STUDYING EFFICIENCY OF DATA CACHING STRATEGIES IN INFORMATION-CENTRIC NETWORKS

Today, the architecture of computer networks using IP addressing is focused on interaction between network devices with «binding» of data objects to specific sources, which leads to a decrease in bandwidth and network congestion. In information-centric networks (ICN), routing and caching of data objects on intermediate network nodes during transmission from source to recipient is performed using unique names. The purpose of the study is to analyze the performance of various caching strategies in terms of cache hit rate and request response time for data objects. Materials and methods. The following caching strategies were selected for the study: Leave Copy Everywhere, Leave Copy Down, Probabilistic Cache, random caching, Bernoulli probabilistic caching, symmetric hash routing scheme, asymmetric hash routing scheme, multicast scheme. The following metrics were calculated: cache hit rate, time delay in delivering the requested data object to the recipient, channel load when transmitting the data object, and the length of the data object’s path. The metrics were measured taking into account the following characteristics: asymmetry in the distribution of data object popularity, the total size of network caches of intermediate nodes as a share of the total number of data objects. The simulation was performed for three network topologies: GARR (Italian academic network), GEANT (European academic network), WIDE (Japanese academic network) using the Icarus 8.0 simulator. Results. The use of symmetric hash routing and multicast schemes allowed us to obtain the highest cache hit rate. The lowest cache hit rate in most tests is observed when using the asymmetric hash routing scheme, since the path of a data object to the recipient may not pass through the router responsible for caching. When using symmetric hash routing and multicast schemes, it was possible to obtain a lower delivery delay compared to other strategies. When using the Leave Copy Down caching strategy, the delivery delay with an increase in the data object popularity asymmetry indicator takes smaller values ​​than that of the hash routing schemes. The highest delay among the strategies under consideration is observed when using the asymmetric hash routing scheme. The use of the hash routing scheme leads to a relatively high value of the communication channel load parameter. The channel load indicator values ​​for such strategies as Leave Copy Everywhere (LCE), Leave Copy Down (LCD), Probabilistic Cache (ProbCache), random choice caching (RAND_CHOICE), Bernoulli caching (RAND_BERNOULLI) do not differ much from each other. The use of hash routing schemes leads to an increase in the length of the data delivery path, especially when using symmetric hash routing schemes and multicasting, since the path of the data object to the recipient may pass through the router responsible for caching, which is not always the shortest. Conclusions. Hash routing schemes with caching in some cases are a completely reasonable alternative to methods that are focused on caching along the request path and do not involve the use of hash functions to match the unique name of the data object and the router intended for caching. The practical significance of this work lies in the possibility of using the results of the study when choosing a particular caching strategy on intermediate network devices depending on the characteristics of the communication channel, in particular, the network topology and the degree of popularity of the transmitted data object.