HP-UX IPSec vA.02.00 Performance and Sizing White Paper

AES, DES, and 3DES Encryption
The following charts display throughput, CPU utilization, and service demand data for raw IP data
transmission and the following HP-UX IPSec transfer types:
• ESP-AES
• ESP-DES
• ESP-3DES
Throughput
Figure 1 shows the throughput rates in Megabits per second (Mb/
s).The throughput rates for ESP-DES
and ESP-AES are close to the throughput for raw IP. Of the three encryption types, ESP-AES provides
the strongest encryption with excellent throughput. Compared to raw IP performance, ESP-AES
performance degradation is less than three percent (3%).
The throughput rates for all packet types, including Raw IP, show a dip in performance as the packet
size approaches 768 bytes. This reflects the inherent inefficiency when sending packets that are
slightly larger than one-half the link maximum transmission unit (1500 bytes). The packets are too
large to concatenate two to fill the link buffer, but sending a single packet over the link leaves nearly
half the link buffer empty.
Figure 1. One-Way Itanium Throughput for Raw IP, ESP-AES, ESP-DES, ESP-3DES
5