I have a question. I am collocating and using say 60GB of transfer a month. Now I am switching to a new provider. However then don't charge by transfer they charge by bandwidth. Like 128K, 256k, 512k, 1MBPS, 2MBPS, etc. Can you help me out? What should I choose? What is the general rule of thumb for these connections?

1 Mbps ~ 325 GB

So, based on that I would say should be fine with a 256 kbps connection. One thing that can change the rule is 95th percentile billing. You will normally pay 1.5 X the bandwidth that you actually use.

Ya I know about that rule. So lets say you have a 256K fixed line so that would be about 80GB a month? What happens if your server goes over 80GB on a fixed line?

I think that is impossible because the line will not be able to transfer and more then 256Kps

Hmm....

Another thing I'm confused on is 1MBPS. Doesn't 1MBPS mean 1 Mega Byte Per Second? If this is so then a 1MBPS line should be able to transfer a lot more than 320GB of transfer in a month.

nope, it means one Mega BIT per second, and there are 8 bits to a byte!

1 Mbps = 1 Megabit per sec (not megabyte). 8 bits is about equivalent to 1 byte.

Here's how you come up with 325 GB:

1 Megabit x 60 seconds x 60 minutues x 24 hours x 30 days / (divided) by 8 = about 325 GB per month.

Now that helped a lot. Thank you. Just one more question. If I have a 1MBPS line and I'm using around 300GB transfer a month, are all the sites going to be slow because I'm getting near the limit?

It depends. If they cap it at 1 Mbps (not burstable beyond that), then it is virtually impossible for you to get 300 GB per month from that line, unless your site is getting the same amount of hits every second of every hour of everyday. If your traffic were this way, then you would be able to do 300 GB or so per month form a 1 Mb line... but like I said... it's not likely.

Let me give you an example.. If a site is averaging 30 GB data transfer per month, you have to keep in mind that Internet traffic is bursty. At certain times of the day, your traffic can reach 5, 10, or 20+ times your average bandwidth output. If you have really bursty traffic at certain times of the day that's equivalent to 10 x's your average bandwidth/data transfer (30 GB x 10), then a 1 Mbps line would be ok for 30 GB's of average data transfer per month. This, assuming that you want uninteruptable traffic.

However, if you're averaging over 100 GB per month, typically a 1 Mbps line (capped) is out of the question. Your server would most likely be crawling at times.

In general, for 300 GB's of data transfer... to be safe, your bandwidth will probably need to be burstable to a 5 - 10 Mbps line.

So if my server is using an average of 100GB of transfer a month then I should get a 1MBPS line burstable to what?