BARTAP. Bandwidth Available in Real Time measurement APplications

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1 BARTAP Bandwidth Available in Real Time measurement APplications (BARTAPP - Tillämpningar av tillgänglig bandbreddsmätning i realtid) Abstract An application to VINNOVAs call Mobilitet, mobil kommunikation och bredband Område: Framväxt av tjänster i nät och terminaler Utvärdering av nya teknologier och tjänster Proposer: Mats Björkman Mälardalens högskola Partners: Mälardalens högskola, Ericsson AB, SICS AB For communication network operators, the costs for operating the network (opex) are typically higher than the capital costs of the network equipment (capex). With the advanced and highly complex network environment of today and tomorrow, it is becoming increasingly important to develop methods and applications for more efficient network operation (and thus reduction of opex). The BARTAP project proposes application of methods for computer network performance measurements. It leverages on the past VINNOVA-sponsored EvaluNet project, as well on the recently approved EU FP7 project MOMENT starting in January The EvaluNet project successfully resulted in an international patent application on the fundamental measurement technology, BART. BARTAP proposes using this technology in application areas of interest for network operators and end users. The BART method of network measurement, developed in the EvaluNet project, will be central to BARTAP, and a key point of BARTAP is to concretely prove the feasibility of BART in commercial products. Two application areas are targeted in BARTAP, network management and end-user applications. For network management, network measurement applications should be deployed at important points inside the network, e.g. in special boxes or running on exiting network management nodes. For end-user applications, e.g. streaming media, network measurement tools can be embedded into the main application. Doing this, measurements can be performed using the main application traffic instead of special measurement traffic. Also, the main application could get direct feedback from the measurements, allowing for proactive adjustment of the application traffic. Main technology areas The main technical areas of the proposed BARTAP project are measurements and estimations of network characteristics. The main characteristic studied this far is available bandwidth, but also parameters such as one-way delay, delay jitter, and packet loss will be of importance for the BARTAP project. All of these are important characteristics for media applications, one of the application areas targeted in the BARTAP project. Measurements are performed as active measurements, where probe packets are injected into the network. For end-to-end applications of bandwidth estimation, user application data can be used as probe packets, thus avoiding injecting extra traffic into the network. The BART method that will be used as a basis for the BARTAP project, uses advanced filtering that allows real-time recursive estimation of available bandwidth.

2 Targeted application areas Two application areas are targeted in BARTAP, network management and end-user applications. Network management applications refer to programs that allow the network operators to administer the network effectively. Such applications may be deployed at important points inside the network, e.g. in special boxes or running on existing network management nodes. For end-user applications, e.g. streaming media, network measurement tools can be embedded into the main application. Doing this, measurements can be performed using the main application traffic instead of special measurement traffic. Also, the main application could receive direct feedback from the measurements, allowing for proactive adjustment of the application traffic. Relevance for industry and society The Internet infrastructure is based on a best-effort connectionless service. A major drawback is that providing an enhanced network service, e.g., with guaranteed bandwidth or delay, is difficult. This fact is hampering growth, because traditional telecom business models are typically based on hard guarantees, guarantees that cannot be made in the current Internet. This is especially problematic to independent service providers with no control over the infrastructure. Hence, while the current Internet design (best-effort, push of functionality towards the network edges) stimulates and facilitates innovation of new services, the same design makes it difficult to generate revenue from those services. One way to deal with these difficulties is to move towards models where reliance on reserved resources is replaced by reliance on measurement of available resources, to which service can be adapted and differentiated. There is thus a need for applications and tools that accurately measure network behavior. The network operators need such tools to run their networks efficiently and to be able to control the offered services. End users need such tools to get better and more predictable end-to-end performance of e.g. streaming media. In the network arena, there are basically four kinds of players: network owners, network operators, service providers and users. Each of these players can benefit from performance measurement tools and applications. The gains are in terms of increased efficiency (cost saving) and enabling of new services. From the perspective of growth, both these aspects are important even though the latter provides more clearly identifiable growth. From the perspective of innovation, altogether new types of services can emerge. The results of the BARTAP project are applications and tools for network performance measurement. The project results enables better knowledge about traffic situations and therefore enable improved competition between operators, new opportunities for value-added services, and more efficient network operations. In the following, we will briefly describe these three effects and explain how they lead to growth. Increased efficiency: More efficient operation of a network means that more traffic can be handled with the same resources, which leads to a cheaper service attracting more customers, but also enabling more bandwidth-hungry application services. Both effects lead to growth. Improved competition: Tools measuring actual network performance delivered by an operator provide essential information to a customer for assessing the `value for money' given by that operator. The result is a better functioning competition between the operators. Better competition leads to growth. New business opportunities: A key component of a business model is typically service differentiation where better services are charged higher prices than simpler services. We have identified three opportunities for new business which depend on performance measurement methods provided by the project:

3 1: Enhanced network services, meaning services with a specified quality-of-service, but not with hard guarantees. 2: Probabilistic end-to-end network QoS, relying only on measurements, statistics and possibly redundancy to provide quality of service. 3: Virtual operators, reselling or trading bandwidth. These three new opportunities not only create new business, but also increase network traffic. Both lead to growth. Goals and results The overall goal of BARTAP is to provide applications and implementations of network measurement tools. Goals from section 5 of the call that project BARTAP addresses: Short term: Increased utilization of results from previous EU projects. Results from the EU FP6 project Evergrow are directly utilized in BARTAP. Medium term: Successful demo projects in areas of industrial importance. BARTAP will produce demo- and prototype implementations that are of direct industrial importance. Increased cooperation between IT- and telecom industry, research institutes and academia. In BARTAP, researchers from the IT- and telecom industry, research institutes and academia will cooperate closely. Increased industrial knowledge through new patents and standards. BARTAP builds on results from the EvaluNet project. In EvaluNet, an international patent application was submitted. Results from BARTAP will be subject for patent application. Increased mobility of personnel between academia and industry. As a results of the EvaluNet project, two researchers from MdH moved to industry (Ericsson). This is likely to happen again in BARTAP. Increased academic competence through degrees and publications. The plan in BARTAP is to produce two licentiate degrees and at least two high-quality publications per year. Long term: Project results are actively used by industry. The BARTAP partner Ericsson plans to actively use the results from BARTAP. Increased participation in EU frame programs. All partners in BARTAP will be active in the approved EU FP7 project MOMENT starting in Increased growth and competitiveness though new possibilities for new actors. Better bandwidth management will allow for sustainable growth. Measurement-based QoS is a potential for new actors such as bandwidth brokers and virtual network operators. Relation to ongoing or planned EU and other international projects The BARTAP project complements the EU FP7 project MOMENT mentioned above. MOMENT is approved and will start The main goal of MOMENT is to build an open, unified infrastructure

4 where results from measurements and monitoring activities can be saved and shared. Complementing MOMENT, BARTAP focuses on applications and implementations of measurement techniques. Results from MOMENT can be utilized by applications developed in BARTAP. BARTAP applications can be used to produce input to the MOMENT infrastructure. BARTAP applications can also be used and evaluated within the Celtic project TRAMMS (Traffic Measurements and Models in Multi-Service networks). The main goal of the TRAMMS project is to describe the behavior of end-users in fixed broadband networks, to characterise the traffic that they generate, and to use this knowledge in creating dimensioning rules for capacity planning. A basis for the project and a particular strength of the consortium is the access to fixed access networks/test beds with real end-uses from which genuine traffic data can be extracted. State-of-the-art and proposed project qualities In recent years, there has been considerable interest in the ability to measure network capacity (and the unused portion thereof; the available capacity) as well as other important network characteristics. Broadly, there are three categories of measurement techniques: active, passive and monitor-based. Active techniques, also known as probing techniques, inject special probe flows into the network and then make inferences based on how those flows are affected by the network (e.g. Jain/Dovrolis, Melander/Björkman, Pasztor/Veitch, Ribeiro). For passive techniques, the inferences are instead based on observations of existing traffic flows (e.g. Lai/Baker, Paxson). The third category, monitor-based measurements, is related to passive techniques, but instead of observing existing flows, the inferences are based on statistics collected by routers (e.g. Anjali, Netflow). These statistics are based on the traffic flows that traverse the routers and include information such as number of forwarded packets (or bytes) and number of dropped packets. Another way of categorizing measurement techniques is by the metric that is measured; hop-by-hop (e.g. Pathchar, Tailgater) or end-to-end (e.g. Pathload, TOPP, Pathchirp). The hop-by-hop methods try to measure some property, e.g. the link capacity or the available bandwidth, of every link of a network path. The end-to-end methods instead try to measure similar properties over an entire path, e.g. the available bandwidth of an end-to-end network path. Today, the most active research groups in the area of active methods for bandwidth measurement besides our own group are Dovrolis et al at Georgia Tech, Ribeiro et al at Rice University, and Darryl Veitch's group at University of Melbourne. There has been an increasing interest in doing traffic characterization, both as part of network operation and traffic engineering, but also as a basis for better understanding and better modeling of traffic behavior. Several research groups are active in this area. Among the most prominent are CAIDA, AT&T Lab-Research and Sprint Labs. CAIDA is a collaborative undertaking among organizations from the commercial, government, and research sectors. Its primary focus is on the development of measurement, analysis, and visualization tools. Researchers at Sprint Labs have within the IPMON project built up an extensive measurement infrastructure and they are, based on the measurement results, doing leading work on traffic matrix estimation as well as characterization, modelling and long-term forecasting of Internet backbone traffic. AT&T Labs-Research is doing important work in several network research areas. Most relevant for this project is their work on network measurements, traffic variability and traffic matrix estimation. In Sweden, the most active in the bandwidth measurement area are MdH (BARTAP applicant Prof. Mats Björkman's group), SICS (BARTAP co-applicant Assoc.Prof. Martin Nilsson, plus the CNA group under Dr. Bengt Ahlgren), Ericsson (BARTAP co-applicant Dr. Andreas Johnsson's group, plus Dr. Svante Ekelin s group) and BTH (Prof. Arne Nilsson and Dr. Adrian Popescu). The consortium around BARTAP thus collects most of the Swedish competence in the measurement area. As described above, members of the BARTAP consortium are active in the foremost research front. TOPP and BART are two measurement and analysis methods developed by BARTAP members. The TOPP method was absolutely unique when it was first published, it has since been copied by others. Our most recent method BART, a method that is central to BARTAP, has advanced state-of-the-art in the measurement area considerably.

5 Measures of success Three important measures of the success of BARTAP will be: On the academic side, the number of citations of our publications of results from BARTAP gives an important indication of the academic success of the research conducted in BARTAP. On the industrial side, the number of licensed users of our methods and applications gives an important indication of the industrial interest in the results from the BARTAP project. On the user community side, the number of non-commercial applications of our methods and tools is a strong indicator of the general usefulness of the BARTAP results. Work plan Research strategy and method The BARTAP project will focus around development and implementation of applications and tools for network performance measurements. A large part of the project will therefore have an emphasis on software development and implementation. The BARTAP project will use the BART bandwidth measurement method, developed within the EvaluNet project. Within BARTAP, one-way delay, jitter and packet loss are also important network characteristics. The BART method will therefore be augmented to incorporate these characteristics. Here we will follow a traditional development method with theoretical analysis, test implementation and verification of the algorithms developed. The BARTAP project will have two parallel activities, network management tools and end user applications, respectively. To a large extent, the two activities will be jointly staffed, thus allowing for joint development of central measurement features common to the two activities. Project partners and related internal projects The consortium around BARTAP consists of Mälardalens högskola, Ericsson AB and SICS AB. As interested but passive receiver of information functions.se (former Stiftelsen för Internetinfrastruktur). Mälardalens högskola (MdH) participates with personnel from the research group COMPASS, lead by Professor Mats Björkman. Professor Björkman and two PhD students will be active in the BARTAP project. Project BARTAP relates to activites at MdH where network performance is studied and predicted. Ericsson AB participates with personnel from Ericsson Research. Dr. Andreas Johnsson will lead Ericsson AB's participation in the BARTAP project. Ericsson AB is interested in applying results from BARTAP in the project Robust networking, where light-weight QoS is studied with IPTV as one important application. Ericsson AB is also interested in using results from BARTAP for producing network characteristics maps. Assoc. Prof. Martin Nilsson will lead SICS AB's participation in the BARTAP project. He will also lead the implementations work package in the EU FP7 STREP project MOMENT starting in 2008, where a unified infrastructure for network performance measurements is developed. BARTAP will also be able to benefit from SICS' role as the Center for Networked Systems (CNS) institute excellence center..se is a receiver of information from the BARTAP project..se is interested in BART applications, and plans to use BART applications for available bandwidth measurements in the Swedish parts of the Internet.

6 Project plan The BARTAP project consists of two parallel activities; (1) development and implementation of a tool for network management, and (2) development and implementation of an end user application incorporating BART. Network management activity To actively and effectively manage a network, several metrics such as one-way delay, jitter, packet loss rate and node availability are important to measure. We believe that end-to-end available bandwidth, which is estimated by BART, is an important complement to describe the characteristics and current status of a network. The aim of the network management activity part of BARTAP is to develop an infrastructure of network nodes (e.g. boxes) running BART, and other measurement methods as well, for estimating the above mentioned metrics. The nodes can be placed at different locations in a heterogeneous network, consisting of wireline and wireless links. Estimation of the end-to-end available bandwidth between these nodes will then be used as the underlying data for creating a network map depicting its current characteristics but also to track in real time how these characteristics evolve over time. Another aspect of network management using BART measurement infrastructure is to create tools for deploying the information obtained from the network characteristic maps, in different applications. The accuracy of the network map created using BART will be evaluated and validated in testbed settings where all parameters can passively be monitored. The results from such evaluations will be used as input for refinement of the design on the measurement infrastructure. End-user application activity A simple instance of a streaming media application contains one sender and one receiver. The application's task is to vary the sending bandwidth depending on available bandwidth in such a way that the receiver receives a smooth stream of data. The basic design of the end-user application contains a module which receives bandwidth data and recommends a suitable transmission rate to the application. The first step in the activity is to select a streaming application where this can be done in an as simple and modular way as possible. Then, this is implemented and evaluated. The process is iterated, so that the evaluation result is fed back to the design stage, suggesting methodological improvements. We consider this feedback an essential part of the project, and expect at least two iterations of the development cycle. Time table Each of the two activities (1) network management tools and (2) end user applications will have three distinct phases; (a) design, (b) implementation and (c) evaluation/validation. The two activities will be staggered in time since activity (1) will feed its initial results to activity (2). Below, a time line is presented that show the two action lines through the project duration. Two cycle iterations are assumed. Activity 1a Activity 1b Activity 1c Activity 1a Activity 1b Activity 1c Activity 2a Actitivy 2b Activity 2c Activity 2a Actitivy 2b Act:y 2c Month