Modeling and analysis of core-centric network processors

Abstract

Network processors can be categorized into two types, the coprocessors-centric model in which data-plane is handled by coprocessors, and the core-centric model in which the core processes most of the data-plane packets yet offloading some tasks to coprocessors. While the former has been properly explored over various applications, research regarding the latter remain limited. Based on the previous experience of prototyping the virtual private network (VPN) over the IXP425 network processor, this work aims to derive design implications for the core-centric model performing computational intensive applications. From system and IC vendors' perspectives, the continuous-time Markov chain and Petri net simulations are adopted to explore this architecture. Analytical results prove to be quite inline with those of the simulation and implementation. With subsequent investigation, we find that appropriate process run lengths can improve the effective core utilization by 2.26 times, and by offloading the throughput boosts 7.5 times. The results also suggest single-process programming, since context-switch overhead impacts considerably on the performance.