Meeting issue!

Hi ,
i have implemented asterisk 1.4 , but the meeting functioning is wrong ; when i dial the meeting number i have a message of wrong ID number. I don’t know how to solve a problem !! Maybe i didn’t use a good manner why dialing , can some one give me a process or a good configuration issu

Meetme.conf : conf => 900
extension : ;extensiion pour conference meet me()
exten => 900,1,MeetMe(900,i,555)


Please dial into this and post the CLI output, this will help to diagnose the problem.

Did you install zaptel ? and ztdummy ?