PIX 515 VPN Performance question

[tstout]

I'm bringing up a T1 connection using a PIX 515E firewall. We'll be configuring a VPN lan-to-lan tunnel, as well as a number of VPN client connections. I only have 50 users or so, and don't really see the need to go with the VAC+ and unrestricted license to use 3DES vpn. Does anyone have any experience with the performance decrease in using software encryption/decryption? is it worth the extra $3k for the VAC and UR license?

[shannong]

If the encrypted traffic and all other connections will be traversing the T1 and therefore limited to 1.5 Mbps, you'll have no performance problems using a 515E in this type of configuration with only 50 users and no VAC. You'll be bandwidth bound before the performance of the firewall becomes an issue.

Don't forget about the impact of a DMZ though. If you have a server out there with a lot of traffic, especially backups/file copies, it can create significant impact on the firewall as the interfaces are 100Mbps.