strongSwan

Hello,

We're using StrongSwan and FRR. We've Intel Xeon E5-2620 with x 24CPU. The KSOFTIRQ processes are utilizing only 0 and 15 CPU. Sometimes it uses ~50% CPU usage. Server have 2x10LAN cards and IPSec traffic is only ~2gbs. But it's encrypted and packets are in different sizes. Where could be the case ? OS is Centos.
1) is it possible to tweak that CPU utilization would be smaller ?
2) is it possible to load balance the load across all CPUs ?

Thank you