ALPHA-NUMERIC PAGER SUPPORT
This chapter describes how to configure the support for transmitting
messages to alpha-numberic pager devices using the IXO/TAP or the
This facility is implemented with the
client program, the
server program that implements the Simple Network Pager Protocol (SNPP),
server program that does the actual delivery.
Alpha-numeric pages are transmitted by contacting a server machine
that speaks SNPP and requesting that one or more messages be
delivered to one or more paging terminals.
HylaFAX implements SNPP within the framework of the hfaxd
client-server protocol process (SNPP is one of several protocols
Pager messages submitted through hfaxd result in jobs being
the HylaFAX scheduler process and these jobs are in turn handed to
the pagesend program for delivery by placing a phone call
to a pager service provider and communicating the requests
using the IXO/TAP or the UCP protocol. The used protocol can
be configured in the
according capabilities of the service provider.
Note that by using SNPP to communicate between client and server,
client applications other than sendpage can be used to
submit pager messages. There supposedly are several client
applications for Mac and Windows-based systems that use SNPP to
submit pages and a growing number of pager service providers are
providing on-line SNPP services via the Internet.
Setting up SNPP
sendpage normally tries to contact an hfaxd server process at port
444 on a HylaFAX server machine.
To enable this service hfaxd must be started with a -s
option when run standalone or with a -S option when started
by the inetd process.
For example, as a standalone server hfaxd might be started by:
hyla# /usr/local/sbin/hfaxd -i hylafax -o 4557 -s 444
to enable service for the HylaFAX client-server protocol (at the
port associated with the symbolic name ``hylafax''), the old
client-server protocol at the default port (4557), and SNPP
at the official port (444).
One of the tasks that hfaxd does in implementing SNPP is to map
client-specified Pager Identifier Numbers (PINs) to a dialstring
to use in contacting the service provider.
This work is done using rules specified in a
For example, the following pagermap file would accept only
PINs with a leading ``Sky'' followed by a number
and pass the number through as the PIN:
Note that this mapping functionality can also be used to
define aliases; e.g.
The default pagermap filename is etc/pagermap (relative
to the root of the HylaFAX spooling area).
||If hfaxd does not have a pagermap file then it
will reject all requests to submit pager messages.
Each page request received by hfaxd causes a
job to be submitted to the HylaFAX scheduler process.
The scheduling parameters for these jobs are defined by the
service level specified with the SNPP LEVE
request (typically through the -l option to sendpage).
hfaxd uses the service level to set a job's scheduling priority,
expiration time, and the time to delay in between retrying calls
to the service provider based on three maps that can
be specified with hfaxd configuration parameters.
The parameters are: PriorityMap, KillTimeMap,
and RetryTimeMap, respectively.
manual page for complete information on these parameters.
Setting up Pagesend
There are several configuration parameters associated with the
IXO/TAP and UCP support.
The most important parameters are PagerSetupCmds
The PagerSetupCmds defines
a set of commands to send to the modem to configure it for a call
to the pager service provider.
This command should usually be defined to constrain the modem to
connect at 1200 baud using V.22 (and no error correction protocol).
This parameter can be specfied in the
hylafax-config(4F) file and
may be overwritten in the
hylafax-info(4F) file to match
the service provider's modem configuration.
The PagingProtocol can be set in the hylafax-info(4F) file
to define the used protocol; it defaults to "ixo" (see below).
Other configuration parameters exist to control
esoteric aspects of the IXO protocol implementation
and should not need to be changed;
for full details.
Besides the configuration parameters described above,
other pager-related information that may need to be setup
is information in the
to constrain the maximum length
of an alpha-numeric pager message, any password string that must
be sent to the service provider during the initial login sequence,
and any non-standard parity setting to use in communication.
The pagerTTYParity setting is not needed if the service
provider correctly implements the IXO/TAP protocol.
Some providers however do not use the standard 7-bits of data with
even parity that is specified and it is necessary to specify either
``none'' for 8-bits of data and no parity or ``odd''
for 7-bits of data and odd parity..
UCP paging support has been added in version 4.0pl2. This is a new paging
protocol originating from the european Hermes project, it was
first applied to deliver GSM short messages (SMS). It can send
longer pages then IXO can, and has some other nice features,
but has a very strange character encoding. To accomodate UCP, two
new pager parameters have bin added to the
together with support to overwrite the PagerSetupCmds
defined in hylafax-config(4F):
The pagingProtocol-parameter has "ixo" as its default
value, for compatibility with previous versions of HylaFAX.
The pageSource parameter can be used to tell the
paging central who we are. You may want to put a SMS answerable
Note: This parameter should be replaced by a user-land
parameter in sendpage(1) for which the SNPP must be changed.
The pagerSetupCmds-parameter shown works for the
german GSM provider D2 and a ZyXEL 1496 modem. Consult your
modem manual and the provider for the settings you have to
Each call placed by pagesend generates a session log
similar to the logs created when transmitting facsimile.
Tracing bit 0x0002 enables logging of the IXO or UCP protocol
operation and 0x1000 enables more low-level tracing
messages that display the binary data associated with the protocol
messages (the latter is needed only when debugging subtle problems).
Both bits should be set in the SessionTracing parameter
for a modem.
The most common problems are not setting up the PagerSetupCmds
properly for the modem and service provider and service providers
that do not implement the IXO protocol according to the specification;
usually by using odd instead of even parity.
HylaFAX table of contents.
updated: Matthias Apitz / firstname.lastname@example.org
Last updated $Date: 2002/05/02 22:02:58 $.
Last updated $Date: 2002/05/02 22:02:58 $.