I apologize for the vague set of data I have presented you with. You could have made some basic assumptions about it though. I will now set the example case more in detail.
Let's assume the usage is built up from these mentioned five channels using a basic mIRC client. The total amount of users from all channels combined is around 250(100, 100, 25, 15 plus random users). While in IRC, the person in question would participate actively in at least one channel, sending in commentary with an average length of some 22 characters/comment with an average speed of 1 comment/10 seconds. Other users talking would amount to an average of 1 comment/5 seconds with average lines of 15 characters/line.
Thus:
Input: 22 characters every 10 seconds plus additional "ping", "whois", "mode" etc. lines.
Output: 15 characters every five seconds plus additional "join", "part", "topic" etc. lines.
Such total activity could be described as active chatting. No DCC or such features would be used in this example calculation.
Can you now make anything of the task?