The TCP/IP stack plays an important role in terms of data transmission, traffic control and address assignment in the Internet of Vehicles (IoV), which has seen phenomenal growth in recent years. However, with the increasing technical requirements and daily demand in IoV, the drawbacks of traditional TCP/IP protocols, e.g., weak scalability in large networks, low efficiency in the dense environment and unreliable addressing in high mobility circumstance, become non-trivial especially in vehicular environments. Fortunately, the emerging Named Data Networking (NDN) technology provides a good choice to address the above issues in vehicular environments. Specifically, the introduced content store module in NDN which caches the sent/received contents, can greatly improve the networking performance by suppressing redundancy as well as enriching diversity. With aforementioned motivations, we thoroughly studied previous works on Vehicular Named Data Networking (VNDN) with emphasis on content caching, and then demonstrate the feasibility and necessity for employing NDN in vehicular environments with the help of content caching. Subsequently, we further strengthened the importance of cache selection and replacement strategies in VNDN framework, which is positioned to meet the challenges of data transmission efficiency and resource consumption by leveraging in-network vehicular caching. After that, we engaged in an in-depth survey on the existing cache selection and replacement schemes in VNDN, with their applicability compared. Next, further challenges during caching design were elaborately analyzed considering the specific characteristics of VNDN. Finally, we highlighted the potential research directions which may shine lights on the promising efforts to improve the performance of VNDN content caching.
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