Bandwidth Estimation: If our service is getting 2TB of data every day, this will give us 25MB of incoming data for each second.
2 TB / 86400 sec ~= 25 MB/s
Since each incoming message needs to go out to another user, we will need the same amount of bandwidth 25MB/s for both upload and download.
Should it be closer to 25MBps? 2 / 86400 ~= 2.3 * 10^-5.