# An ICN-Based IPFS High-Availability Architecture
## 2 Related Work
### Information-Centric Networking  
In today's networks, there is more focus on the data than on where the data are located. Information-Centric Networking (ICN) is a new type of network architecture that aims to solve the problem of semantic overload in traditional IP networks. Currently, some of the more successful ICN cases include NDN [32], CCN [33], MobilityFirst [34], DONA [35], SEANET [36], etc. The core feature of these ICN networks is the separation of identifiers and locators, and therefore, further name resolution services between data IDs and NAs are needed. Typically, two name resolution service approaches are used, the name-based routing approach and the independent name resolution approach.  
Among them, NDN and CCN are using the name routing-based approach, which is done by coupling routing with name resolution without the need for an additional resolution system. However, this approach completely reverses the existing data routing method, which requires changes to most of the existing network infrastructure, resulting in a non-negligible cost overhead. MF and DONA, on the other hand, both use an independent name resolution approach, which is done by pre-establishing an independent resolution system. The requestor obtains the service address information of the data source through the resolution system, and then accesses the data through normal address routing. Compared with the name routing-based approach, the independent name resolution approach can help ICN networks to make incremental deployments on existing networks with lower cost overhead.  
[PERSON] et al. first proposed the improvement of IPFS data delivery performance by using NDN network to reduce the number of redundant packets caused by the Bitswap mechanism [18]. The routing of the NDN network mainly relies on the content base (CS), forwarding information base (FIB), and pending interest table (PIT) to record the data forwarding path, when the data are successfully retrieved, and the data are delivered to the requester along the reverse path according to the forwarding records in the PIT table. The DHT routing mechanism of IPFS is still able to provide forwarding hints to the network layer. For redundant packets, each node updates its own PIT information after receiving the first delivered data, and does not send data to the requester path again when the subsequent duplicate data reach it. However, the NDN routing method may require the existence of flood lookups due to the lack of precise localization, and the retrieval information needs to be bounded by adding a survival time.  
Current independent name resolution systems have cloud-based architecture systems [34], multi-layered DHT architectures (MDHT and HSkip) [37], and determined latency (DLNR) [38] implementation schemes. While this paper focuses on combining IPFS networks with ICN network architectures with deterministic time-delayed resolution systems. As shown in Figure 1, DLNR proposes an Enhanced Name Resolution System (ENRS) by dividing the network into multiple deterministic time-delayed resolution domains with resolution delay as a constraint and deploying independent resolution nodes within the resolution domains to maintain the one-to-many relationship between identifiers and locators. Logical nesting is achieved by dividing the physical network into multi-layer coverage networks and deploying different levels of delay constraints in different coverage networks. All the resolving nodes jointly maintain a tree organization structure, and the leaf nodes of the tree represent the resolving domains with the lowest level of experimental constraints. The resolution nodes within these resolution domains can help users in the region to achieve a fast location of information data.