Call forwarding is used when the application is not available to take a call or the application is programmed to answer the call on another extension. This means that all calls are forwarded to another preprogrammed telephone number. For the application, forwarding a call means that an incoming call can be treated differently.

The application can specify call-forwarding conditions, based on the following criteria.

• The origin of the call (internal, external, selective, based on caller ID)
  
  
• The status of the address (busy, no answer, unconditional)
  
  
• The destination address to which calls are to be forwarded
  
  

The application can use the lineForwardfunction to forward calls that are destined for the specified address on the specified line, according to the specified forwarding instructions. lineForwardalso provides a combination of forward and do-not-disturb functionality, and can cancel forwarding that is currently in effect.

The LINEFORWARDLISTstructure describes a list of forwarding instructions and parameters that are requested for forwarding calls on an address, or on all of the addresses on a line. The LINEFORWARDstructure describes an entry of the forwarding instructions. A number of different constants can be set by using LINEFORWARD, and these are shown in the following list.

• All calls are forwarded unconditionally, regardless of their origin.
  
  
• All calls are forwarded internal calls unconditionally.
  
  
• Forward all external calls unconditionally.
  
  
• Forward all internal calls on busy.
  
  
• Forward all calls on no answer, regardless of their origin.
  
  
• Forward all external calls on no answer.
  
  
• Forward all internal calls on busy or no answer.
  
  

See Also