The question is clear I think. I used 3.5GH/s because that's what the upcoming ButterflyLabs Jalapeno will run. Assume it's mining for an average mining pool with 3.5GH/s (only bitcoins).
I'm interested in maintaining one on a spot where I can get electricity for free, but I have limited internet access.
The internet traffic for any miner is generally minimal and in most cases the miner speed is irrelevant. The Getwork protocol would at most make a small request every second, but with extensions such as rollntime, one can make the request less frequently. You can roughly see how much data is being sent from the examples provided here. Generally, you shouldn't worry about the internet speed or bandwidth.
