Agent's status don't became 'BUSY'

Dear All
I am using asterisk for real time. When an agent is taking call its status still does " SIP/201 (dynamic) (Not in use)". How can i over come this problem.

You need to set a call limit before Asterisk will monitor use levels on SIP channels.

Thx I did it and it working. But it only works when i make user in sip.conf file. But if we make user in realtime of sipbuddies its status does not changeā€¦ I experimented call limit is not working in sipbuddies table

Now Please guide