The meaning of tsung output (graphs-user-simultaneous)

I'm trying to test my Tigase XMPP server with tsung (load test). The tsung read a list of 'username;password' from .csv file. For basic test the .csv file contains only 3 users: user1, user2 and user3.

In the tsung.xml configuration file I configure 12.5 connection per second, and each connection stay alive 2000 second.

I have few question:

1. If I have only 3 users, what should the tsung do after all of the 3 are connected?

2. In the output graph (graphs-user-simultaneous) I see after a while 2000 connected user. How could it be?

3. What is the different between the red and green lines? I read somewhere that "connected" is the current connected, If it's true then what the green line means?

tsung status:

Tsung is running [OK]
 Current request rate:    32.59 req/sec
 Current users:           415
 Current connected users: 384
 Current phase:           1

tsung graph:

Thanks!

1. if you read your file in sequential order the 4th read will get the first line
2. the number of generated user does not depends on your datas files but on what on set in the section
3. green is the number of tsung users generated, and the red the number of them with a tcp session active on the target

More info in the docs https://tsung.readthedocs.org/en/latest/reports.html#available-stats