Difficult in making a Conference with MeetMe

Hi everybody,

I’m searching to make a simple Conference Room using MeetMe.
I think to have correctly installed Zaptel and Ztdummy.
I’ve created the room but single users aren’t able to hear each other.
My configuration files are:

; extensions.conf

exten => 5557,1,Answer()
exten => 5557,n,Meetme(54321|iMcd)
exten => 5557,n,Hangup()


conf => 54321

and my logs:

– Executing [5557@sip-in:1] Answer(“SIP/218-081f5150”, “”) in new stack
– Executing [5557@sip-in:2] MeetMe(“SIP/218-081f5150”, “54321|iMcd”) in new stack
– Created MeetMe conference 1023 for conference ‘54321’
– Recording
– <SIP/218-081f5150> Playing ‘vm-rec-name’ (language ‘en’)
– Executing [5557@sip-in:1] Answer(“SIP/220-08201390”, “”) in new stack
– Executing [5557@sip-in:2] MeetMe(“SIP/220-08201390”, “54321|iMcd”) in new stack
– Recording
– <SIP/220-08201390> Playing ‘vm-rec-name’ (language ‘en’)
== Spawn extension (sip-in, 5557, 2) exited non-zero on ‘SIP/220-08201390’
– Hungup ‘Zap/pseudo-555259884’
== Spawn extension (sip-in, 5557, 2) exited non-zero on ‘SIP/218-081f5150’

Can you help me?
Thank you!