Say the average web page is 100kb, and assuming gigabit connection in the office, then that's about a thousand pages per second. If the office switch is on 10gbit that would work out to 4000p/s naively counting. But we're in the same order of magnitude for the speed even on gbit, and we're not accounting for gzip, and the actual average page size might be a bit lower too.
Everything was on 10gigE. The average page size was around 17KB gzipped. Everything's a careful balance between CPU, memory, storage, and message throughput between machines.
Apple's corporate network also had incredible bandwidth to the Internet at large. Not sure why, but I assumed it was because their earliest data centers actually ran in office buildings in the vicinity of 1 Infinite Loop.
