Experimental performance evaluation of VPN implemented with strongSwan client and Cisco IOS IPSec gateway

Virtual private networks have gained great popularity because they provide secure connectivity at low cost. Remote-Access IPSec VPN topology establishes a secure tunnel between a workstation with VPN client software and VPN gateway devices. Most of the commercial solutions for VPN client software are limited to Microsoft platforms, which limits the utilization of this technology by Linux users. Scope of work of this paper was to perform the integration of strongSwan VPN client (open-source IPSec solution for Linux) with one of the most common commercial implementation of IPSec for network devices, Cisco IOS IPSec platform. Performance evaluation was carried out in order to measure important characteristics of IPSec connection between strongSwan VPN client and Cisco gateway. The evaluated characteristics included: TCP and UDP throughput, RTT, jitter and packet loss.