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1 November 2022

Nokia returns to content delivery networks with low-latency offering

September 2018 signalled a sea-change for the video industry, when Nokia joined Cisco and Ericsson in exiting the IP video marketplace following the sale of assets to Volaris Group – which then formed a new content distribution network (CDN) business, Velocix.

Four years passed and now two Nokia senior product managers, Keith Chow and Kenneth Wan, are talking about the firm making world-first video streaming breakthroughs with a live CDN product claiming to be more profitable for providers than anything else on the market.

Seemingly out of nowhere, the Nokia CDN for Live technology has arrived to address both over-the-top and IPTV markets under one single hardware and software platform. Cost-effectively addressing live streaming latency challenges has been core to the proposition.

A demo showed the Nokia Live CDN delivering a soccer stream at a whole five seconds ahead of a well-known betting company, in the data stream. The same soccer demo showed the Nokia product streaming at a significant 60 seconds ahead of a global live sport OTT service provider’s stream, and even 45 seconds ahead of an operator OTT platform which is delivered using a “state-of-the-art” CDN.

Being a live CDN, latency is paramount. An accompanying graph plots the Nokia Live CDN at an average of 9 seconds glass-to-glass live latency – which Nokia boasts is comparable to latency of DTT and digital satellite/cable TV.

Nokia’s extensive experience in IPTV and multicast is the main ingredient, which has evolved with a simple software upgrade to support both OTT and IPTV. Nokia CDN for Live comes with both multicast and routed unicast support – picking up contribution feeds from MPEG broadcast streams, and wrapping them up using optimized Real-time Transport Protocol (RTP) for IP transmission, delivered for optimal conditions.

The problem with traditional live OTT video delivery, according to Nokia, is that it relies too heavily on the TCP protocol. The technology is fine for file segment transfer with high efficacy, but has fundamental disadvantages for live streaming, including severe latency, caused by multiple buffer points (distributed CDN and end device), plus limited fast channel change and frequent buffering, leading to poor video quality and experience.

The biggest disadvantage of all with using traditional CDNs, as Nokia sees it, are the high annual recurring costs, accumulating from processing-intensive tasks and unnecessary memory for video caching.

However, Nokia knows that RTP over User Datagram Protocol (UDP) is not without its downsides, as TCP benefits from effective packet retransmission. Nokia therefore took the best thing about TCP and added it to RTP over UDP. This enables Nokia CDN for Live to send packets as fast as possible, and because every packet has a unique sequence number, in the event of packet loss, it is possible for the end device to request any missing packets. Retransmission and redundancy are therefore taken care of – effectively moving the latency problem from TCP.

“Our CDN always sends video through unicast – so you don’t have to necessarily run multicast in your network, the technology can provide always-on unicast to address OTT too,” commented Wan.

Nokia’s technology is trying to manipulate packets in a way we haven’t seen before – likely because tens of patents are protecting Nokia CDN for Live, which we are told has one of the highest patents per line of code of any platform out there.

“Not many can do this. Someone tried to copy it and infringed a few patents, but it was taken down by the local authorities,” said Chow.

At the heart of Nokia CDN for Live are Nokia’s 7750 service routers – with millions of devices deployed worldwide, mostly at tier 1 and 2 operators. Many European CSPs already have thousands of Nokia SRs in the network edge that can be turned on with the flip of a switch – ranging from few hundred meters to a few thousand meters from most homes.

Service routers are good at packet forwarding and packet replication, in multicast or unicast depending on the network arrangement. All channel requests go via Nokia 7750 SRs, although if a customer is using a third-party retransmission server, this is compatible, but with the caveat of limited fast channel change.

Nokia wants to help heavyweight operators bring live OTT and IPTV delivery inhouse to reduce annual recurring costs to ashes. The barrier to entry is notably high, but the hope is that Tier 1s and 2s have enough in-house experience working with multicast that switching to Nokia CDN for Live should be a walk in the park. For live delivery, Nokia has hopes of disrupting traditional CDNs, but not VoD. For now, the onus is on live delivery, primarily because people pay lots of money for live sports events, which is proven by the growth in Nokia’s IP video.