General Questions

I have a client that is interested in m0n0wall but it concerned about the number of concurrent sessions.  The firewalls they looked at in the past were sized/licensed by concurrent sessions; the Cisco ASA-5505 supports up to 25,000 with the extended license for example.  I have several m0n0wall boxes in my hosting environments and have never had a problem or even thought to see how many concurrent sessions I using at any given time.  Is there a way to see how many concurrent sessions I have going?  Is it as simple as looking at firewall states (but not limited to 300?).

Thank you!

Eric