Perimeter Router Capacity Planning:
i have some difficulty in capacity planning, or right sizing a perimeter router and a firewall, yes we do have the recommendations from cisco, that a 1841 or a 2801 are designed for 1 T1/E1 link, the fact is these are expensive(from a third world country's prospect) routers and in this age of broadband we do have circuits in the multiples of E1/T1 how far can we push these routers in terms of bandwidth, i can understand that this depends heavily on the feature set enabled on the device but could never get a clear picture, kindly shed some light on the topic.
The Firewall is a mystical device the smallest of them like ASA 5505 have 150Mbps of throughput but does that mean i can use it for a 30+ Mbps circuit i guess no, but why??, that is what i don't know.
One last question which might sound stupid, but again to much networking would never be enough, i can never understand the case for a 1 Gbps access ports for an average enterprise user, Gigabit switches at access layer are quite expensive when compared to their Fast Ethernet counterparts, when is it must to have a Gigabit switch in your access layer.