Protocol & Layers

OSI Model

The Open Source Interconnection (OSI) Model amends a client in host to inter- communicate with a comparing component at a similar layer in another host. The model gives usefulness to (N) layer & (N-1) layers, where N is one of the seven layers of protocols working. Layer N software on the destination computer must receive the exact message sent by layer N software on the sending computer.

Data processing by two conveying OSI-compatible gadgets continues as follows :

1. The data to be transmitted is formed at the topmost layer of the transmitting device (layer N) into a protocol data unit (PDU) and gets passed to layer N-1 as service data unit (SDU).

2. With a header, a footer, or both, SDU now moves to layer N-2.

3. The process proceeds until reaching the lowermost level, from which the data gets transmitted to the receiving device.

4. Vice versa happens, the data is passed from the lowest to the highest layer on the receiving device.

5. As a progression of SDUs while being successively stripped from each layer’s header or footer until reaching the topmost layer, where the remainder data is expended.

Researchers deliberately developed the OSI model to support Client-Server architecture over the Internet. However, OSI fizzled at gaining widespread acceptance; the present Internet uses the TCP/IP model. Be that as it may, for P2P decentralized WWW, it is critical to guarantee security and tamper-proof at each stage the data passes through; so, the equivalent can be applied to P2P architecture as well.

However, there is no expectation to rehash an already solved problem. By including missing necessary protocols functions in layers, and removing some OSI is re-engineered to fortify a new interoperable peer network, having each layer in the protocol stack provides a specific function. These protocols offer types of assistance to the layer directly above. Besides, each layer communicates to its peer layer in the system to which it is related.

Layers

The architecture of ByNodes is coherently separated into layers building up the entire structure: a service layer, a DAG-chain layer, and a network layer. Each layer offers support for the layer above to accomplish the necessities of ByNodes.

The service layer focuses on how to support specific evidence-related services by using the DAG-chain. In this layer, multiple signature schemes get employed to ensure integrity, verifiability, privacy, and other necessary characteristics. To satisfy the scalability requirements and simplify the design, ByNodes adopts a loose coupling structure with two modules, a storage module (Trinabl), and a DAG- chain module (Zoe), to separate evidence storage and management. The storage module gets used to support evidence storage, and the DAG-chain module participates in evidence collection, verification, and retrieval.

The DAG-chain layer is responsible for constructing a Zoe chain for each node in the underlying network. The network environment is relatively safe, and block mining does not rely on an economic incentive. Thus, ByNodes can adopt a private or consortium network. This helps in distributing block bodies to different nodes. The main challenge in this layer is the DLT chain bloat. To overcome these challenges, we propose a mixed DLT rather than a full DAG-chain through Zoe.

The network layer is used to construct the network topology and support communication. Most blockchain schemes use the Peer-to-peer (P2P) network as the blockchain network. ByNodes also adopts a new P2P interface through Zeno to organize nodes and provides scalable P2P routing (Neith) and encryption communication to support the specific tasks for other layers layers, for example, broad- cast transactions, the encrypted transmission of evidence information, maintain the consensus of the DAG-chain.