| Internet Engineering Task Force | D. Huang |
| Internet-Draft | ZTE |
| Intended status: Informational | June 28, 2017 |
| Expires: December 30, 2017 |
Allied and private blockchain as detnet use case
draft-blockchain-as-detnet-use-case-00
This draft brings blockchain into the detnet use case list. Generally speaking, blockchain is both a technical term and a blockchain-based industry, which is spreading into a wide range of industries other than the thriving bitcoin. Blockchain would have to require the supporting network offer deterministic networking service rather than the ongoing best-effort, because of its inherent p2p and frequent multicast working mechanism.
Blockchain working process, its current network mechanism and challenges ahead, as well as requirements to detnet will be illustrated in the draft.
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Blockchain is emerged together with bitcoin, while the latter operates and thrives in the open Internet which is not supposed to be within the scope of Detnet. Nevertheless, blockchain has spread far beyond its original host into various industries, such as smart manufacturing, logistics, security, legal rights, to name a few, because of its inherently innovative non-central business model.
Bear potential challenges from the bitcoin in mind, industry players realize it makes good sense to take advantage of blockchain in a controlled circumstance rather than the wild open Internet. Both allied and private blockchain run in designated and carefully managed network in which deterministic networking requirements could be addressed in Detnet.
Block runs as a container of a batch of primary items such as transactions, property records etc. The blocks are chained in such a way that the hash of the previous block works as the pointer header of the new block, where confirmation of each block requires a consensus mechanism. When an item arrives at a blockchain node, the latter broadcasts this item to the rest of nodes and the rest of nodes will receive and verify it and put it in the ongoing block. Block confirmation process begins as the amount of items reaches the predefined block capacity. After the confirmation process, the node broadcasts its proved block to the rest of nodes to be verified and chained.
The network treats the traffic from blockchain basiclly on best-effort , while efficiency and even raison detre of some blockchain applications such as security transaction, payment etc demand deterministic networking service to reduce latency and packet loss as low as possible.
Blockchain node communication and coordination is achieved mainly through frequent point to multi-point networking. Nonetheless, the node transports both the items and the blocks to the other nodes on a point to point basis, namely creates connections with every node individually when it comes to the supporting network.
When a node initiates, it firstly requests other ongoing nodes's address from a specific entity such as DNS, then creates connections with other nodes. If node A confirms an item, it sends the item to other nodes through the staying connections.
Once a new block in node completes to be proved among the nodes, This node starts propagating this block towards its neighbor nodes. Assuming node A receives a block, after verification, it sends invite message to its neighbor B, B checks if the designated block is available, it responds Get message to A if the block is unavailable, and A send the complete block to B. B repeats the process as A to start the next round of block propagation.
As far as blockchain traffic is concerned, it's hard to say there is significant pressure over the network because the data volume from both block and item stays between hundreds of bytes to a couple of mega bytes. Apart from the consensus mechanism of blockchain itself, the blockchain data needs to be transported with as low latency as possible in the network to guarantee the blockchain consensus process efficiency.
Blockchain addresses its security issues mainly in application level, where the cryptography as well as hash-based consensus play a leading role preventing both double-spending and malicious service attack. However, in the case of allied and private blockchain, it concerns the industry participants the network supporting blockchain could be highly likely the target of attack, particular for the scenarios where time efficiency is crucial and service is less delay tolerant.
In allied and private blockchain, it runs in L2 or L3 VPN in some cases, but when it comes to the specific blockchain traffic transmission, namely the item broadcast and the block propagation among the participating nodes, the network has not yet address its deterministic requirements industry player start to concern.
Blockchain requires deterministic networking service when it comes to accelerating consensus process. It would be valuable to design a network mechanism with the following properties: