The Bones of Contention

Tuesday, December 2 2014


To the sound of popping corks and effervescing champagne, I’m proud to announce that I’ve just added a whopping 12 meters of optical fiber to the global Internet. OK, so that only equates to a miniscule 0.000113272% of the 10594km Paris – Singapore SWM3 cable system but for what could be described as a fairly well connected household (the last time I looked, there were 25 active devices in the MAC address table of our router) this is a seminal moment.

Or is it?

Contention ratios have always been part of PSTNs. In the past, if everyone tried to use their fixed line telephone at once, the system would overload and you’d get a busy tone. This principle still holds true in the hyper-connected age, albeit in a somewhat different and more complex way.

The fact is that your 1Mb/s of Internet access (or 1Gb/s if you are lucky) isn’t necessarily yours, at least not all of the time. And it doesn’t stop there – in reality you are most likely sharing your Mb/s with up to twenty or fifty (if you are less lucky) other subscribers on your provider’s network – just to get access to the equipment that takes your valuable packets to the cyberspace launch pad.

Once it is on its way, your valuable traffic may well have to negotiate its way through further bottlenecks across any number of upstream IP transit, peer networks and interconnection points en route to its final destination. At every transition point you will be sharing available network bandwidth with more people and contention becomes a truly global affair.purple-contention

This is why a good Internet experience isn’t really so much about who provides your access services but equally, if not more so about the networks that supply upstream connectivity to your local access provider.

At the end of the day, there are a number of questions that are equally as important as the number of zeroes at the end of your access bandwidth figure:

  • How much available capacity does your provider have to its own upstream networks?
  • What do these upstream networks look like?
  • How quickly can hot-spots be alleviated?
  • How short are the paths to critical internet content?
  • Is there any backup when things go wrong?

With SDN and NFV in the toolbox, there are bound to be profound changes to established concepts of contention on the way. As technology reduces upgrade times from weeks to seconds, networks will be better positioned to manage available bandwidth more effectively and scale-up exactly as and when the need arises.

One thing is certain though, contention these days is no longer just a local concern and it’s fair to say that in this context at least, less really is more.