Third party software
When electronic documents are faxed via a network fax server, the
document that is received on the destination fax machine should look the same as the
original document. While most fax servers provide a "What You See is What You
Get" or a "What You Print is What You Get" feature, in reality some
products are more successful in delivering on this promise than others. This is because
the method of document conversion used by different fax server products varies greatly.
The way in which a fax server product converts documents from native format to fax image
format has an impact in the following areas:
Scope of document formats handled: How many different
document formats can the fax server application handle and convert successfully to a fax
Throughput: How does the fax servers document
conversion process impact the performance of the server to send and receive faxes?
- Quality of Reproduction: The appearance of the fax image and
its faithfulness to the original document.
Before a fax server can send a document, it must convert it from its
native format to a standard bitmap image format Group 3 TIFF format. Either the
document is converted by the client desktop computer and then sent to the fax server, or
sent to the fax server in its native format and then converted to an image at that point.
Documents can be converted on the client desktop when software to do this conversion has
been installed on the desktop. There are various options to initiate this client-based
- "Print-to-Fax" within any desktop application.
- "Print-to-Fax" within any desktop application, using a Web
- "Print-to-Mail" within any desktop application.
In all cases, when the fax client, e-mail client, or Web browser
pops up, the document has already been converted on the client from its native file format
to a faxable image format.
There are two approaches that are commonly taken for converting documents on the client
desktop. In either method, the end-goal is to convert the document into the TIFF format
that is used by most fax modems and fax boards. Many fax servers convert the document to
an intermediate format a PCL image and then let the fax server finish the
conversion to a TIFF image. Most fax servers have selected this method because it is easy
to create a PCL conversion driver to be used within desktop applications. PCL converters
are a slight variant of the standard print drivers provided by Microsoft. The problem with
this two-step conversion is that it creates a performance bottleneck on the fax server
because it must now convert all its documents from PCL to TIFF before sending them out.
For small LAN fax servers with a handful of telephone lines, the bottleneck caused may not
be significant. However, in a high volume enterprise server it may be critical to not have
the fax server responsible for this extra step. A one-step conversion model, as used by
Omtools Fax Sr., avoids the need for this extra step and as a result, reduces the
processing load on the fax server.
Fax servers should support both these methods of document conversion, as there are times
when it is important that the faxed document appears exactly as it would appear on a
printer What You Print is What You Get. Certain printer specific formatting can
take place while converting a document from its native format to a PCL or Postscript
image. Converting the document directly to a TIFF image would not take into account any
printer-specific formatting commands.
There are many cases in which converting the document to a faxable image on the client is
either not desirable or not possible at all:
- The user sends a fax and specifies that the fax should consist of
multiple attached documents. Since each of the documents was simply attached to a message,
there is no opportunity to run the documents through the print to image converter on the
- To minimise the number of software applications being supported,
corporate standards may prohibit fax client software from being installed on each
- When faxes are submitted to the fax server from other back-office
business applications using the fax servers API. In this case no client is involved
in the definition and creating of the fax, so converting the document to an image on the
client is not possible.
Fax servers should provide a comprehensive approach to document
processing on the server to give the system manager a choice of conversion via third party
software or by OLE or DDE communication with the application software.
Third party software
Third party document conversion software is a popular option but can have limitations. The
conversion filters may not handle every commonly used document type; they might not
convert the document as perfectly as the application that created the document; and the
version of the desktop application that they support may trail the latest release of the
desktop application. However, they are simple to configure and usually produce acceptable
results. If the quality of the third party conversion for a specific desktop application
format is not satisfactory, the fax servers OLE or DDE interface to the original
application can be used to convert the document to an image. The OLE interface is easily
expandable, and has been created for the most popular software, including the three most
popular office suites.
If the application cannot be communicated with via OLE, you can still use the fax
servers DDE interface to instruct the application to generate a print image that can
be faxed. Connection using an OLE or DDE interface will consistently give accurate
In conclusion, the most important features of the document conversion system employed by a
fax server product are the ability to:
- produce a quality fax image
- handle all possible formats of documents
- optimise system resources so as to eliminate processing bottlenecks
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