Provided by: hylafax-server_4.2.5-1_i386 bug


       callid - Call identification access control list


       The HylaFAX configuration parameter QualifyCID specifies whether or not
       the identity or identifier of an inbound call should be checked against
       an  access  control  list  before the telephone is answered.  This both
       enables call  screening  against  those  values  and  fax  routing  (in
       faxrcvd’s  FaxDispatch)  based on those values.  If a modem is attached
       to a phone line that has Caller-ID or DNIS service, and  QualifyCID  is
       non-null,  then only the calls identified by strings matching CIDNumber
       (CallID1) in the file (typically etc/callid) will be answered.

       Patterns are specified one per line and must  conform  to  the  regular
       expressions   syntax  specified  by  POSIX  1003.2;  see  re_format(7).
       Comments may be included; they are introduced with the ‘‘#’’  character
       and  extend to the end of the line.  Any trailing white space on a line
       is ignored (for convenience when comments are used).

       If a line begins with ‘‘!’’, then  the  regular  expression  identifies
       callers that should be rejected; otherwise regular expressions identify
       clients whose calls should be accepted.  The order  of  patterns  in  a
       CallID  file is important.  When a call is to be answered, the faxgetty
       process will compare the phone number presented by  the  modem  against
       the  patterns  in  the  access  control list in the order in which they
       appear in the file.  The first pattern that matches the client’s number
       is used to decide whether to accept or reject the call.  If no patterns
       match the phone number then the call is not answered.  Thus if you want
       to  accept all but a restricted set of calls, the last line in the file
       should be ‘‘^.*$’’.

       Note that regular expression patterns should  be  written  to  match  a
       phone number exactly.  That is, patterns should be of the form:

       where  the ‘‘^’’ and ‘‘$’’ characters are used to specify the start and
       end of the matching phone  number.   Additionally,  regular  expression
       patterns  should handle white space that may appear in known locations.
       For example,
            ^([+]1){1}[ .-]*415[ .-]*555[ .-]*1212.*$

       matches the following phone number strings:
                  415  555  1212

       Finally, note that regular expressions can  be  used  to  specify  many
       numbers with one pattern.


       The  CIDNumber  (CallID1) configuration parameter described in hylafax-
       config(5) is used  to  store  call  identification  information.   This
       parameter  must be present in the per-modem configuration file for call
       identification  screening  to  function  properly.   If  QualifyCID  is
       defined,  but  no  CIDNumber (CallID1) is specified, then no match will
       occur and all incoming calls will be ignored.

       Call identification data is only sent once by the telco or PBX, and the
       timing  of  its  arrival  varies  upon the telco or PBX and the type of
       line.  If HylaFAX is configured to answer via  RingsBeforeAnswer  prior
       to  the  arrival of the data, then all CallID values will be null.  For
       example, on US analog lines, caller-ID data  is  usually  sent  between
       RINGs  1  and 2.  In this situation, RingsBeforeAnswer should be set to
       ‘‘2’’ or greater.


       faxgetty(8), hylafax-config(5), re_format(7).

                                 May 28, 2001                        CallID(5)