HLLR: Highest Lifetime Least Request policy for high performance Pending Interest Table

Pending Interest Table (PIT) in Named Data Networking (NDN) architecture is complex in the forwarding operation in both upload of Interest packets and download of Data packets. PIT is considered useful for so many reasons in the centric-networking. These among other operations include: reducing bandwidth usage, communicating with no prior knowledge of publishers and subscribers, loop and packet loss detection and best security. However, despite the numerous advantages of PIT, hardware challenges, including PIT are still crucial in respect to NDN management for better memory efficiency. Due to the high access frequency to the PIT, it is essential to understand its functionality, and the effect it has on PIT performance, especially since PIT overflows. In our quest for designing a replacement policy as close to optimal as possible, we proposed a new replacement policy in PIT. This paper presents a new replacement policy named Highest Lifetime Least Request (HLLR). HLLR is designed to replace entries in the PIT which has the minimum number of incoming faces with maximum Lifetime. We have tested the policy using ndnSIM simulator and evaluated the results with some existing PIT replacement policies, i.e. Persistent (default), Least Recently Used (LRU) and Random. HLLR policy, design and evaluation are presented in this paper, aimed at obtaining better performance in case delay time, minimum Interest retransmission and Interest drop. The significance of this study is thus, it presents a conceptual model in order to tackle the issue of Interest replaces delay, which will be very much useful for managing the PIT when it is full.