I'm facing a VPN connection with a Netscreen-25 on "our" side. The specific traffic will be between 4 and 8 Mbps. Which encryption method should I prefer performance-wise? AES(128) or 3DES? I could not find any info on specific encryption accelaration circuits in the NS-25.
AES encryption is in software, while 3DES is in hardware. If you want more security, go with AES. If you want faster performance, go with 3DES. As always, optimum performance is gained with less security, and vice versa.