packet scheduler

Q. Under FreeBSD 7.0 patch level 5, I’m getting following warning message:

Enabling pf.
No ALTQ support in kernel
ALTQ related functions disabled
No ALTQ support in kernel

I need ALTQ support for my FreeBSD box. How do I enable ALTQ for Class Based Queuing (CBQ) to divide a connection’s bandwidth into different classes or queues to prioritize traffic based on filter rules?