HYLAFAX 3.0 INFORMATION
[ HYLAFAX is the new name for FlexFAX; check here for the reason for the name change.]

This note describes the features and changes expected to be part of of HylaFAX Version 3.0. The software has been in production use for almost 6 months so it should be reasonably stable by the time of the first beta distribution. HylaFAX v3.0beta??? is expected to be available for public ftp in early February, 1995. As usual the announcement of its availability will be posted to the flexfax-announce@sgi.com mailing list (which is also fed to the flexfax@sgi.com list). Information on subscribing to these mailing lists is available here.


NEW FUNCTIONALITY

The following is an abbreviated list of new functionality that is to be part of the released version of HylaFAX 3.0. All items not marked as incomplete will be present in the first beta distribution.

Folks interested in defining a revised client-server protocol should contact me by electronic mail at sam@engr.sgi.com.


NEW SERVER ARCHITECTURE

HylaFAX 3.0 is a significant rearchitecture of the old FlexFAX software. Specifically, the server-side software has been redesigned to support:

The redesign splits the old faxd server process into three separate components: Send-only configurations can be implemented by not running the faxgetty program on ports where fax modems reside (though doing this can reduce the effectiveness of the load-balancing work done by the queuer). Receive-only configurations can be implemented by running only the faxgetty program on ports where fax modems reside.

High-volume transmission of facsimile is possible because of the improved central queueing agent and because outbound documents are imaged only as required by the capabilities of the receiving facsimile equipment. In addition the queueing agent supports priority-based scheduling of outbound jobs, so broadcast jobs can be scheduled ahead or behind other jobs simply be assigning or adjusting their transmit priority.

Effective load-balancing of modem equipment is done in the queuer by assigning modems according to transmit characteristics and the current status of each modem. faxgetty processes notify the central queuer when a modem is in use for inbound or outbound use and also communicate each modem's capabilities. This makes it possible for jobs to be scheduled so that they are not blocked waiting for modems to be available and so that the best modem for the job is assigned; e.g. if a fax receiver supports the V.17 high speed facsimile communication protocol, then the queuer will try to assign a modem that is capable of transmitting V.17 data. There are also provisions in the queuer for scheduling modems for non-fax use; however this functionality is not expected to be fully developed by the time of the 3.0 release. Future versions will be capable of doing optimal scheduling of modems for batch-oriented communication protocols such as UUCP.

The new queueing agent has extensive support for administrative control and monitoring of jobs. Jobs are scheduled using a priority assigned when the job is submitted. This priority permits administrators to run important jobs ahead of less-important jobs such as broadcasts. Per-destination parameters can be defined to control:

The configuration database is designed so that parameters can easily be applied to groups of destinations with a single specification and yet have a parameter for a single destination ``override'' a previous group-oriented definition. Optimizing phone usage by scheduling long distance calls to off-peak hours, for example, is simple with the new controls. Likewise disallowing outbound jobs to sensitive phone numbers (such as 911) is also easy.

Because the faxgetty process is not required for a send-only configuration, the HylaFAX software can be more easily configured for use on systems that support bidirectional modem use through device pairs (one device for outbound use and one for inbound use). Similarly, the faxq program can be combined with other ``Smart Getty'' software, albeit with some loss in effectiveness of load-balancing algorithms implemented in the central queuer process.


NOTEWORTHY CHANGES

The following is an abbreviated list of the changes between the last public distribution of FlexFAX, v2.3beta036special, and the first beta distribution of HylaFAX 3.0.


DISTRIBUTION PLANS

HylaFAX will be distributed in source and binary form by public ftp on the Internet. Full binary distributions for all ``supported platforms'' are intended to be available at the same time as the source distribution. Source distributions that are built with the GNU gcc compiler must use gcc version 2.6.1 or later. As noted above, availability of distributions will be posted to the flexfax-announce and flexfax mailing lists.

(TOC) HylaFAX table of contents.


Sam Leffler / sam@engr.sgi.com. Last updated: $Date: 1998/10/12 20:47:51 $