PowerFax® for BladeWare™ gives the BladeWare user the media resources to support both PSTN and SIP-based IP fax from the same application and at the same time. Commetrex’ MSP™ PSTN interfaces include 2-24-port PCI and PCI Express (PCIe) analog boards supporting inter-mixed station and office trunks; digital support includes ISDN PRI and BRI with single-, dual-, and quad-span boards. Real-time IP fax includes Commetrex’ category-defining TerminatingT38 Version 3 with optional V.34 and G.711 pass-through fax with optional V.34 support. BladeWare supports SIP for IP signaling. PowerFax also supports Commetrex’ exclusive Smart FoIP, which yields the industry’s highest FoIP transaction success rates.

Smart FoIPThe PowerFax SDK is used to develop fax applications, such as enterprise fax servers and fax media servers for hosted-fax applications. The PowerFax SDK includes Commetrex’ acclaimed T.30 fax protocol engine and fax modems. The specific send-receive resource—analog modems or terminating T.38—that will be used on a call is automatically determined by BladeWare on a per-call basis without direct involvement by the application, so you need only write your application once, without concern for the network or fax transport that will be used on a call. The resource may be TerminatingT38 or G.711 pass-through, for example, if the call stream terminates on an IP network, or the MSP PSTN TDM interface, if it terminates on the PSTN.




BladeWare is an open HMP telephony platform that supports both third-party and Commetrex-provided media and call-control resources. These resources are added to a BladeWare system by adding their respective Resource Service Managers (RSMs), which normalize network-interfaces and signaling to the balance of the BladeWare system. Licensing the PowerFax SDK adds the Fax Sender-Receiver RSM to a BladeWare system. Other RSMs include the MSP RSM for PSTN boards, the SIP RSM for IP signaling, and the Voice Play-Record RSM when voice support is required.

Client applications access this functionality through an integrated API.

PowerFax Send-Receive Resources

PowerFax for BladeWare offers the industry’s broadest choice of fax send-receive resources, all of which are transparent to the fax application, and all of which are based on Commetrex’ industry-best fax technologies:


The MSP-FX S/OPCM interface is a half-height-size PCI or PCI Express board with 2-, 4-, 6-to-24 ports using one expansion-card slot. Each card has either two or four ports, depending on the number of two-port daughter cards included. The daughter-cards can be either station or office-trunk interfaces in any combination. Expansion is accomplished by interconnecting up to six boards via a micro-backplane connector. Additional power for configurations beyond 8 ports or station-trunk interfaces require that the host PC’s 12 volt power supply be connected via a standard power cable. Since all 24 ports are part of the same assembly, all ports operate on the same PCM clock.

The MSP product line also includes support for ISDN BRI in 2-, 4-, 6-to-24-port configurations.



The MSP-E/T PCI and PCI Express digital PSTN-interface boards offer single-, dual-, and quad-span E1/T1 interfaces supporting systems with up to 120 fax ports in a single PCI or PCIe expansion slot. Both robbed-bit and common-channel signaling, including ISDN EuroPRI, are supported.


Commetrex invented TerminatingT38in 2000, yielding an unequalled field history resulting in unmatched interoperability. TerminatingT38 is a special integration of Commetrex’ ITU T.38 and T.30 fax protocol engines, giving the developer of a network-service platform or an enterprise fax server the system resources necessary to terminate T.38 (IP network) real-time fax transmissions the same as it would real-time faxes from the PSTN using the PowerFax analog modems with the MSP boards.

Robustly transporting a fax that originates in a ‘traditional’ fax terminal over a packet network to a traditional receiving terminal in real time requires that a fax-relay entity be situated between each terminal and the packet network. These entities—the relays—must render the delays and timing uncertainties of the packet network transparent to the T.30 protocol engines operating at the transmitting and receiving terminals.

Commetrex has developed a version of its T.38 Fax Relay gateway product that, rather than relaying the fax to the PSTN, terminates the fax in TerminatingT38’s server-based T.30 protocol engine. One of the legacy fax terminals is removed and Commetrex’ TerminatingT38 substituted so that the fax terminates in the service platform rather than a fax terminal.

PowerFax T.38 (and MMTF, see below) support T.38 Version 3 with V.34.


Multi-Modal Terminating Fax

Multi-Modal Terminating Fax (MMTF) is an integration of Commetrex’ T.30, T.38, and host-based analog fax modems to create a system that allows a media server to terminate faxes from PSTN-IP gateways supporting either T.38 or G.711 pass-through for fax transmissions, as shown below.

Headers and Footers

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

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 CodesDisplay LengthNameRange
%I212 hour01-12
%H224 hour00-23
%p2AM/PMAM or PM
%P3page number01-999
%l20Local ID0-9, + or SPACES
%r20Remote ID0-9, + or SPACES
%%1percent display% in header

PowerFax FDL

PowerFax 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 PowerFax 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).


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 (7200/9600bps), V.17 (14400/12000/9600/7200bps),V.34 (up to 33.6Kbps)

FoIP Interoperability

T.38 Interop LabCommetrex has led the industry effort for T.38 interoperability since January 2002, when it launched the T.38 Interoperability Test Lab. Recently, Commetrex has done extensive interoperability testing with the BladeWare HMP telephony platform, with international carriers, service providers, and enterprises.

Related Publications

Configuration Information

PowerFax adds terminating fax to BladeWare. All members of the MSP line of PSTN-interface boards are supported, as is the all-IP BladeWare IP media server.