PowerFax for OTF

PowerFax for OTFOTF, Commetrex’ S.100 middleware, is licensed without media-processing resources. PowerFax® for OTF adds Group 3 fax send and receive capability to an OTF system. The PowerFax OTF SDK provides the necessary development environment; runtime licenses add a specific number of runtime resources to an OTF system. These runtime resources can be for any MSP-series resource hardware or for PowerFax TerminatingT38, which supports fax send-receive in real time over IP networks.

The PowerFax for OTF SDK includes an ECTF S.100 Fax Sender-Receiver API. It is used with the System Call Router (place call/accept call) and other OTF Services APIs to develop digital-media fax applications. The SDK includes Commetrex’ acclaimed T.30 fax protocol engine. The call-specific send-receive resource—analog modems or terminating T.38—is determined on a per-call basis without direct involvement by the application. The resource may be TerminatingT38 if the call stream terminates on an IP network, or the MSP product family, if it terminates on the PSTN. This means the fax application can be developed without regard to the type of network or resource board to be used on a given call.


  • PSTN and IP with the same API
  • V.21, V.27ter, V.29, V.34 and V.17 analog fax modems
  • Commetrex Fax Description language (FDL)
  • Comprehensive header-footer facility
  • Maximum-Concurrent Port Licensing
  • Dynamic document re-sizing and re-encoding
  • S.100 application portability
  • C-language demo programs
  • Unlimited technical support
  • Ultra-high density


  • Reduced development costs
  • Reduced inventory costs
  • Reduced support costs
  • Reduced per-channel costs
  • Comprehensive technical support and demo programs speed system development


OTF is an ECTF S.100 R2-conforming telephony middleware product that supports both third-party and Commetrex-provided media and switching resources. These vendor- specific resources are isolated from the OTF system by Resource Service Managers (RSMs). The resource-specific RSM determines the number of concurrent media- technology resources that have been licensed. The RSM then launches the appropriate Resource Controllers. Licensing the PowerFax SDK adds the Fax Sender-Receiver Resource Controller to an OTF system. The RSM will then vend the licensed runtime resources to the OTF Group Manager, which can then allocate them to client applications.


The PowerFax API provides the following send functions:

  • CTfaxsd_Send() This function transmits facsimile data from a Spatial Media (SM) using a Fax Sender resource.
  • CTfaxsd_Resume() This function resumes a Send operation that was previously placed in a Ready state.
  • The Ctfaxsd_send() function takes a list of one or more Spatial Media (SM) objects (TIFF-F files) as an argument. Each SM object can be single or multi-page. The client may optionally enable the generation of events at the end of the T.30 negotiation phase (phase B) and at the end of each page (phase D). The client may optionally place the Fax Sender into Ready Mode to enable receipt of the FaxReceiver_ECTF_Start (RTC) action by setting the FaxSender_ECTF_StartReady parameter to CTbool_False or by not setting the parameter.

The API provides the following receive-related functions:

  • CTfaxrv_Receive() This function receives facsimile data and stores them in the specified SM Object using a Fax Receiver resource.
  • CTfaxrv_Resume() This function resumes a Receive operation that was previously placed in a Ready state.
  • Ctfaxsd_Send() receives facsimile data and stores them in the specified SM. If more than one page is received, it is stored in a single SM. The client may optionally enable the generation of events at the end of the T.30 negotiation phase (phase B) and at the end of each page (phase D). The client may optionally place the Fax Receiver into FaxReceiver_ECTF_Ready state to enable receipt of a FaxReceiver_ECTF_Start (RTC) action by setting the FaxReceiver_ECTF_StartReady parameter to CTbool_True.

Headers and Footers

PowerFax offers three options for placement of a header or footer on a fax page:

  • Overlay: the header or footer image is overlaid on the page;
  • Replace: the image data in the page at the header or footer location is replaced by the header or footer image;
  • Insert: the header image is inserted before the page image, or the footer is inserted after the page image.

The contents of an extended header or footer can be specified by using the fax parameters FaxSender_ECTF_HeaderField and FaxSender_ECTF_FooterField. These extended headers and footers may be customized by setting values for replaceable parameters within the Headerfield or Footerfield string. The replaceable parameters are specified using Unicode characters and escape sequences, consisting of the Unicode character ‘%’, followed by a format code. The resource substitutes a character string for the escape sequence as specified in table below.

Parameter Codes Display Length Name Range
%d 2 date 01-31
%m 2 month 01-12
%y 2 year 00-99
%Y 4 year 0000-9999
%I 2 12 hour 01-12
%H 2 24 hour 00-23
%M 2 minute 00-59
%S 2 Second 00-59
%p 2 AM/PM AM or PM
%P 3 page number 01-999
%l 20 Local ID 0-9, + or SPACES
%r 20 Remote ID 0-9, + or SPACES
%% 1 percent display % in header

MultiFax FDL

MultiFax Fax Description Language (FDL) macros support the creation of fax-image files (SM files) from dynamically assembled elements. For example, a personalized fax letter including information obtained from a centralized database, a pre-scanned signature, the date, time, and even a per-call personalized paragraph, can be created and transmitted in seconds. Examples of FDL macros are:

These macros are inserted into a text file and converted using the MultiFax file- and format- conversion functions. The resulting file is then placed in the appropriate SM container.

Format Conversions

The files produced by word processing, page layout, and graphics packages are generally not in the file format a fax transmits and receives. PowerFax supports conversions from FDL, PCX, Bi-Level TIFF, TIFF-F, and text (including Windows NT outline fonts).

Developer Support

PowerFax includes unlimited technical support. And, at Commetrex, this is top-level support. Our support engineers are development engineers themselves, experienced in developing in-house applications using the same Commetrex products our customers use. They are experts in not only the specifics of PowerFax, but with digital-media telephony, and fax environments as well.


FAX ENCODING: MH, MR and MMR. Error Correction Mode (ECM)
SEND-RECEIVE RESOURCES: Terminating T.38, V.21 (300bps) for T.30 negotiation, V.27ter (2400/4800bps), V.29 fax (7200/9600bps), V.17 fax (14400/12000/9600/7200bps)

Configuration Information

PowerVox adds terminating voice to an OTF-based system. All members of the MSP line of DSP-resource boards are supported, as is the all-IP BladeWare IP media server.
OTF for MSP SDK, PN 20070
OTF PowerFax SDK, PN 20030
OTF PowerCall SDK, PN 20050
OTF PowerVox SDK, PN 20060
PowerVox Runtime License, PN 50006