Criteria that could be used to evaluate and compare firewall technologies: 

• Extent to which a firewall must support and enforce a usage (e.g., Internet) policy
• Adherence to an existing agency standard that details the specific firewall that should be acquired
• Existence of a certification or warranty by the vendor to perform in an acceptable manner
• Traffic volume and connectivity requirements that the firewall must support
• Specific hardware and software required by the firewall
• System administrative skills required to support the firewall and what vendor support is available
• Cost of firewall 

Current performance considerations: 

• Firewalls can range from host based personal firewalls serving a single user and a simple security policy to networked based enterprise firewalls serving large organization’s with complex security policies. 
• The costs can range from around one hundred dollars to over ten thousand dollars.
• Packet filtering firewalls tend to be faster than application-level firewalls and consequently tend to have greater throughput and lower latency.
• Firewall appliances, at the low end, do not require extensive OS expertise, thus reducing the amount of support time required to keep the firewall secure, where-as high end enterprise firewalls tend to be quite complex, requiring extensive OS and maintenance expertise.

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