I am designing a campus network, and the design looks like this:

LINX is The London Internet Exchange and JANET is Joint Academic Network.

My goal is an almost-fully redundant with high availability, because it will have to support about 15k people, including academic staff, administrative staff and students. I have read some documents in the process , but I am still not sure about some aspects.

I want to dedicate this one to firewalls: what are the driving factors in deciding to employ a dedicated firewall, instead of an embedded firewall in the border router? From what I can see, an embedded firewall has these advantages:

• Easier to maintain
• Better integration
• One less hop
• Less space requirement
• Cheaper

Dedicated firewall has the advantage of being modular.

Is there anything else? What am I missing?