Hi,
When I run MultiDial, for example:
exten => s,1,Dial(SIP/200&SIP/201&SIP/202)
It works fine, and the three sip accounts ringing. 
But, after the call, how can I know who answered call ? 
Thanks.
Regards.
you can see in asterisk console or CDR .
you can use real-time operating panels such as “Flash Operating Panel”