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V.22bis / V.22 / Bell 212 / V.23 / V.21 / Bell 103 Modem Software

V.22bis / V.22 Soft ModemV.22bis,V.22, Bell 212, V.23, V.21 and Bell 103 modem software is used for industrial applications. These libraries are modular and the software can be executed as a single task under a variety of operating systems or standalone with its own microkernel. Contact us to discuss your modem application requirements.

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VOCAL’s V.23, V.21, V.22bis,V.22, Bell 212 and Bell 103 modem software is optimized for performance on leading DSP architectures and processors from TI, Intel, ADI, ARM and other vendors. Our modem software  may be licensed standalone, as a library, or complete design. Custom solutions are also available.

Virtual Modem over IP

VOCAL’s SIP Software modem (MoIP or V.MoIP) solution provides developers a range of solutions to connect legacy dial up modems to modem infrastructure. Unlike other virtual modem designs, the SIP software modem can communicate with a physical modem at the far end using a VoIP service over an IP network.

Software Features

  • Fully compliant with ITU recommendations
  • Automatic modulation determination upon answer
  • Programmable ITU or Bell protocol selection for origination
  • Modem MIB support (RFC 1696)
  • Local and remote loopback diagnostics (V.54 and V.22 RDL)
  • Modular software suite available with controller code
  • Optimized for high performance on leading edge DSP architectures
  • Multi-tasking environment compatible

V.22bis / V.22 / Bell 212 / V.23 / V.21 / Bell 103 Modem

The line interface may be an analog front end (codec and DAA) or a digital interface such as T1/E1, Switched 56, and ISDN. The upper end of this software can provide a PPP, HDLC, V.14, or a direct binary framing layer. Higher data protocol layers, V.42 (including MNP 2-4), V.44, V.42bis and MNP 5, are options as well.

The V.22bis,V.22, Bell 212, V.23, V.21 and Bell 103  modulation family can be combined with other data modulations including V.92, V.90, V.34, and V.32bis,V.32. Automatic modulation detection procedures (Automode) include those of PN-2330, V.8 and V.8bis. All our data modulation software is fully compatible with VOCAL’s facsimile, telephony, speech coder and multimedia systems.


  • DAA interface using linear codec at 7.2 kHz, 8.0 kHz or 16.0 kHz sample rate
  • Direct interface to 8.0 kHz PCM data stream (A-law or μ-law)
  • PPP (RFC 1662), HDLC, V.14, asynchronous FSK, and direct binary framing layers
  • North American and International Dialing/Telephony dialing functions available
  • DTMF detection during voice modes available
  • Data protocol layer (V.42, MNP 2-4, V.44, V.42bis, and MNP 5) available
  • System can be combined with V.110 rate adaptation software
  • V.23/Bell 202 based Caller ID available
  • System can be combined with other modulations (V.92, V.90, V.34, V.32bis, et al) and automode procedures (PN-2330, V.8 and V.8bis)
  • Data/Facsimile/Voice Distinction upon startup is available.
  • Complete facsimile systems, modulations (V.34fax, V.17, et al.) and protocols (T.30), and speech coders available.
  • Multiple modulations can be executed on a single DSP



VOCAL’s optimized software is available for the following platforms. Please contact us for specific Bell 212, Bell 103, V.22bis,V.22, V.23, and V.21 data modem supported platforms.

Processors Operating Systems
  • Texas Instruments – C6000 (TMS320C62x, TMS320C64x, TMS320C645x, TMS320C66x, TMS320C67x), DaVinci, OMAP, C5000 (TMS320C54x, TMS320C55x)
  • Analog Devices – Blackfin, ADSP-21xx, TigerSHARC, SHARC
  • PowerPC
  • MIPS – MIPS32, MIPS64, MIPS4Kc
  • ARM – ARM7, ARM9, ARM9E, ARM10E, ARM11, StrongARM, ARM Cortex-A8, Cortex-M1
  • Intel / AMD – x86, x64 (both 32 and 64 bit modes)
  • Google Android
  • Apple iOS / iPhone / iPad & MacOS
  • Unix,  Linux, μClinux, BSD
  • Microsoft Windows ACM / RTC / CE / Mobile
  • Symbian
  • eCOS / eCOSPro
  • Wind River VxWorks
  • Green Hills Integrity
  • Micrium μCOS


Modem Datasheet

VOCAL Technologies, Ltd.
520 Lee Entrance, Suite 202
Amherst New York 14228
Phone: +1-716-688-4675
Fax: +1-716-639-0713