Handbook:Advanced Server Configuration:Dial String Rules

A dial string specifies how to dial the telephone in order to reach a destination facsimile machine, or other device. This string is supplied by a user with each outbound job. User-supplied dial strings need to be processed in two ways by the HylaFAX server processes: to craft a canonical phone number for use in locating the receiver's capabilities, and to process into a form suitable for sending to a modem. In addition client applications may need to process a dial string to formulate an external form that does not include private information such as a credit card access code. Phone number canonicalization and dial string preparation are done according to dial string processing rules that are located in a file specified in the server configuration file;

DialStringRules: etc/dialrules

The generation of an externalized form for a dial string is done by rules that optionally appear in DIR_LIBDATA/dialrules on client machines (where DIR_LIBDATA is the pathname setup at the time the software is configured for compilation).

Dial string rules are an important part of HylaFAX as they permit local PTT conventions to be handled entirely on the HylaFAX server machine (e.g. the need to dial "1" before certain numbers but not others). Client applications are then free to use a canonical format for phone numbers that is location independent. Dial string rules combined with the ModemDialCmd also permit modem-specific idiosyncrasies such as the syntax for doing a "flash hook" to be handled transparently. Finally, dial string rules can be used to provide dialing aliases such as mapping "a-zA-Z" to the corresponding numeric codes.

Consult dialrules(4F) for detailed information.