Communication devices (TAPI or DIVA)

INS supports any TAPI compliant voice modem or voice boards for its voice features.
Please click here for more information on using INS with SIP VoIP.
Please click here for more information on using INS directly with PABX (phone systems).


Voice devices

What is a voice board ?
A voice (or telephony) board is a device designed specifically for doing voice processing over telephone lines. Telephony cards provide much better quality audio output than voice modems and may support multiple phone lines on a single card. The most common brand for professional telephony boards is Dialogic.
A TAPI telephony card is one that works with the Windows Telephony API. INS supports either the native Dialogic API or the Windows TAPI API.
In order for a TAPI telephony card to work with INS, it must provide support for playback and recording of wave format audio.  Technically, that means the device must provide TAPI "wave/in" and "wave/out" devices.

Due to the increased reliability and better voice quality, we recommend the use of a voice board over a voice modem.

What is a Windows voice modem?
A voice modem is a modem that is capable of playing and recording audio over a telephone line.  While almost all modems are capable of doing data and fax, a growing number have voice capabilities.  Modern voice modems are powerful telephony devices capable of advanced features like voice interaction, call transfers, and outbound dialing.  For most users, a high quality voice modem and advanced telephony software like INS will allow them to create a professional communications solution.  Common brands include US Robotics, 3Com, ZOOM, ModemBlaster, EigerMedia, and others.

In order for a voice modem to work with Windows TAPI, the modem must have voice drivers and sound devices. Sound devices (or Wave Devices) for the voice modem are usually provided by the manufacturer.  You need to make sure that you configure your modem with the latest modem driver. Unfortunately modem suppliers still seem to sell their modems with outdated drivers, which often do not support Voice & CallerID. The only way to be sure that you have the right driver is to download the newest driver from the Internet. You may even need to experiment with different drivers.
IE the 3COM U.S.Robotics 56K Message Modem does not support Caller ID with its own driver (U.S.Robotics 56K Message) but detects CallerID with the U.S.Robotics 56K Voice EXT driver.

Voice boards
(For best results, we recommend Dialogic Diva telephony cards to be used with INS)
Can be used with normal analog phone lines and T1 and E1 lines

Telephony cards are a much better solution than voice modems, offering better quality sound playback/recording and better detection of DTMF and busy tones.

Dialogic Diva cards listed below can be used with INS.

Analog cards ISDN cards

Good entry-level cards for analog phone lines are the 4 port Diva Analog-2, they costs around US$600.

Dialogic cards can be purchased from:
Used cards: Ebay (, or
  Europe: (Search for DIVA)

A driver CD should be shipped with the cards. The free Dialogic® Diva® System Release 8.5WIN driver can also be downloaded from:  (47MB)

Please also see: Installing a Dialogic DIVA Systems.


Please note for the following (older) Dialogic cards:
D/4PCI, D/4PCIU, D/4PCIUF, D/41E, D/41EPCI, D/41JCT, D/41ESC, D/41H, D/42 series, D/120JCT,  D/160S, D/21H, ProLine/2V, D/21D, D/41D, Dialog/2, Dialog/4, all digital T1/E1 cards: D/240, D/480, D/300, D/600, and all DMV-series cards.

Those cards are now not supported anymore as the necessary SR does not support TAPI. If you find a "old" card you may still use it on an Windows-XP systems. Please click here for the installation guide.




Can be used with analog phone lines only


The range of telephony boards supplied by AltoEdge is in general cheaper than the Dialogic boards. We found them however also less reliable and sometimes quite tricky to install.
They may however be well suited for simple applications that only need a reduced amount of channels.


AltoEdge Professional PCI Telephony TAPI Board

Available in 2, 4 or 8 lines per board
These multiple line telephony cards are suitable for Interactive Voice Response (IVR), Voice Mail, Automated Attendant, Telephone Dictation and other telephony applications.
  • 2, 4 or 8 independent voice processing ports supporting low-to medium-density voice systems in a single PC
  • u-law voice coding with selectable data rates 32 Kb/s or 64 Kb/s on a channel-by-channel basis
  • Configure multiple boards in a single PC for easy and cost-effective system expansion, capable of scaling from 2 to 16 ports
  • Caller ID detection, supports FSK as well as DTMF
  • Full duplex voice channels
  • Bundled with TAPI and wave drivers for Windows 2000 and Windows XP
  • Support LC Drop/Polarity Reversal detection
  • Detailed call progress monitoring & analysis
  • Up to 4 boards can be installed in the same PC.
  • Professional quality card for business applications.
  • Easy to install with plug-and-play operation.
  • Approved by FCC (USA), CE (Europe) and others.




System Requirements
  • Windows XP / 2003 / Vista / 7 (32-bit versions only - 64-bit operating systems are not supported)
  • Free PCI bus slot **
  • Analog telephone ports. (Two RJ-14 jacks).
  • VL2 and VL4 require a 3.3V PCI slot. **

** Over the past few years there have been a number of variants of PCI slots. The 2 line and 4 line cards (VL2 and VL4) need PCI slots that have 3.3V (PCI 2.2). If you are in doubt check the manual of your computer motherboard to see if it is a "PCI bus 2.2". You will be confident all cards work if you know your PCI slots have both 3.3 and 5V supplies. By far the majority of modern computers have this but it is worth checking the motherboard manual.

Telephone Interface
  • Line interface: Loop-start
  • Connectors: 2, 4 or 8 RJ-14 jacks
  • Return loss: 20 dB min (300 to 3300 Hz at 600 Ohms impedance)
  • Caller ID: International capability via on-hook audio path
  • Sample rate: 8KHz
  • DTMF digits: 0 to 9, *, #, A, B, C & D 40ms min.

Order 2 line board from AltoEdge
(You will be redirected to the AltoEdge order page)


Order 4 line board from AltoEdge
(You will be redirected to the AltoEdge order page)


Order 8 line board from AltoEdge
(You will be redirected to the AltoEdge order page)

  TELCURLVL2 (USD$399.00)   TELCURLVL4 (USD$549.00)   TELCURLVL8 (USD$1049.00)  



  Other Telephony Cards
Can be used with analog phone lines only
CallUrl Voice 2/4 LV+ 2- and 4-Port Analog Interface Voice Board
The Voice 2/4LV+ provides two/four telephone line interface circuits for direct connection to analog loop start lines. Up to 4 Voice boards can be installed in a single PC chassis enabling port expansion up to 16 ports per system.
Data Sheet
CallUrl Voice 8LV 8-Port Analog Interface Voice Board
The Voice 4/8LV provides four/eight telephone line interface circuits for direct connection to analog loop start lines. Multiple Voice boards can be installed in a single PC chassis enabling port expansion up to 80 ports per system.
Data Sheet
Other manufactures : Ai-Logix (formerly Music Telecom) and Natural Micro Systems no longer provide TAPI drivers for their products, hence cards from those manufacturers cannot be used with INS.
  CAPI Cards
Can be used with BRI ISDN lines and T1/E1 ISDN lines
INS can be used with any ISDN BRI (2 channel 128Kbs) and ISDN PRI (24 channel T1 or 30 channel E1) cards that supports CAPI. This includes cards from:
Dialogic Communication Solutions (formerly EICON) (BRI-2M, 4BRI-8M, etc)
AVM (Fritz!Card, B1, C2, C4, T1, Fritz!GSM, etc)
BT Speedway (UK version of the AVM Fritz!Card)
PrimuX cards from Gerdes AG
and many more, see here.
Please also see: Installing on CAPI / ISDN Systems.
  Telephony Devices
Can be used with analog phone lines only

  Mediaphonics Phonerider USB

This one line device has high quality playback and recording, together with good DTMF tone detection. The Mediaphonics company has now closed down but there are still a number of distributors holding stock of this device. One place to get them from is (priced at around US$200).

  Way2Call's Hi-Phone DeskTop

This one line device has high quality playback and recording, together with good DTMF tone detection (priced at around US$200).

  Modems (Voice capable)
Can be used with normal analog phone lines only
In general external modems work a lot better then the internal modems, and internal 'Soft' modems have a number of issues. We do not recommend using internal modems in general.

As the modem models on the market change frequently we cannot provide a definitive list of current 'best' modems. We have found that the quality of sound playback and recording can vary between different releases of the same modem. When selecting your voice modem we recommend trying a few modems if possible and choosing the best one. For help on choosing the current best modem its probably best to ask for some help at a large computer shop in your local area. They will be able to advise which modems can correctly recognize your local telephone company's CallerID signaling, and which have a good reputation for sound quality. A discussion thread on which modems other users have found satisfactory is running on the INS Support Forum.

Many voice modems have one or more of the following problems:

  Poor sound quality/volume.
  Unreliable DTMF tone detection.
  Cannot do call transfers as hookflash length is too long or too short.
  Mistakenly detect a disconnect tone while playing or recording messages and hangup a call halfway through playing/recording of sound file.
  Unable to interrupt the playing of a sound file halfway through.

For reasons above many people find voice modems unsuitable and choose to use a telephony card instead (Dialogic).

For a feedback from users about the different modems click here.

For a detailed list of modems we tested with INS please click here.

For a detailed list of modem drivers under Windows 2000/XP please click here.

Our recommendation for a voice modem is the US Robotics 56k Message Modem V.92


Installing Voice Modems

When using a voice modem the first thing that should be checked is whether it's Wave drivers have been correctly installed. Without it's wave drivers the modem will not be able to play and record sound files. To check that the wave drivers are installed you will need to view the Windows Device Driver Manager.

Windows 7/8/10
  1. Open the Windows Control Panel
  2. Double click on the System Icon
  3. Click the Hardware TAB and Device Manager button
  4. Click the + next to Sound, video and game controllers.

Check if the "UniModem Half-Duplex Audio Device" driver appears.

If the wave drivers have not been installed for your voice modem then you should update or reinstall your modem drivers. You should also double check if the modem does in fact support voice (note: many 'speakerphone' modems do not support 'voice').

If its hard to find a Voice modem in your local area you can try buying them online from these places:


Note: Modems using the UnimodemV TelephonyService Provider (TSP) can only work with PCM 8000 Hz, 16 bit Mono wavefiles.  Other more sophisticated telephony devices can play other formats that allow for greater compression. In essence TAPI has nothing to do with the Wave files, the Windows Media Control Interface is used to play and record to/from the media device which just so happens to be part of the modem.
If you are looking for an inexpensive program to work and convert wave files look at Cool Edit,

  Other Miscellaneous Add-Ons
Instead of plugging analog telephone lines into the Dialogic card (or voice modem) you can just attach the Fixed Cellular Terminal device and receive & make calls over the GSM mobile network. Very useful solution in situations where:
It may take some time for the lines to be installed,
You need to move the IVR system frequently,
You need to change the phone numbers used by the IVR frequently (just purchase different pre-paid SIM cards),
You need to place many calls to mobile phone numbers (mobile-to-mobile calls are usually cheaper then landline-to-mobile calls),

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