Tim Cahall is CEO of Manticom Networks, a developer of Ethernet switching and transport technology. A former executive with Trellis Photonics and Lucent Technologies, he shared ideas on VOD provisioning.
Q: In a point-to-point VOD solution, you’ve said that most MSOs wind up installing up to five times the amount of network they need. What are they unnecessarily installing? What are their alternatives?
Cahall: VOD is a service that is fundamentally different than services currently being offered by MSOs over their HFC networks since it is a ‘one-to-one’ service. This means that there is a single video stream being dedicated to a single customer. With the introduction of gigabit Ethernet as a new means of transport and the replacement of the legacy digital video broadcast (DVB) asynchronous serial interface (ASI) transport technology, a major improvement has been achieved.
However, most current Ethernet implementations (Layer 1, or "point-to-point") actually lead to an under-utilization of the MSO’s network assets. The MSO ends up implementing an "over-capacity" of transport equipment as much as X times. From a technical standpoint, Layer 2 or higher solutions fulfill the criteria to match the dynamics of this bandwidth-on-demand service but are simply not cost effective to support the VOD business case of an MSO.
Q: You’ve also called VOD a ‘lumpy’ service. Will you explain that, and discuss how spreading Ethernet switches across the geography of the network can help?
Cahall: What I mean by that is that you really can’t predict what the usage is going to be. There’s no way to predetermine how many streams you’re going to need at any given time, at any given location. As we have seen with other opt-in services, such as NVOD, consumer behavior varies widely by location, time of day, demographics and the content being offered.
I do think that you will continue to see lumpiness but I do think the delta between the peak and the average usage, which is currently very large, will shrink.
Q: Manticom’s platform, which scales from 2.5 Gbps to 20 Gbps, can push VOD economics below $35 per-provisioned subscriber. How did you arrive at those numbers, and are they ‘real-world’?
Cahall: As a starting point, we used the common metric in the industry in order to calculate the transport of bandwidth from the video server to the hub. Manticom’s solution is competitive with any Layer 1 solution. However, Layer 1 Ethernet is a point-to-point solution. As you don’t know in which hub the next request for VOD will occur, you’re forced to over-provision your network. Therefore, we introduced a new metric, the cost-per- provisioned subscriber.
When you bring the over-provisioning factor into the equation, the cost increases significantly for Layer 1 solutions. With Layer 2 solutions, over-provisioning is not necessary. From Day One, we set a benchmark for ourselves to provide Layer 2 functionality at Layer 1 pricing. When you add the over-provisioning effect to a real-world network, the difference between our solution and our competitors becomes substantial.