@inproceedings {25278,
	title = {Alternative Backoff: Achieving Low Latency and High Throughput with ECN and AQM},
	journal = {IFIP Networking},
	year = {2017},
	note = {Best Paper Award},
	publisher = {IFIP},
	abstract = {A number of recently proposed Active Queue Management (AQM) mechanisms instantiate shallow buffers with burst tolerance to minimise the time that packets spend enqueued at a bottleneck. However, shallow buffering causes noticeable TCP performance degradation as a path{\textquoteright}s underlying round trip time (RTT) heads above typical intra-country levels. Using less-aggressive multiplicative backoffs in TCP can compensate for shallow bottleneck buffering. AQM mechanisms may either drop packets or mark them using Explicit Congestion Notification (ECN), depending on whether the sender marked packets as ECN-capable. While a drop may therefore stem from any type of queue, an ECN-mark indicates that an AQM mechanism has done its job, and therefore the queue is likely to be shallow. We propose ABE: {\textquotedblleft}Alternative Backoff with ECN{\textquotedblright}, which consists of enabling ECN and letting individual TCP senders back off less aggressively in reaction to ECN-marks from AQM-enabled bottlenecks. Using controlled testbed experiments with standard NewReno and CUBIC flows, we show significant performance gains in lightly-multiplexed scenarios, without losing the delay-reduction benefits of deploying AQM. ABE is a sender-side-only modification that can be deployed across networks incrementally (requiring no flag-day) and offers a compelling reason to deploy and enable ECN across the Internet.},
	keywords = {AQM, congestion control, ECN, low latency, tcp},
	url = {http://dl.ifip.org/db/conf/networking/networking2017/1570335770.pdf},
	author = {Khademi, Naeem and Armitage, Grenville and Welzl, Michael and Zander, Sebastian and Fairhurst, Gorry and Ros, David}
}
@article {25372,
	title = {NEAT: A Platform- and Protocol-Independent Internet Transport API},
	journal = {IEEE Communications Magazine},
	volume = {55},
	year = {2017},
	month = {06/2017},
	pages = {46-54},
	publisher = {IEEE},
	abstract = {The sockets Applications Programming Interface (API) has become the standard way that applications access the transport services offered by the Internet Protocol stack. This paper presents NEAT, a user-space library that can provide an alternate transport API. NEAT allows applications to request the service they need using a new design that is agnostic to the specific choice of transport protocol underneath. This not only allows applications to take advantage of common protocol machinery, but also eases introduction of new network mechanisms and transport protocols. The paper describes the components of the NEAT library and illustrates the important benefits that can be gained from this new approach. NEAT is a software platform for developing advanced network applications that was designed in accordance with the standardization efforts on Transport Services (TAPS) in the Internet Engineering Task Force (IETF), but its features exceed the envisioned functionality of a TAPS system.},
	issn = {0163-6804},
	doi = {https://doi.org/10.1109/MCOM.2017.1601052},
	author = {Khademi, Naeem and Ros, David and Welzl, Michael and Bozakov, Zdravko and Brunstr{\"o}m, Anna and Fairhurst, Gorry and Grinnemo, Karl-Johan and David Andrew {Hayes} and Hurtig, Per and Jones, Tom and Mangiante, Simone and T{\"u}xen, Michael and Weinrank, Felix}
}
@inproceedings { ANRW2017,
	title = {A NEAT Way to Browse the Web},
	journal = {Proceedings of the Applied Networking Research Workshop~(ANRW)},
	year = {2017},
	note = {Demo Presentation},
	month = {07/15/2017},
	publisher = {IEEE},
	address = {Praha/Czech Republic},
	abstract = {There is a growing concern that the Internet transport layer has become ossified in the face of emerging novel applications, and that further evolution has become very difficult. The NEAT system is a novel and evolvable transport system that decouples applications from the underlying transport layer and network services. In so doing, it facilitates dynamic transport selection. This demo shows how the NEAT system is able to dynamically select the most appropriate transport solution for the Mozilla Firefox web browser.},
	keywords = {NEAT, ossification, SCTP, tcp, Transport Selection, Transport Service},
	url = {https://irtf.org/anrw/2017/anrw17-final13.pdf},
	author = {Weinrank, Felix and Grinnemo, Karl-Johan and Bozakov, Zdravko and Brunstr{\"o}m, Anna and Dreibholz, Thomas and Hurtig, Per and Khademi, Naeem},
	editor = {T{\"u}xen, Michael}
}
@article {24987,
	title = {Operating ranges, tunability and performance of CoDel and PIE},
	journal = {Computer Communications},
	volume = {103},
	year = {2017},
	month = {05/2017},
	pages = {74-82},
	publisher = {Elsevier},
	abstract = {Bufferbloat is excessive delay due to the accumulation of packets in a router\&rsquo;s oversized queues. CoDel and PIE are two recent Active Queue Management (AQM) algorithms that have been proposed to address bufferbloat by reducing the queuing delay while trying to maintain a high bottleneck utilization. This paper fills a gap by outlining what are the operating ranges, that is the network characteristics (in terms of round-trip times and bottleneck capacity), for which these algorithms achieve their design goals. This new approach to the problem lets us identify deployment scenarios where both AQM schemes result in poor performance when used with default parameters. Because PIE and CoDel have been proposed with RED\&rsquo;s deployment issues in mind, it was essential to evaluate to what extent we can tune them to achieve various trade-offs and let them control the queuing delay outside their default operating range. We find that, by appropriate tuning (1) the amount of buffering can easily be controlled with PIE, (2) the Round Trip Time (RTT) sensitivity of CoDel can be reduced. Also, we observe there is more correlation between the congestion level, the achieved queuing delay and the targeted delay with CoDel than with PIE. This paper therefore concludes there is no single overall best AQM scheme, as each scheme proposes a specific trade-off.},
	keywords = {AQM, Bufferbloat, CoDel, congestion control, PIE},
	doi = {http://dx.doi.org/10.1016/j.comcom.2016.07.013},
	author = {Kuhn, Nicolas and Ros, David and Amadou Baba {Bagayoko} and Kulatunga, Chamil and Fairhurst, Gorry and Khademi, Naeem}
}
@techreport {aqm-eval-draft,
	title = {AQM Characterization Guidelines},
	year = {2016},
	month = {07/2016},
	publisher = {IETF},
	abstract = {Unmanaged large buffers in today\&$\#$39;s networks have given rise to a slew\&nbsp;of performance issues. \&nbsp;These performance issues can be addressed by\&nbsp;some form of Active Queue Management (AQM) mechanism, optionally in\&nbsp;combination with a packet scheduling scheme such as fair queuing.\&nbsp;The IETF Active Queue Management and Packet Scheduling working group\&nbsp;was formed to standardize AQM schemes that are robust, easily\&nbsp;implementable, and successfully deployable in today\&$\#$39;s networks. \&nbsp;This\&nbsp;document describes various criteria for performing precautionary\&nbsp;characterizations of AQM proposals. \&nbsp;This document also helps in\&nbsp;ascertaining whether any given AQM proposal should be taken up for\&nbsp;standardization by the AQM WG.},
	keywords = {Active Queue Management},
	issn = {2070-1721},
	url = {https://tools.ietf.org/html/rfc7928},
	author = {Kuhn, Nicolas and Natarajan, Preethi and Khademi, Naeem and Ros, David}
}
@inproceedings {24988,
	title = {On the Cost of Using Happy Eyeballs for Transport Protocol Selection},
	journal = {Applied Networking Research Workshop (ANRW)},
	year = {2016},
	month = {07/2016},
	pages = {45-51},
	publisher = {ACM},
	abstract = {Concerns have been raised in the past several years that introducing new transport protocols on the Internet has become increasingly difficult, not least because there is no agreed-upon way for a source end host to find out if a transport protocol is supported all the way to a destination peer. A solution to a similar problem\&mdash;finding out support for IPv6\&mdash;has been proposed and is currently being deployed: the Happy Eyeballs (HE) mechanism. HE has also been proposed as an efficient way for an application to select an appropriate transport protocol. Still, there are few, if any, performance evaluations of transport HE. This paper demonstrates that transport HE could indeed be a feasible solution to the transport support problem. The paper evaluates HE between TCP and SCTP using TLS encrypted and unencrypted traffic, and shows that although there is indeed a cost in terms of CPU load to introduce HE, the cost is relatively small, especially in comparison with the cost of using TLS encryption. Moreover, our results suggest that HE has a marginal impact on memory usage. Finally, by introducing caching of previous connection attempts, the additional cost of transport HE could be significantly reduced.},
	keywords = {CPU load, Happy Eyeballs, memory usage, SCTP, tcp, TLS, Transport-protocol selection},
	isbn = {978-1-4503-4443-2},
	doi = {https://doi.org/10.1145/2959424.2959437},
	url = {https://irtf.org/anrw/2016/anrw16-final27.pdf},
	author = {Papastergiou, Georgios and Grinnemo, Karl-Johan and Brunstr{\"o}m, Anna and Ros, David and T{\"u}xen, Michael and Khademi, Naeem and Hurtig, Per}
}
@article {24989,
	title = {De-ossifying the Internet transport layer: A survey and future perspectives},
	journal = {IEEE Communications Surveys and Tutorials},
	year = {2016},
	month = {11/2016},
	publisher = {IEEE},
	abstract = {It is widely recognized that the Internet transport layer has become ossified, where further evolution has become hard or even impossible. This is a direct consequence of the ubiquitous deployment of middleboxes that hamper the deployment of new transports, aggravated further by the limited flexibility of the Application Programming Interface (API) typically presented to applications. To tackle this problem, a wide range of solutions have been proposed in the literature, each aiming to address a particular aspect. Yet, no single proposal has emerged that is able to enable evolution of the transport layer. In this work, after an overview of the main issues and reasons for transport-layer ossification, we survey proposed solutions and discuss their potential and limitations. The survey is divided into five parts, each covering a set of point solutions for a different facet of the problem space: 1) designing middleboxproof transports, 2) signaling for facilitating middlebox traversal, 3) enhancing the API between the applications and the transport layer, 4) discovering and exploiting end-to-end capabilities, and 5) enabling user-space protocol stacks. Based on this analysis, we then identify further development needs towards an overall solution. We argue that the development of a comprehensive transport layer framework, able to facilitate the integration and cooperation of specialized solutions in an application-independent and flexible way, is a necessary step toward making the Internet transport architecture truly evolvable. To this end, we identify the requirements for such a framework and provide insights for its development.},
	keywords = {API, middleboxes, protocol-stack ossification, transport protocols, user-space networking stacks},
	issn = {1553-877X},
	doi = {https://doi.org/10.1109/COMST.2016.2626780},
	author = {Papastergiou, Georgios and Fairhurst, Gorry and Ros, David and Brunstr{\"o}m, Anna and Grinnemo, Karl-Johan and Hurtig, Per and Khademi, Naeem and T{\"u}xen, Michael and Welzl, Michael and Damjanovic, Dragana and Mangiante, Simone}
}
@techreport {abe-caia-2015,
	title = {Alternative Backoff: Achieving Low Latency and High Throughput with ECN and AQM},
	year = {2015},
	month = {07/2015},
	publisher = {Centre for Advanced Internet Architectures (CAIA), Swinburne University of Technology},
	address = {Melbourne, Australia},
	abstract = {CoDel and PIE are recently proposed Active Queue Management (AQM) mechanisms that minimize the time packets spend enqueued at a bottleneck, instantiating shallow, 5 ms to 20 ms buffers with short-term packet burst tolerance. However, shallow buffering causes noticeable TCP performance degradation when a path{\textquoteright}s underlying round trip time (RTT) heads above 60ms to 80ms (not uncommon with cross-continental and inter-continental traffic). Using less-aggressive multiplicative backoffs is known to compensate for shallow bottleneck buffering. We propose ABE: {\textquotedblleft}Alternative Backoff with ECN{\textquotedblright}, which consists of enabling Explicit Congestion Notification (ECN) and letting individual TCP senders use a larger multiplica- tive decrease factor in reaction to ECN-marks from AQM- enabled bottlenecks. Using a mix of experiments, theory and simulations with standard NewReno and CUBIC flows, we show significant performance gains in lightly- multiplexed scenarios, without losing the delay-reduction benefits of deploying CoDel or PIE. ABE is a sender- side-only modification that can be deployed incrementally (requiring no flag-day) and offers a compelling reason to deploy and enable ECN across the Internet.},
	url = {http://caia.swin.edu.au/reports/150710A/CAIA-TR-150710A.pdf},
	author = {Khademi, Naeem and Welzl, Michael and Armitage, Grenville and Kulatunga, Chamil and Ros, David and Fairhurst, Gorry and Gjessing, Stein and Zander, Sebastian}
}
@inproceedings {aqm-eval-gi-symposium,
	title = {The New AQM Kids on the Block: An Experimental Evaluation of CoDel and PIE},
	journal = {17th IEEE Global Internet Symposium},
	year = {2014},
	month = {04/2014},
	publisher = {IEEE},
	address = {Toronto},
	abstract = {Active Queue Management (AQM) design has again come into the spotlight of network operators, vendors and OS developers. This reflects the growing concern and sensitivity about the end-to-end latency perceived by today{\textquoteright}s Internet users. CoDel and PIE are two AQM mechanisms that have recently been presented and discussed in the IRTF and the IETF as solutions for keeping latency low. To the best of our knowledge, they have so far only been evaluated or compared against each other using default parameter settings, which naturally presents a rather limited view of their operational range. We set thus to perform a broader experimental evaluation using real-world implementations in a wired testbed. We have in addition compared them with a decade-old variant of RED called Adaptive RED, which shares with CoDel and PIE the goal of {\textquoteleft}{\textquoteleft}knob-free{\textquoteright}{\textquoteright} operation. Surprisingly, in several instances results were favorable towards Adaptive RED.
},
	doi = {http://dx.doi.org/10.1109/INFCOMW.2014.6849173},
	author = {Khademi, Naeem and Ros, David and Welzl, Michael}
}
