Can a typical firewall appliance handle things like throttling requests per user (per IP)?

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http://serverfault.com – I'm intending to purchase a Cisco ASA 5510, but am wondering whether or not I should expect to be able to do things such as mentioned in the question title with a typical firewall (or specifically with the aforementioned model, if you know), as well as things like blocking specific HTTP User-Agents, and limiting the size of HTTP request bodies, setting up more complicated throttling rules like requests per minute with burst allowances, etc. I know these things can be handled by my web server, but would prefer to be able to offload the work on my firewall, and also remove the necessity of havi (HowTos)