Der Artikel beschreibt am praktischen Beispiel, wie eine DMR-Netzwerkarchitektur inhärente Herausforderungen bei der Content-Zuführung über IP meistert.
Content providers are increasingly looking at the internet as a video distribution medium, but this alternative to satellite is only practical if the internet’s inherent limitations can be overcome.
The architecture of the internet fundamentally restricts its use for content delivery to multiple destinations. Built as a unicast system, the internet fundamentally lacks any native ability to send the same packet from one source to multiple destinations. Thus, to send a single video feed to multiple destinations over the internet, the source location must send multiple copies of the same content – one copy for each destination. When the number of destinations grows beyond just a few, this approach quickly becomes impractical. Additionally, because the internet is a ‘best efforts’ medium, lost packets need to be recovered once detected which for video means delays of multiple seconds must be added in order to allow for this recovery.
Through the application of unique “overlay” technology and the development of a managed network of data centers using LTN-developed and patented technology, LTN Global has overcome both fundamental challenges – i.e. latency and unicast – presented by the internet’s underlying architecture.
Bringing Exacting SLA Metrics to Internet Video Delivery LTN has built a global backbone of interconnected datacenters around its patented technologies, which include rapid error recovery (RER) and dynamic multi- carrier routing (DMR) algorithms. This architecture has established a fully managed video transport service over the internet with extraordinarily high reliability. The resulting network, exceeds 99.999 % availability with < 200 milliseconds latency so LTN can guarantee performance that matches and frequently exceeds those of
either satellite or fiber. The company can offer IP-based transmission which is not only a cost-effective alternative to those other delivery mechanisms, it is also much more flexible. LTN’s network, unlike satellite, allows for different content to be distributed to certain destinations if desired – think local advertising or localized content.
Dynamic Multi-Carrier Routing Network Architecture Within the LTN model, client appliances connect to LTN data centers and each data center has access to multiple Tier 1 carrier networks. As the upper web of elements in Figure 1 illustrates, traffic can flow between clients and data centers or between data centers over multiple carrier paths.
Using multiple carrier backbones (Tier 1 ISPs’ core IP networks), LTN’s DMR network architecture ensures high-availability end-to-end connectivity. Informed by real-time monitoring, backbone servers use near-instantaneous messaging and patented rapid routing algorithms to switch traffic between these different carrier planes (shown in green, blue, and red in Figure 1) – every few milliseconds if necessary – to take advantage of the best internet link and to ensure unimpeded arrival of the traffic flows. This therefore avoids the issues caused by the congestion, delay or sudden unavailability that regularly occur on the internet which unchecked cause “drop-outs” in the video flows.