The Internet started as a way to communicate electronically, but has grown into something that is now the foundation of nearly every business. In the early 1990s when e-mail was just starting to catch on in enterprises, no one imagined that two decades later we would be making purchases and watching full-length movies on our Smartphones. This change in content and the burgeoning of Internet devices have stressed communications networks worldwide. None more so than the edge of the data center network, where the delivery of the content starts.
Below is a simple high-level diagram of the Internet network. There are three distinct network types within the end-to-end network – core (backbone), metro, and access. The core is the part that connects Internet Service Providers (ISPs) facilities to each other via peering points or Network Access Points (NAPs) as well as long distances between cities. The metro typically connects ISP’s points-of-presences (PoP) together within a particular metropolitan area. Though now, there are many ISPs that share equipment within PoPs. Access networks connect homes, enterprises and cell towers to the ISP. The data center network edge is the portion that connects to the applications and hosts – so edge routers that communicate with PCs, Internet servers, wireless laptops, Smartphones, etc. within the access network of communications service providers (CSPs) and enterprises – where the data is stored.
Figure 1: Internet Network Diagram (Source: http://navigators.com)
While this diagram describes the network for an ISP, it could just as easily represent the traditional telecom network, and in fact, it is important to remember that some of the first ISPs were traditional telecom and cable TV providers like AT&T and Time Warner. Therein lies one of the issues with the legacy installations – they were built for voice and analog TV, not for data. And even today, in the age of broadband Internet access, the actual networks transporting the data have not been fully upgraded. The original peering points or network access points (NAPs) have been augmented by some private peering points, but most of these are still in the same urban areas and still running some of the same legacy equipment.
Time-domain multiplexing (TDM) and Synchronous Optical Networking (SONET) ports on large telecommunications routers have largely handled the Internet network edge for many years. This is slowly transitioning to Optical Transport Network (OTN) ports, but not very quickly mainly because of cost. One of the issues with the data center network edge is that what is used to connect to the Internet is dependent on what type of business needs access and what service providers have available in their area. For example, a large enterprise based in a metropolitan area probably has more than one fiber connection running multiple wavelengths, while a small/medium sized business (SMB), even within that same metropolitan area is still connected with copper. Both of these types of companies have data centers, but they most likely look drastically different.
Content distribution is compounding the issue of outdated networks. Most Internet content providers like Google, Facebook, Netflix and the like, only have a handful of data centers throughout the world so accessing the information quickly can be challenging. These companies have elicited the help of content distribution network (CDN) providers like Akamai to improve the situation, but this is not enough.
For companies running their own networks to support their business operations, content delivery can be even more perplexing. And with new smart mobile devices being introduced every day, the problem is only getting worse. Wireless tablets, fitness monitors, Smartwatches, Smarthome automation, video streaming and the like are already reality, but in some cases not very useful yet because of bandwidth issues at the data center edge.
Another concern with content distribution is that even the few newer data centers that exist are typically near larger cities near overstrained Internet peering points. When they were built, this made sense because they were only supporting applications like e-mail, blogs, searches and news that are intermittent streams of data. Now, with the ever-increasing user expectation of having a high-quality data connection in order to turn-on a home-security system from anywhere in the world on-the-fly, navigate around high-volume traffic using on-demand GPS or stream video on a long car-trip, the installed content delivery network is overburdened and slow.
The solution to the bottleneck is to get the content closer to the end user – many smaller peering points (data centers) closer to the local access. This would eliminate delay from congested core networks and large Internet exchanges. More on CDN and data center companies that are addressing these issues will be discussed in subsequent posts.