Direct call vs Block call

Hi for all,

i 've installed asterisk with isdn trunk with alcatel pabx.
For alcatel users use asterisk lines, should dial 0. In default configuration in alcatel, if user dial 0 this error occour:

!! Unexpected Channel selection 3
– Extension ‘’ in context ‘default’ from ‘’ does not exist. Rejecting call on channel 0/31, span 1

In alcatel we’re enable block dial, so alacatel only send to asterisk when user end dialing.

How i permit the first case to work ??