B.136. WaitForRing()

Waits the specified number of seconds for a ring signal.
WaitForRing(timeout)
Waits a maximum of timeout seconds for a ring signal, which is only treated as valid until the second ring has completed.
Returns 0 on success, or -1 if the channel is hung up.
; Wait 5 seconds for ring, then send DTMF:
exten => 123,1,Answer()
exten => 123,n,WaitForRing(5)
exten => 123,n,SendDTMF(1234)

Note

Internal help for this application in Asterisk 1.4:
  -= Info about application 'WaitForRing' =- 

[Synopsis]
Wait for Ring Application

[Description]
  WaitForRing(timeout)
Returns 0 after waiting at least timeout seconds. and
only after the next ring has completed.  Returns 0 on
success or -1 on hangup
diff output to internal help in Asterisk 1.2:
- none -