Network Virtualization: The OSI Model’s Future
These days, it seems like everyone has their own opinions on networks and network stacking frameworks.
In fact, some experts are on the verge of abandoning the layering concept altogether in favour of a fully integrated stack where forwarding, transport, session management, and everything else are just one big layer, or at best, abstract layers that only the controller needs to worry about. This is due to the rise of software-defined networking (SDN) and network functions virtualization (NFV).
The Open Systems Interconnection (OSI) concept, which has been there since the internet originally converged on the TCP/IP stack back in the 1990s, is in the middle of all of this.
Throwing out the old
But is it appropriate to demand a whole new network architecture merely because network virtualization is displacing conventional physical networks?
And given that contemporary methods only need three, four, or none at all, is there still a reason to comprehend the idea of a seven-layer network architecture?
Russ White, a writer and network specialist, raised some questions last autumn when he plainly said, “The OSI Model does not correctly explain networks.”
Although this could be the case, it’s fair to claim that neither TCP/IP nor the existing SDN or NFV concepts do. It is just a question of perspective to claim that OSI is incorrect because it separates processes like presentation and session management into separate layers rather than include them in transport or networking since network stacking is simply conceptual in the first place.
White continued by stating that OSI was created to transfer the principles that underpinned circuit switching to more modern packet-switched networks (PSN). While this made it possible to overlay packet networks on top of circuit networks, it was cumbersome and largely unneeded with the development of middleboxes that took on individual hosts’ packet-switching duties.
He concludes by saying that although OSI may be helpful when developing apps, it’s not all that wonderful for creating real networks.
Ivan Pepelnjak, a network architect, told IP Space attendees to hold on.
OSI is much more than just a straightforward layering paradigm. It works just as well as an implementation of the network stack, such as LCC on Ethernet or CLNP on a network layer, as it does as a functional framework. You may handle different network processes in a logical, predictable manner by organising them into attractive, ordered views.
In this way, even if the actual design deviates from the OSI framework strictly on paper, it still helps to illustrate how networks operate.
Sadly, he said, OSI has developed into something of a religion over time as network students were questioned about the different levels and what they performed without being informed that this was simply one possible way to perceive networks, not the only possible one.
We are now living in the SND/NFV age, where the controller takes care of everything and human operators simply need to worry about what data they want to transfer where.
Application, control, and infrastructure are the sole layers in SND, while virtual networking, management/orchestration, and infrastructure are the three functionalities described in NFV (MANO).
But once again, both of these frameworks include the fundamental processes outlined in the OSI, although in different words and framed inside various levels and roles.
So, it’s safe to state that neither SDN nor NFV lessen the requirement for OSI nor did TCP/IP. To make networking simpler and more responsive to the demands of contemporary users and applications, it instead incorporates OSI (including TCP/IP) under a new management and orchestration paradigm.
The conventional methods of networking were restrictive and time-consuming, as Total Uptime recently noted. A lot of mapping, coding, and even debugging were necessary for modifications, which were then fixed on the networking until fresh changes were required.
All of it is virtualized using SDN and NFV, and administration is directed through a centralised controller.
Operators may just tell the controller what they need instead of having to manage every device on the network, and the controller will route each packet along the most effective route to its destination.
Although they are not stacked in the same manner, functions relating to apps, sessions, presentations, and even the physical network, are still present.
The easiest way to think about OSI, TCP/IP, and all other network frameworks is to compare them to a house’s blueprints. Every home has a foundation, walls, roof, wiring, heat, and similar components, yet various structures will employ these components in different ways.
Even though subsequent innovations like slate roofs and drywall have gained popularity, the original layout, which featured timber walls and a thatched roof, still serves as a helpful model for what a basic home should look like.
Every network performs the same fundamental task: moving data from one location to another.
The route to knowing how networks are today and how they might be improved in the future is made easier with an awareness of how networks were envisioned in the past.