## Networkign layer research

### Trivia

Polkadot-sdk (formely called substrate) is widely used as a framework for distributed networks, including blockchain, distributed computing, etc. Polkadot-sdk contains various components that can be used indepedently or as a whole. One of such components is networking layer. Desipte many research on similar components in Ethereum, for example, there are no solid research about polkadot-sdk networking layer.

### Research goals overview

First, actual knowledge about networking layer of polkadot-sdk is to be extracted from engineering implementation and conversating with engineers working on mentioned implementation. Networking protocol is itself based on `rust-libp2p`, which is also widely used in different distrubuted systems (`Filecoin`, for example).

Next is to categorize the properties of the protocol, review it's distinguished characteristics, limitations, andvatanges and disadvantages against common principles used in such systems with dynamic topology.

Third, compare those properties to other networking layers of other networks (`Ethereum`, `Bitcoin`, `Solana`, and others).

Forth, provide engineering recommendation about improving particular aspects of the protocol.

### 1. Extracting knowledge

Polkadot-sdk networking layer is a p2p protocol where all participants can theoretically choose completely their own behaviour. In practice though, it is more of a configuration of extistant behaviour. Whether this is optimal is a further subject of the research.

Implementation of the protocol is documented here: https://paritytech.github.io/polkadot-sdk/master/sc_network/index.html and implementation itself is hosted here: https://github.com/paritytech/polkadot-sdk/tree/master/substrate/client/network.

Number of metrics is suggested, but not limited to:
1. Speed of information propagation.
2. Throughput of the system.
3. Resistant to attacks ("eclipse", "shadow chain", others, which applicable).
4. Resistant to network split/finality stalls.
5. Overall security (encryption, key rotation, etc.)

Other metrics could be suggested by research fellows.

### 2. and others: to be continued