In the Cloud Era, the WAN is Abstracted

If you have been in the connectivity business long enough, you know that terminology changes over time. Our definitions of “broadband” are a moving target. Functions are virtualized, so appliances no longer dictate operations. And networks are evaluated differently by infrastructure suppliers and customers of those networks. 

Consider the term middle mile. In traditional parlance, we did not use the term. Traditionally, the portion of the network between Class 4 switches was the wide area network. The part of the network connecting a Class 5 switch with customers was the local access network (local loop). That meant the network connecting Class 5 switches with Class 4 switches was the “distribution” network, which might have been viewed as the “middle mile” between the access and wide area networks. 

For internet access providers, “middle mile” means something altogether different, and has less to do with transport function or distance. For an internet service provider, the middle mile is that function moving traffic from an ISP’s own signal processing location (headend, central office, data center) to the nearest internet point of presence. 

source: TeleGeography 

It is a functional requirement and a cost element that assumes the cloud and wide area networks exist, but abstracts them. 

For an ISP or enterprise, “WAN” is an abstraction. Actual costs are determined by the cost of interconnecting at an internet point of presence. Transport is simply a function that is provided by the interconnection cost. 

In a retail commerce setting, looking at logistics, “middle mile” means the movement of goods from a supplier warehouse to a retailer location. And that is a fairly good analogy. 

From an ISP or enterprise perspective, WAN no longer is a direct cost element, as once was the case for T-1 or DS3 wide area connections. What matters is the cost of connecting the ISP access traffic to the nearest internet point of presence. 

As with “cloud” architecture, the WAN is abstracted. What matters is the cost of connecting at an internet point of presence.