[isdn_incoming]

exten => 1234567,1,Goto(testnummer,${EXTEN},1)

[testnummer]
exten => 1234567,1,NoOp(Inbound Context: Testnummer - ${EXTEN})
; same => n,DumpChan()
 same => n,Dial(SIP/16_yeal52p)
 same => n,Hangup()