When customers talk about increasing bandwidth or having access to big pipes, the general theory behind it is that of Jeremy Clarkson. More! More speed, more power, more of all that is good. The reality is actually quite different, but big pipes are a politicians dream.
In reality, a larger link is only good in one respect and that is in handling congestion at a very basic level. When we consider the concept of a road, it has a speed limit – a limitation that is enforced. So the question becomes how many lanes are there? With a single carriageway, there is one path in and one path out. With a dual carriageway, there are two paths each way and so on. So, if we transpose this to the concept of a network, increasing the link size is really just widening the road. Yes, you can get more traffic through, but only up until the carriageways are fully being used.
Now, in this politically correct world, let’s take a look at the example of a foreign national driving on Australian roads for the first time. The rules in their country may be different. The etiquette is most likely different. For example, in my parents home country of Sri-Lanka, pressing the horn means, “Look out, I am about to overtake you, so move over to the left, I have given you fair warning.” It could also mean, “There is about to be an accident, use your eyes!” Or it could mean, what the horn is actually there for, “I am here!”
In the networking world, an application that should have the horn on all times is Voice. This is an important application group and is one that users feel pain quickly if the traffic is not handled correctly. With the concept of a big pipe, there is no fair queuing, so the traffic is handled on a first come, first serve basis. This leads to all sorts of problems even on the biggest links at times of high utilization. Aha, yes Zen, that is just it, a bigger link will reduce peak periods of activity. Well, yes, it will reduce it based on the current throughput of traffic, however, as the traffic increases, the utilization will increase as well. We have seen this happen everywhere regardless of the size of the link. It is the same as the speed of the link. The link is analogous to a bank account you give to an average teenager. If they realize that they have cash, their behaviour will change and will generally head down the path of spending it.
I remember moving from dial-up to cable. I literally went from 64kbps to 30Mbps. It was a huge difference. However, as time has gone on, the content becomes richer, more devices come onto the network, the bandwidth is now a lot more utilized than ever and the ability to prioritize and control traffic as well as understand what traffic is consuming the link has become even more relevant, particularly with a wireless network, there are no end of brute force attacks to try and join to get free Wi-Fi.
So, at best, a bigger pipe is a short term deference to the bigger issues which are that content has changed and will continue to do so, the richer the content, the higher the consumption and also, people are people and will take what they can get in accordance with what they are wanting to do.
I’ve got a big pipe! But, for how long my friend?