Akamai tweaks UDP for OTT streaming, Vimeo embraces it

We have written a lot about CDN giant Akamai’s focus on UDP (User Datagram Protocol) multicast technologies to tackle last mile issues between the edge server and viewer, where delivery is out of the firm’s usually capable hands. This week, Akamai has expanded on this with the launch of Media Acceleration, a product specifically geared towards improving the viewing experiences of OTT video viewers and internet gamers.

Akamai’s strategy here is in line with the trend that delivery of content over the internet will shift to using fixed bit rate methods which are more reliable than ABR. The development of UDP multicast technologies has enabled Akamai to switch traffic in the network core and this supposedly puts less strain on its servers, and can run better in the local network.

Bandwidth hungry video formats such as 4K and VR are increasingly contributing to this problem of stretching CDN providers’ servers to the max, and UDP multicast, along with cloud and performance management tools, aims to relieve an element of mounting pressure. UDP multicast is also particularly useful for cellular, in which the network behavior is more predictable.

Akamai claims Media Acceleration will bring a broadcast-like quality of service to broadband delivery, using quick UDP internet connections (QUIC) framework, an emerging standard, to deliver secure transmissions over UDP, combined with Akamai’s congestion control tools. Akamai is slotting Media Acceleration into its Adaptive Media Delivery and Download Delivery product portfolio, available to customers at no additional cost.

UDP multicast has attracted the attention of AT&T for live events in its OTT system development, as one notable example. It isn’t clear if AT&T, or any other tier 1 operators for that matter, has tested this at scale yet, but anything Akamai puts out must scale into millions of instances unchanged.

The technology behind Media Acceleration looks familiarly like that from UDP multicast innovator Octoshape, the Danish company Akamai acquired back in April 2015.

A very similar announcement was made by Akamai this time last year, in the run up to NAB, so Media Acceleration looks to us like Akamai has made some tweaks to its existing technologies, rather than launched an entirely new product. Akamai has also developed its own UDP multicast services in the past, so perhaps it is slightly unfair to attribute 100% of the technology to Octoshape.

The Octoshape technology, as it was before being snapped up by Akamai, first encapsulates video in a UDP wrapper, and then sends the video onto a cloud server in multiple FEC (forward error correction) protected copies, and the client draws from more than one of these copies, taking several routes over the internet. The system decides which copies to take which parts of the content from, minimizing the FEC calculations it needs to do at the client, then unwraps the UDP stream and turns it back into ABR format to play.

Octoshape simply spins up cloud instances in Rack space or any other cloud service and bounces the content off these to any part of the world without using expensive CDN caches.

The streams get across the internet from the servers in a number of ways, it can come directly as a UDP stream, it can use a relatively new IETF (internet engineering task force) protocol called Automatic Multicast Tunneling, which allows a UDP stream to tunnel across parts of the best effort internet, or it can go via a single multicast enabled router.

Vimeo has been testing Media Acceleration since December 2016 and Akamai reports that the video sharing site “realized immediate improvements in its viewer experiences” – claiming it saw a notable increase in requests for HD quality playbacks once it switched traffic.

Vimeo’s VP of Engineering, Naren Venkataraman, commented: “with video creators comprising such a large portion of our customer base, delivering high quality video and the experience to match is of utmost importance to maintaining the Vimeo brand.”

Akamai VP of Product Management, Scott Brown, said: “traditional television distribution has fundamental commercial and operational characteristics that are very different from internet video distribution today. Akamai has developed Media Acceleration to function as a vehicle through which we can introduce innovations that address the quality and scale challenges of OTT, while also facilitating sustainable economic models that can help enable the growth of video distribution over the internet.”