Machine Learning Authors: Liz McMillan, Yeshim Deniz, Pat Romanski, William Schmarzo, Jason Bloomberg

Blog Feed Post

TCP Congestion Control: The Mobile Network of Today, It’s Time to Improve

Over the last several years the rise of the smartphone has led to substantially increased capabilities in mobile devices. The emergence of applications for these platforms has enabled a near limitless number of ways for consumers and enterprise users to interact with people, systems and businesses. Supporting much more than telephony, today’s phones function as a primary source of Internet and application access.

Why Is the Mobile Experience So Important?
A poor end-user experience on a mobile device can be devastating to a business. For example, a video stream that is pixilated, choppy or interrupted midstream can rapidly spiral from an annoying end-user experience to a highly frustrating one, resulting in lost potential repeat visits, and potential revenue. Even in the presence of ample bandwidth a mobile device’s inability to process and render video frames, or to correctly synchronize audio with video, can still leave the end user dissatisfied.

What is TCP Congestion Control?
TCP congestion control uses a number of mechanisms to achieve high performance and avoid congestion collapse, where network performance can fall by several orders of magnitude. These mechanisms control the rate of data entering the network, keeping the data flow below a rate that would trigger collapse, resulting in a poor end-user experience.

The Legacy Approach: Packet Loss = Congestion
Legacy congestion control algorithms used packet loss metrics to determine when to limit the congestion window or send rate. High speed is a loss based algorithm which continues to increase the send rate and congestion until it perceives packet loss.  Once this occurs, it knows to slow down, and cuts the window in half. 

The Evolution of Congestion Control: 3G vs. 4G LTE
Modern mobile traffic is harder to control. With 4G LTE networks, packet loss does not necessarily mean there is congestion on the networks, and vice-versa, congestion does not necessarily mean that there is packet loss.  This realization means that congestion control algorithms cannot focus on packet loss and latency alone for determining congestion.

  3G 4G
Latency 100-500 ms 50ms
Peak Rate 384 Kbps 150 Mbps
Typical User Rate 200 Kbps 10-20 Mbps
Buffer size Small Large
Behavior High packet loss Low packet loss

Bandwidth Estimation
The next generation of congestion control algorithms is based on bandwidth estimations.  These algorithms change send rates depending on the bandwidth at the time of packet loss, and can adaptively set send rates based on the bandwidth.  TCP Westwood is a bandwidth based algorithm, and provides higher throughput and better fairness of bandwidth over wireless links compared to TCP Reno.  However, these algorithms do not perform well with smaller buffers which may not have a large range of bandwidths to work with. 

From Throughput to “Goodput
Finally, the latest type of congestion control algorithm is latency based. This means they determine how to change the send rate by analyzing changes in round trip time(RTT).  This type of algorithm is a way of preventing congestion before it begins, thus minimizing queuing delay at the cost of “goodput”.  Goodput focuses on the application-level throughput. TCP Vegas is a latency based algorithm to determine how the network is performing.  If the base RTT estimation is too low the network will not be optimally used. If it is too big, TCP Vegas may overload the network. 

The Best of Both Worlds
Leveraging the F5 Synthesis architectural vision, we are excited to announce our BIG-IP v11.5  release, and our own TCP Woodside as part of The New TCP Express. The F5 hybrid solution that looks at both packet loss and delay.   Queuing delay is calculated based on the difference between the base delay and max delay.   If loss is determined to be a result of delay and not congestion the CC algorithm will not kick in and reduce the rate of packets. However, when the queuing delay is minimal, it will rapidly accelerate to maximize the use of the available bandwidth and moderate loss based congestion control.  As a result downloads are improved by up to 30%, while addressing the different characteristics of 3G, 4G LTE, and Wi-Fi networks.



A big thank you to my coworkers Crystal Bong and Danny Luedke for their help in writing this blog post. 

Read the original blog entry...

More Stories By Dawn Parzych

Dawn Parzych is a Technical Product Marketing Manager at Instart Logic. Dawn has had a passion for web performance for over 15 years with a focus on how to make the web faster. As a technical product marketing manager at Instart Logic, she researches and writes about trends in the web performance space and how they impact the user experience. Prior to joining Instart Logic, Dawn worked at F5 Networks, Gomez & Empirix.

@CloudExpo Stories
Dion Hinchcliffe is an internationally recognized digital expert, bestselling book author, frequent keynote speaker, analyst, futurist, and transformation expert based in Washington, DC. He is currently Chief Strategy Officer at the industry-leading digital strategy and online community solutions firm, 7Summits.
"We started a Master of Science in business analytics - that's the hot topic. We serve the business community around San Francisco so we educate the working professionals and this is where they all want to be," explained Judy Lee, Associate Professor and Department Chair at Golden Gate University, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
DXWorldEXPO LLC announced today that Dez Blanchfield joined the faculty of CloudEXPO's "10-Year Anniversary Event" which will take place on November 11-13, 2018 in New York City. Dez is a strategic leader in business and digital transformation with 25 years of experience in the IT and telecommunications industries developing strategies and implementing business initiatives. He has a breadth of expertise spanning technologies such as cloud computing, big data and analytics, cognitive computing, m...
Digital Transformation and Disruption, Amazon Style - What You Can Learn. Chris Kocher is a co-founder of Grey Heron, a management and strategic marketing consulting firm. He has 25+ years in both strategic and hands-on operating experience helping executives and investors build revenues and shareholder value. He has consulted with over 130 companies on innovating with new business models, product strategies and monetization. Chris has held management positions at HP and Symantec in addition to ...
Cloud-enabled transformation has evolved from cost saving measure to business innovation strategy -- one that combines the cloud with cognitive capabilities to drive market disruption. Learn how you can achieve the insight and agility you need to gain a competitive advantage. Industry-acclaimed CTO and cloud expert, Shankar Kalyana presents. Only the most exceptional IBMers are appointed with the rare distinction of IBM Fellow, the highest technical honor in the company. Shankar has also receive...
There is a huge demand for responsive, real-time mobile and web experiences, but current architectural patterns do not easily accommodate applications that respond to events in real time. Common solutions using message queues or HTTP long-polling quickly lead to resiliency, scalability and development velocity challenges. In his session at 21st Cloud Expo, Ryland Degnan, a Senior Software Engineer on the Netflix Edge Platform team, will discuss how by leveraging a reactive stream-based protocol,...
DXWorldEXPO LLC announced today that Kevin Jackson joined the faculty of CloudEXPO's "10-Year Anniversary Event" which will take place on November 11-13, 2018 in New York City. Kevin L. Jackson is a globally recognized cloud computing expert and Founder/Author of the award winning "Cloud Musings" blog. Mr. Jackson has also been recognized as a "Top 100 Cybersecurity Influencer and Brand" by Onalytica (2015), a Huffington Post "Top 100 Cloud Computing Experts on Twitter" (2013) and a "Top 50 C...
Enterprises have taken advantage of IoT to achieve important revenue and cost advantages. What is less apparent is how incumbent enterprises operating at scale have, following success with IoT, built analytic, operations management and software development capabilities - ranging from autonomous vehicles to manageable robotics installations. They have embraced these capabilities as if they were Silicon Valley startups.
Daniel Jones is CTO of EngineerBetter, helping enterprises deliver value faster. Previously he was an IT consultant, indie video games developer, head of web development in the finance sector, and an award-winning martial artist. Continuous Delivery makes it possible to exploit findings of cognitive psychology and neuroscience to increase the productivity and happiness of our teams.
The standardization of container runtimes and images has sparked the creation of an almost overwhelming number of new open source projects that build on and otherwise work with these specifications. Of course, there's Kubernetes, which orchestrates and manages collections of containers. It was one of the first and best-known examples of projects that make containers truly useful for production use. However, more recently, the container ecosystem has truly exploded. A service mesh like Istio addr...
Predicting the future has never been more challenging - not because of the lack of data but because of the flood of ungoverned and risk laden information. Microsoft states that 2.5 exabytes of data are created every day. Expectations and reliance on data are being pushed to the limits, as demands around hybrid options continue to grow.
Poor data quality and analytics drive down business value. In fact, Gartner estimated that the average financial impact of poor data quality on organizations is $9.7 million per year. But bad data is much more than a cost center. By eroding trust in information, analytics and the business decisions based on these, it is a serious impediment to digital transformation.
Business professionals no longer wonder if they'll migrate to the cloud; it's now a matter of when. The cloud environment has proved to be a major force in transitioning to an agile business model that enables quick decisions and fast implementation that solidify customer relationships. And when the cloud is combined with the power of cognitive computing, it drives innovation and transformation that achieves astounding competitive advantage.
Digital Transformation: Preparing Cloud & IoT Security for the Age of Artificial Intelligence. As automation and artificial intelligence (AI) power solution development and delivery, many businesses need to build backend cloud capabilities. Well-poised organizations, marketing smart devices with AI and BlockChain capabilities prepare to refine compliance and regulatory capabilities in 2018. Volumes of health, financial, technical and privacy data, along with tightening compliance requirements by...
"NetApp is known as a data management leader but we do a lot more than just data management on-prem with the data centers of our customers. We're also big in the hybrid cloud," explained Wes Talbert, Principal Architect at NetApp, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life settlement products to hedge funds and investment banks. After, he co-founded a revenue cycle management company where he learned about Bitcoin and eventually Ethereal. Andrew's role at ConsenSys Enterprise is a mul...
Evan Kirstel is an internationally recognized thought leader and social media influencer in IoT (#1 in 2017), Cloud, Data Security (2016), Health Tech (#9 in 2017), Digital Health (#6 in 2016), B2B Marketing (#5 in 2015), AI, Smart Home, Digital (2017), IIoT (#1 in 2017) and Telecom/Wireless/5G. His connections are a "Who's Who" in these technologies, He is in the top 10 most mentioned/re-tweeted by CMOs and CIOs (2016) and have been recently named 5th most influential B2B marketeer in the US. H...
The best way to leverage your Cloud Expo presence as a sponsor and exhibitor is to plan your news announcements around our events. The press covering Cloud Expo and @ThingsExpo will have access to these releases and will amplify your news announcements. More than two dozen Cloud companies either set deals at our shows or have announced their mergers and acquisitions at Cloud Expo. Product announcements during our show provide your company with the most reach through our targeted audiences.
DevOpsSummit New York 2018, colocated with CloudEXPO | DXWorldEXPO New York 2018 will be held November 11-13, 2018, in New York City. Digital Transformation (DX) is a major focus with the introduction of DXWorldEXPO within the program. Successful transformation requires a laser focus on being data-driven and on using all the tools available that enable transformation if they plan to survive over the long term. A total of 88% of Fortune 500 companies from a generation ago are now out of bus...
With 10 simultaneous tracks, keynotes, general sessions and targeted breakout classes, @CloudEXPO and DXWorldEXPO are two of the most important technology events of the year. Since its launch over eight years ago, @CloudEXPO and DXWorldEXPO have presented a rock star faculty as well as showcased hundreds of sponsors and exhibitors! In this blog post, we provide 7 tips on how, as part of our world-class faculty, you can deliver one of the most popular sessions at our events. But before reading...