In a world where the focus is on mobile and the digital experience, it’s hard to believe that we still have a need for anything that doesn’t follow this model. As conversations continue to center on web-scale networking, why do we still have demand for web-scale networking? It turns out, there are a few key technical reasons these dinosaurs are hanging on.
A recent blog post by Ciena dives in a little deeper, taking a look at the insights of the company’s Packet Networking expert, John Hawkins. One of those dinosaurs, it seems, is Time Division Multiplexing, or TDM. According to Hawkins, it doesn’t seem to be going anywhere quickly. It seems more than a few of us like to hold onto the way companies of all sizes have managed the distribution of voice for years.
For its part, TDM services rely on a time-based method to multiplex services over a media like copper to carve up the available capacity into time-slots dedicated to specific customer services. Such services we tend to know as T1/E1, T3/E3 and SDH/SONET. The challenge with this approach is that TDM tends to be a relatively inflexible solution as it can’t scale or flex with the variable demand that tends to exist in the enterprise.
Still, even with these limitations, TDM tends to be useful today. End-users in industries like transportation, utilities, mobile operators and others rely on certain characteristics of TDM services. For instance, it still sets the standard for reliability and was engineered to deliver quality at this higher standard. It’s also why so many view VoIP as an inferior connection option as it hasn’t always performed to the same standard. TDM services can be protected and have the ability to react to failure in mere milliseconds, thereby protecting the end-user’s application.
Another perk available with TDM is the accurate timing information that tends to be inherent in the system. In order for the system to work, the time slots have to be precisely timed. As such, the end-user application can borrow the clocking provided by the TDM system. This capability is great for the utility, for instance, that needs to support power relay activation or the cell site that needs precise timing for call handoff.
With a growing focus on the development of web-scale networking projects, will we continue to see the decline of TDM? We might, in industries where the precise characteristics of the TDM system don’t make sense. For others, however, that precise approach to the way information is transferred still holds value. Until there is a replacement that maintains that higher standard, TDM is here to stay.
Edited by Maurice Nagle