Conquering video: overcoming the congestion conundrum

Telecoms.com periodically invites third parties to share their views on the industry’s most pressing issues. In this piece Raffaele D’Albenzio, Solution Architect at F5 Networks, looks at ways CSPs can counter the challenges posed by increased video consumption in a cost-effective way.

Video is fast emerging as the Holy Grail for mobile operators and the numbers don’t lie. Facebook users consume eight billion videos a day and 82% of those active on Twitter view video content. Significantly, 90% of Twitter video views and 60% of YouTube views are now from users on mobile devices.

The video bonanza is partly fuelled across the industry by ambitious service providers offering zero rating approaches or aggressively priced unlimited data plans. For example, mobile network Three announced in July plans to include unlimited video streaming for free as part of some contracts. This has been further complicated by ethical debates about the management of network traffic by major operators, as regulators seek to uphold net neutrality. In this context, intelligent traffic management is key for mobile network operators adapting to a landscape with no scope to relax customer service standards.

The majority of mobile video has two main characteristics: encryption via SSL (or similar protocols) and the fact that it is based on Adaptive Bit Rate (ABR) technology, which changes video resolution depending on available bandwidth. Although encryption is a key security feature, it can hinder the ability of operators to maintain a high-quality user experience, as the encryption protocols used by video providers such as Netflix and YouTube can prevent data optimisation using standard traffic management tools. To counter the challenges posed by increased video consumption in a cost-effective way, service providers must look to improve the way Transmission Control Protocol (TCP) works on the mobile network.

TCP is the key transport protocol of internet infrastructure; the glue which, together with Internet Protocol (IP), ensures that all applications connect smoothly to our devices. It allows us to share resources with billions of people all over the world at the same time. It also establishes and manages traffic connections and congestion while taking care of transmission errors.

Today, the ability to detect video streams and manage them using TCP-Proxy-based bandwidth controls or Shaping Capabilities for User Datagram Protocol-based video streams can have a profound impact. It enables service providers to adapt and reduce the amount of bandwidth used by video streams, while continually safeguarding the user experience. Looking ahead, TCP optimisation will become increasingly important to service providers by significantly improving download performance by signal strength on faraway networks

Furthermore, TCP optimisation also allows mobile operators access to radio-centric congestion control algorithms, that adapt to the idiosyncrasies of specific networks. These algorithms are vital conduits to improve traffic flow and the overall user experience. Techniques such as these can also decrease the time between client and TCP termination, enabling both sides to react quickly in the instance of isolated losses or congestion events in the network. Furthermore, it is possible to decrease retransmissions to improve radio resource efficiency.

TCP has many moving parts, with new ones being added every day. Making sense of it all without proper fine-tuning is ill-advised. It is crucial for decision-makers to choose a TCP stack that encompasses high goodput and minimal buffer bloat, as well as allowing for fairness between flows. In the era of mass video dissemination and usage, the TCP must be more than a static bolt-on. Integration with other functionalities — including deep packet inspection, traffic steering, and load balancing — is essential.

Raffaele D’Albenzio is a Solution Architect at F5 Networks. He specialises in IP networking and network security, with over 15 years of experience in the enterprise tech and service provider markets.