# NDN Content Store and Caching Policies: Performance Evaluation
## 4 Related Work
\begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Reference** & **Topology (\# Nodes)** & **Caching Policy** & **Number of CS, in \%** & **Size of CS** \\ \hline [PERSON] et al. [5] & Abilene (11), GEANT (41) & LFU & 20, 40, 50, 80, 100 (of \# nodes) & 1000 contents \\ [PERSON] et al. [7] & Hierarchical (20) & LFU, LRU, _CCP_\({}^{\,2}\) & 100 (of \# nodes) & 40–60\% of 200 contents \\ [PERSON] et al. [51] & Synthetic, _Sprint_ (52) & FIFO, LRU, _UC_\({}^{\,2}\) & 100 (of \# nodes) & (2–20\% of cache \({}^{\,1}\) \\ [PERSON] et al. [50] & Synthetic, _Sprint_ (52) & FIFO, LRU, _UC_\({}^{\,2}\) & 100 (of \# nodes) & (2–20\% of cache \({}^{\,1}\) \\ [PERSON] et al. [6] & Hierarchical (150–3000) & LRU, LFU, FIFO, NC-_SDN_\({}^{\,2}\) & 5 (of \# nodes) & 1 \\ [PERSON] and [PERSON] [10] & Synthetic (10) & LRU, FIFO, _PPNDN_\({}^{\,2}\) & 30 (of \# nodes) & 10–70\% of 1000 contents \\ [PERSON] et al. [11] & Vehicular network (108) & LRU, FIFO, _ACCP_\({}^{\,2}\) & 100 (of \# nodes) & 50, 75, 100, 125, 150 MB \\ [PERSON] et al. [13] & Binary tree topology (12) & LFU, LRU, FIFO, _Popul_\({}^{\,2}\) & 100 (of \# nodes) & (10–190 MB) \\ [PERSON] et al. [12] & Layered topology (169) & LRU, _PopNetCod_\({}^{\,2}\) & 27 (of \# nodes) & 0.9–2.3\% of 540,500 contents \\ [PERSON] et al. [14] & Substrate topology (15) & LRU, LFRU, _adaptive LRFU_\({}^{\,2}\) & 100 (of \# nodes) & 100–100\% \\ [PERSON] et al. [15] & GEANT (100) & LRU, FIFO, LFU, _LFRU_, _IMU_\({}^{\,2}\) & 100 (of \# nodes) & 4–20\% of 100,000 contents \\ [PERSON] et al. [16] & \(k\)-_trv_ trees (\({}^{\,1}\)), Scale free topology (\({}^{\,1}\)) & FIFO, LRU, _CaDaCa_\({}^{\,2}\) & 100 (of \# nodes) & 10% of 1000 contents \\ Present work & Testbed (43), Abilene (11) & LFU, LRU, FIFO, Random & 5, 20, 30, 40, 50, 80, 100 (of \# nodes) & 1000 contents \\ \hline \hline \end{tabular} \({}^{\,1}\) Value not provided. \({}^{\,2}\) Policies proposed by the referenced authors.  
\end{table} 
Table 1: Some studies on caching policies. All studies use LCD as the default caching strategy. section, the conclusions from this study are partially divergent with the results achieved in the present work. The study by [7] evaluated the performance of LRU, LFU and their proposed replacement strategy considering the CHR, traffic and server load. The study did not indicate the consumer request rate. In addition, the number of CS in the network is fixed, only varying in size, which is defined as the percentage of cached capacity by the total capacity. Their results, with LRU performing better than LFU, is only consistent with one of our scenario composed by various consumers and only one producer. The work by [50; 51] evaluated FIFO, LRU and their proposed replacement strategy. The metrics considered are the CHR and the hop-count. The study considered all nodes equipped with CS, only varying their size (2% to 20% of CS) based on the similarity of requests. Consumers request content at a rate of 1000 packets/s. All the other selected studies ([10; 11; 12; 13; 14; 15; 16]) present a fixed number of CS, only varying the size of the deployed CS, and compare the performance of their proposed solution with some of the state-of-the-art methods, as presented in the table. All studies consider a simple network with only one content source.