Recursive Internetwork Architecture: Difference between revisions

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RINA is the result of an effort that tries to work out the general principles in [[computer networking]] that applies to everything. RINA is the specific architecture, implementation, testing platform and ultimately deployment of the theory. This theory is informally known as the Inter-Process Communication “IPC model” <ref>John Day, Ibrahim Matta and Karim Mattar. Networking is IPC: A guiding principle to a better Internet. In Proceedings of the 2008 ACM CoNEXT Conference. ACM, 2008</ref> although it also deals with concepts and results that are generic for any distributed application and not just for networking.

The IPC model captures the common elements of distributed applications, called DAFs (Distributed Application Facilities) or DAFs, as illustrated in the Figure to the right. A DAF is composed byof two or more Distributed Application Processes or DAPs, which collaborate to perform a task. These DAPs communicate using a single application protocol called CDAP (Common Distributed Application Protocol) or CDAP, which enables two DAPs to exchange structured data in the form of objects. All of the DAP’s externally visible information is represented by objects and structured in a Resource Information Base (or RIB), which provides a naming schema and a logical organization to the objects known by the DAP (for example a naming tree). CDAP allows the DAPs to perform six remote operations on the peer’s objects (create, delete, read, write, start and stop).

In order to exchange information, DAPs need an underlying facility that provides communication services to them. This facility is another DAF whose task is to provide and manage Inter Process Communication services over a certain scope, ; hence this DAFand is called DIF:a Distributed IPC Facility -or theDIF. A DIF can be thought of as a layer., A DIFand enables a DAP to allocate flows to one or more DAPs, by just providing the names of the targeted DAPs and the characteristics required for the flow (bounds on data loss and delay, in-order delivery of data, reliability, etc.). DAPs may not trust the DIF they are using, therefore may decide to protect their data before writing it to the flow - for example using encryption - via the SDU (Service Data Unit) Protection module.

[[File:RINA-arch.png|thumb|350px|Figure 3. Example of RINA networks and IPC Process components]]

DIFs, being DAFs, can also be the users of other underlying DIFs, creating in this way the recursive structure of the RINA architecture. The DAPs that are members of a DIF are called IPC Processes or IPCPs. They have the same generic DAP structure shown in Figure 2, plus some specific tasks to provide and manage IPC. These tasks, as shown in Figure 3, can be divided into three categories: data transfer, data transfer control and layer management. The elements are ordered in increasing complexity and frequency of use, with elements at the far left being used the most (per packet processing) but the least complex, and elements to the right being not often used, but very complex. All the layers provide the same functions and have the same structure and components, however these components are configured via policies in order to adapt to different operating environments.

As depicted in Figure 2 RINA networks are usually structured in DIFs of increasing scope, starting from the so-called lower layers and going up closer to the applications. A provider network can be formed by a hierarchy of DIFs multiplexing and aggregating traffic from upper layers into the provider’s backbone. None of the provider internal layers need to be externally visible. Multi-provider DIFs (such as the public Internet or others) float on top of the [[ISP]] layers. Only three types of systems are required: hosts (which contain applications), interior routers (systems that are internal to a layer) and border routers (systems at the edges of a layer, which go one layer up or down).

In short, RINA has the following features:

* It builds on a very basic premise, yet fresh perspective that networking is not a layered set of different functions but rather a single layer of distributed Inter-Process Communication (IPC) that repeats over different scopes. Each instance of this repeating IPC layer implements the same functions/mechanisms but policies are tuned to operate over different ranges of the performance space (e.g. capacity, delay, loss).