General8.10.2012

Why use a local CDN?

You wouldn’t use an oil tanker to transport a few gallons of oil to a local garage…. no, you would use a courier – or even a panel van. In the same breath there are sometimes occasions where companies should rather opt for a local content delivery network (CDN), as opposed to a global CDN, to distribute content across local/regional networks and private WANs.

Otherwise it could be a case of “serious over-kill”, said Jacek Dziembowski, a director of Antfarm – one of the country’s leading video streaming providers – and the first company to design and operate it’s own streaming media content delivery network (CDN).

Dziembowski said that while local, South African CDNs are “scarce”, South African companies are advised against expecting international CDNs to transport content efficiently to South African based Internet users. “Striking an analogy,” he said, “it is often a case of companies using a transatlantic oil tanker to transport what could be transported by a local airline such as Kulula or a local courier such as DHL– far faster, more efficiently, and less expensive.”

He said there are a few global CDN providers operating in the country. “However, while these companies offer good technology and services, one must be careful of making use of an international solution when a local solution – which is naturally much better suited to local requirements – would be a far better option from an efficiency, reliability and price/performance point of view.”

A CDN is a network solution designed specifically to address the challenges of serving content across bandwidth constrained network topologies e.g. Internetworks, private & public WANs. “It must be remembered,” said Dziembowski, “that ‘Internetworks’ have bottlenecks. They are, by design, inefficient at transporting high bandwidth or large volumes of content. Bottlenecks can occur at locations of high traffic concentration – such as long distance backhaul links or ISP peering points. “This is where a CDN comes into play. It can act to overcome bottlenecks by distributing content to the Internetwork edge or by offloading and diverting traffic from congested locations within a network.” Dziembowski said a CDN can offer a number of benefits, such as the ability to create faster response times (lower latency), reduced connection time, reduced buffering (streamed media) – as well as being able to distribute a higher quality of content.

“A CDN – which is essentially a large distributed system of caches or media servers deployed in multiple data centres on the Internet – is engineered to serve content to end users with high availability and performance such as file-based media, on-demand & live streaming audio / video and multimedia content. Today,” he said, “CDNs serve a large proportion of the Internet content – although this is not a well known fact.”

A CDN operator and provider– such as Antfarm – gets paid by content providers such as media companies for delivering their content to their audience of end users. In return for this service, the CDN provider users ISPs, carriers and network operators for hosting its infrastructure in their data centers and/or purchasing of network capacity.

“Besides providing better performance and availability, CDNs also offload the traffic served directly from the content provider’s origin infrastructure, resulting in costs savings for the content provider. It must be remembered that as the amount of information being disseminated around the globe continues to grow, bottleneck problems are going to increase as networks just cannot cope with the volumes involved – and this is where CDNs are required. They alleviate the pressures of disseminating this growing mass of information and data. They are becoming vital in the increasingly cyber world – and this is unlikely to change.

“But,” said Dziembowski, “it is important for folks needing a CDN not to get carried away. While it might seem like an alluring idea to make use of a global CDN, remember that if you are a local company – with local content delivery requirements – you might be better served to look to a local CDN provider, and to harness the regionally appropriate capabilities of a local CDN. Otherwise you could end up paying for a Hummer when a Suzuki would suffice…

“End users need to assess what kind of CDN they really require – not what some company tries to sell them. They need to decide whether or not a local CDN supplier will suffice. There might not be a lot of local CDNs on offer right now – but they are available…”

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