QoS Irrational Rationing

For readers who want me to be more controversial, here is a dismissive epistle to a few industries (see my video blog entry here for more).

 

Let’s start at the beginning: What are we trying to manage?

 

You will notice that from our hourglass model, the levels below seven are managing Internet technologies, but in most cases, solutions that address QoS know little about the application.

 

Many well-intentioned engineers have advocated solutions such as deep packet inspection for the purpose of placing a priority tag on the quality of service needed. QoS on the Internet can be accomplished by adding bandwidth. With enough bandwidth routing, the Internet becomes uniform and works predictably.

 

(The above is adapted from Wikipedia.)

 

At the core of the Internet backbone, the 100 ms delay is being maintained. So the issues of QoS are normally within a specific service provider or application provider and the connections between them. More often than not, it’s a problem somewhere between the access network and regional network to network interconnections and not the hand-off to the Internet backbones.

 

QoS does not manage bandwidth but what to do when there is scarcity. This is why many network planners say that QoS is about “rationing the inadequate,” which means it is doomed to fail.

 

However, the issues are not as straightforward because your access to the Internet can be supported by a variety of techniques that bring your device deeper into the routing of the Internet – or bring the application closer to your device.

 

Access is often managed at the second layer, while the applications are often cached in the cloud to provide a more timely response. Since the advent of the commercial Internet, the network is no longer about an “any-to-any” meet point on the Internet (I used to be all about the NAPs). The story now is about the content delivery sites and hosted services.

 

 

(Source: Craig Labowitz at nanog)

 

In the last few years, more than half of the major Internet sites migrated to 150 Content Delivery Networks.

 

As the wireless broadband comes of age the QoS questions we should expect these few CDNs become a strategic partners or competitor to the ILECs. This is why Google’s Android has some unique properties: It represents not only a phone and navigation technique, but a CDN that supports carrier partners.

 

In the meantime, on your device, the network provider you choose will have methods of providing some form of quality, either by compression, computing or caching. None of these impact QoS transport but all of them impact your experience.

 

As we move to 4G, this balance – between the device experience versus the network QoS – is going to become more pronounced to the network operators, but less to the subscriber. “It just works” will be the view of the subscriber.