular tasks cannot be accomplished anymore. In fact, ensuring the security of smart spaces is a very challenging task due to the heterogeneity of devices, vast attack surface, and device resource limitations. The key objective of this study is to minimize the manual work in enforcing the security of smart spaces by leveraging the autonomic computing paradigm in the management of IoT environments. More specifically, we strive to build an autonomic manager that can monitor the smart space continuously, analyze the context, plan and execute countermeasures to maintain the desired level of security, and reduce liability and risks of security breaches. We follow the microservice architecture pattern and propose a generic ontology named Secure Smart Space Ontology (SSSO) for describing dynamic contextual information in security-enhanced smart spaces. Based on SSSO, we build an autonomic security manager with four layers that continuously monitors the managed spaces, analyzes contextual information and events, and automatically plans and implements adaptive security policies. As the evaluation, focusing on a current BlackBerry customer problem, we deployed the proposed autonomic security manager to maintain the security of a smart conference room with 32 devices and 66 services. The high performance of the proposed solution was also evaluated on a large-scale deployment with over 1.8 million triples.

Function-as-a-Service (FaaS) and serverless applications have proliferated significantly in recent years because of their high scalability, ease of resource management, and pay-as-you-go pricing model. However, cloud users are facing practical problems when they migrate their applications to the serverless pattern, which are the lack of analytical performance and billing model and the trade-off between limited budget and the desired quality of service of serverless applications. In this article, we fill this gap by proposing and answering two research questions regarding the prediction and optimization of performance and cost of serverless applications. We propose a new construct to formally define a serverless application workflow, and then implement analytical models to predict the average end-to-end response time and the cost of the workflow. Consequently, we propose a heuristic algorithm named Probability Refined Critical Path Greedy algorithm (PRCP) with four greedy strategies to answer two fundamental optimization questions regarding the performance and the cost. We extensively evaluate the proposed models by conducting experimentation on AWS Lambda and Step Functions. Our analytical models can predict the performance and cost of serverless applications with more than 98 percent accuracy. The PRCP algorithms can achieve the optimal configurations of serverless applications with 97 percent accuracy on average.

This paper presents a novel big data analytics framework for creating explainable personas for retail and business banking customers. These personas are essential to better tailor financial products and improve customer retention. This framework is comprised of several components including anomaly detection, binning and aggregation of contextual data, clustering of transaction time series, and mining association rules that map contextual data to cluster identifiers. Leveraging rich transaction and contextual data available from nearly 60,000 retail and 90,000 business customers of a financial institution, we empirically evaluate this framework and describe how the identified association rules can be used to explain and refine existing customer classes, and identify new customer classes and various data quality issues. We also analyze the performance of the proposed framework and show that it can easily scale to millions of banking customers.

Docker is currently one of the most popular containerization solutions. Previous work investigated various characteristics of the Docker ecosystem, but has mainly focused on Dockerfiles from GitHub, limiting the type of questions that can be asked, and did not investigate evolution aspects. In this paper, we create a recent and more comprehensive data set by collecting data from Docker Hub, GitHub, and Bitbucket. Our data set contains information about 3,364,529 Docker images and 378,615 git repositories behind them. Using this data set, we conduct a large-scale empirical study with four research questions where we reproduce previously explored characteristics (e.g., popular languages and base images), investigate new characteristics such as image tagging practices, and study evolution trends. Our results demonstrate the maturity of the Docker ecosystem: we find more reliance on ready-to-use language and application base images as opposed to yet-to-be-configured OS images, a downward trend of Docker image sizes demonstrating the adoption of best practices of keeping images small, and a declining trend in the number of smells in Dockerfiles suggesting a general improvement in quality. On the downside, we find an upward trend in using obsolete OS base images, posing security risks, and find problematic usages of the latest tag, including version lagging. Overall, our results bring good news such as more developers following best practices, but they also indicate the need to build tools and infrastructure embracing new trends and addressing potential issues.

With the increasing popularity and complexity of containerized software systems, satisfying the performance requirements of these systems becomes more challenging as well. While a common remedy to this problem is to increase the allocated amount of resources by scaling up or out, this remedy is not necessarily cost-effective and, therefore, often problematic for smaller companies. In this paper, we study an alternative, more cost-effective approach for satisfying the performance requirements of containerized software systems. In particular, we investigate how we can satisfy such requirements by applying software multi-versioning to the system's resource-heavy containers. We present DockerMV, an open-source extension of the Docker framework, to support the multi-versioning of containerized software systems. We demonstrate the efficacy of multi-versioning for satisfying the performance requirements of containerized software systems through experiments on the TeaStore, a microservice reference test application, and Znn, a containerized news portal application. Our DockerMV extension can be used by software developers to introduce multi-versioning in their own containerized software systems, thereby better allowing them to meet the performance requirements of their systems.

The Eighth International Workshop on Load Testing and Benchmarking of Software Systems (LTB 2020) is a full-day event bringing together software testing researchers, practitioners and tool developers to discuss the challenges and opportunities of conducting research on load testing and benchmarking software systems. The workshop, co-located with the 11th International Conference on Performance Engineering (ICPE 2020), is held on April 20th, 2020 in Edmonton, Alberta, Canada.

Control theory has proven to be a practical approach for the design and implementation of controllers, which does not inherit the problems of non-control theoretic controllers due to its strong mathematical background. State-of-the-art auto-scaling controllers suffer from one or more of the following limitations: (1) lack of a reliable performance model, (2) using a performance model with low scalability, tractability, or fidelity, (3) being application- or architecture-specific leading to low extendability, and (4) no guarantee on their efficiency. Consequently, in this article, we strive to mitigate these problems by leveraging an adaptive controller, which is composed of a neural network as the performance model and a Proportional-Integral-Derivative (PID) controller as the scaling engine. More specifically, we design, implement, and analyze different flavours of these adaptive and non-adaptive controllers, and we compare and contrast them against each other to find the most suitable one for managing containerized cloud software systems at runtime. The controller’s objective is to maintain the response time of the controlled software system in a pre-defined range, and meeting the Service-level Agreements, while leading to efficient resource provisioning.

This paper presents an adaptive service management mechanism that maintains service level agreement through use of overlay networks that are deployed over the cloud provider network. The application autonomic manager strives to maintain the SLA without provisioning new resources for as long as possible. Through continuous monitoring and analysis, autonomic manager uses software defined networking (SDN) to dynamically apply policies to the flows of requests that travel through the application components. We implement and evaluate the proposed method on a hybrid cloud environment. Through extensive experiments, we show that the management mechanism can successfully maintain the SLA of services while it avoids provisioning extra resources which is the common approach in cloud.

In this paper, we present an architecture and implementation for self-managing cloud application using overlay networks and software defined networking (SDN). Through real world experiments on Amazon EC2 and Smart Applications on Virtual Infrastructure (SAVI) cloud, we demonstrate how our management mechanism autonomously maintains SLAs of application scenarios without provisioning extra resources.

Cloudification, softwarization and edge processing are been heavily adopted to design, implement and deploy IoT applications at scale. Building upon our previous initiatives and incorporating the above-mentioned paradigm, we propose and demonstrate a hierarchical, programmable and autonomic IoT platform that deploys highly distributed, manageable and efficient IoT applications in a softwaredefined manner. The platform leverages both cloud microservices and macroservices to support big data, local/edge data processing, high level of programmability and runtime autonomic management.

Microservice architecture has started a new trend for application development/deployment in cloud due to its flexibility, scalability, manageability and performance. Various microservice platforms have emerged to facilitate the whole software engineering cycle for cloud applications from design, development, test, deployment to maintenance. In this paper, we propose a performance analytical model and validate it by experiments to study the provisioning performance of microservice platforms. We design and develop a microservice platform on Amazon EC2 cloud using Docker technology family to identify important elements contributing to the performance of microservice platforms. We leverage the results and insights from experiments to build a tractable analytical performance model that can be used to perform what-if analysis and capacity planning in a systematic manner for large scale microservices with minimum amount of time and cost.

Distributed Denial of Service (DDoS) attacks are one of the main concerns for online service providers because of their impact on cost/revenue and reputation. This paper presents Completely Automated DDoS Attack Mitigation Platform (CAAMP), a novel platform to mitigate DDoS attacks on public cloud applications using capabilities of software defined infrastructure and network function virtualization techniques. When suspicious traffic is identified, CAAMP deploys a copy of the application's topology on-the-fly (a shark tank) on an isolated environment in a private cloud. It then creates a virtual network that will host the shark tank. Software defined networking (SDN) controller programs the virtual switches dynamically to redirect the suspicious traffic to the shark tank until final decision is made. If traffic is proved to be non-malicious, SDN controller installs flow rules on the switches to redirect the traffic back to the original application. Thus, CAAMP autonomically protects applications against potential DDoS threats and lowers the false positives associated with common detection mechanisms by leveraging resources from a private cloud.

Smart grid is expected to improve the efficiency, reliability and economics of current energy systems. Using two-way flow of electricity and information, smart grid builds an automated, highly distributed energy delivery network. In this paper, we present the requirements for intrusion detection systems (IDSs) in neighborhood area network (NAN) as a component of smart grid. We propose an IDS that is implemented in a distributed fashion with respect to NAN's communication and computation needs. An analytical approach is employed for detecting Wormhole attacks. We validate our NAN IDS scheme using OPNET Modeler [1]. The analytical part of the solution is developed in Maple [2] and integrated with OPNET.

High speed physiological data produced by medical devices at intensive care units (ICUs) has all the characteristics of Big Data. The proper use and management of such data can promote the health and reduces mortality and disability rates of critical condition patients. The effective use of Big Data within ICUs has great potential to create new cloud-based health analytics solutions for disease prevention or earlier condition onset detection. The Artemis project aims to achieve the above goals in the area of neonatal intensive care units (NICU). In this paper, we proposed an analytical model for an extended version of Artemis system which is being deployed at SickKids hospital in Toronto. Using the proposed analytical model, we predict the amount of storage, memory and computation power required for Artemis. In addition, important performance metrics such as mean number of patients in the NICU, blocking probability and mean patient residence time for different configurations are obtained. Capacity planning and trade-off analysis would be more accurate and systematic by applying the proposed analytical model in this paper. Numerical results are obtained using real inputs acquired from a pilot deployment of the system at SickKids hospital.

Advanced metering infrastructure AMI is one of the key elements in smart grid, which facilitates the communication of metering data to a substation in one direction and control messages in the reverse direction. Using wireless technologies and communication devices e.g., smart meters, which are located in the physically insecure places, makes the AMI vulnerable to cyber attacks. In order to ensure the reliability and security of AMI, attack prevention techniques and intrusion detection systems IDSs should be in place to protect the AMI communications from malicious attacks and security breaches, respectively. In this paper, we discuss the security requirements and vulnerabilities of AMI and review the existing threat prevention and detection solutions. We propose an IDS for neighborhood area network NAN in AMI, taking into account the NAN-specific requirements. Copyright © 2012 John Wiley & Sons, Ltd.

Cloud centers often use virtualization which requires live migration of virtual machines to improve performance and availability. In this paper, we describe an analytical performance model that measures the important performance indicators, namely, rejection probability and total delay, of a cloud center whilst taking into account live migration of virtual machines. Using the proposed performance model, we show that live virtual machine migration reduces task rejection probability and renders the super-task delay nearly independent of mean service time of individual tasks in a super-task.

Accurate performance evaluation of cloud computing resources is a necessary prerequisite for ensuring that quality of service parameters remain within agreed limits. In this paper, we employ both the analytical and simulation modeling to addresses the complexity of cloud computing systems. Analytical model is comprised of distinct functional submodels, the results of which are combined in an iterative manner to obtain the solution with required accuracy. Our models incorporate the important features of cloud centers such as batch arrival of user requests, resource virtualization, and realistic servicing steps, to obtain important performance metrics such as task blocking probability and total waiting time incurred on user requests. Also, our results reveal important insights for capacity planning to control delay of servicing users requests.

In this paper, we evaluate the performance of cloud centers with high degree of virtualization and Poisson batch task arrivals. To this end, we develop an analytical model and validate it with an independent simulation model. Task service times are modeled with a general probability distribution, but the model also accounts for the deterioration of performance due to the workload at each node. The model allows for calculation of important performance indicators such as mean response time, waiting time in the queue, queue length, blocking probability, probability of immediate service, and probability distribution of the number of tasks in the system. Furthermore, we show that the performance of a cloud center may be improved if incoming requests are partitioned on the basis of the coefficient of variation of service time and batch size.

In this paper, we propose an analytical performance model that addresses the complexity of cloud centers through distinct stochastic submodels, the results of which are integrated to obtain the overall solution. Our model incorporates the important aspects of cloud centers such as pool management, compound requests (i.e., a set of requests submitted by one user simultaneously), resource virtualization and realistic servicing steps. In this manner, we obtain not only a detailed assessment of cloud center performance, but also clear insights into equilibrium arrangement and capacity planning that allows servicing delays, task rejection probability, and power consumption to be kept under control.

Accurate availability and performance analysis are important requirements to guarantee quality of services (QoS) for cloud users. In this paper, we integrate an availability model in overall analytical sub-models of cloud system. Each sub-model captures a specific aspect of cloud centers. The key performance metrics such as task blocking probability and total delay incurred on user tasks are obtained. Our results can be used by an admission control to prevent the cloud center from entering unstable regime of operation. The results also reveal practical insights into capacity planning for cloud computing centers.

Successful development of cloud computing paradigm necessitates accurate performance evaluation of cloud data centers. As exact modeling of cloud centers is not feasible due to the nature of cloud centers and diversity of user requests, we describe a novel approximate analytical model for performance evaluation of cloud server farms and solve it to obtain accurate estimation of the complete probability distribution of the request response time and other important performance indicators. The model allows cloud operators to determine the relationship between the number of servers and input buffer size, on one side, and the performance indicators such as mean number of tasks in the system, blocking probability, and probability that a task will obtain immediate service, on the other.

Quality of service, QoS, has a great impact on wider adoption of cloud computing. Maintaining the QoS at an acceptable level for cloud users requires an accurate and well adapted performance analysis approach. In this paper, we describe a new approximate analytical model for performance evaluation of cloud server farms under burst arrivals and solve it to obtain important performance indicators such as mean request response time, blocking probability, probability of immediate service and probability distribution of number of tasks in the system. This model allows cloud operators to tune the parameters such as the number of servers and/or burst size, on one side, and the values of blocking probability and probability that a task request will obtain immediate service, on the other.

Due to lack of an appropriate wireless technology which satisfies all the requirements of Wireless Body Area Networks (WBANs) the IEEE 802.15.6 Task Group introduced the IEEE 802.15.6 communication standard optimized for low power devices and operation on, in or around the human body. In this work we develop an analytical model for performance evaluation of an IEEE 802.15.6-based WBAN under saturation condition and error prone channel. We model the backoff procedure as specified in the standard employing a probabilistic approach. We validate results of the analytical model with a simulation model. Our results indicate that under saturation condition the medium is mostly utilized by the nodes with highest priority while other user priorities are starving.