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Modem Requirements

If you want to fax via a VoIP line (Voice over IP), the T.38 protocol (Fax over IP) must be activated in the router. Otherwise, faxing is hardly possible!
I receive a lot of email about this. Sorry.


Sending faxes should work with any modem. For fax receiption you will need a modem which supports Fax Class 2 or 2.0.
For the Voice functions CoMa needs an Voice capable modem (Class 8), which understands either IS-101-Standard- or Rockwell-instructions.
If your modem is not listed in the Table, try the setting 'IS-101-Command-Set' or ' Rockwell Command-Set'.
If you have a voice-modem which doesn´t work with any setting please contact me.
You can connect voice modems with a serial interface to a USB-Mac by using a USB-Serial Adapter.
Many USB-Serial-Adapters provide no Mac driver, but may work with the driver from Prolific.
Some of the modems tested are no longer available, but are still available used.

Overview of the possible CoMa functions with the tested modems:

Modem Type12 3 4 5 6 7 8 9 10 111213 14 15 16
Fax Class 1Fax Class 2Fax Class 2.0DrayTek mini VigorStd Rock wellMicro Link ISDNLasat unique 1280miStd IS-101Zoom 2986Micro Link OfficeDr. Neu hausZyXEL Elite IDZyXEL EliteZyXEL 1496USR Pro MessageUSR Sportster
Answering machine XXXXXXX XXXXXX
Different announcements for called IDs or for different callers?XX? XX
Display of the caller (CLIP)????XX? XX
Display of feesX X
Voice-On-Demand with DTMF-codes X X X X X X X X X X X X X
Forwarding of messages X X X X X X X X X X X X X
Voice-Jobs X X X X X X X X X X X X X
Dial Voice number - > take over to telephone? ????XXXXXXX
Record via Mac microphone X X X X X X X X X X X
Convert AIFFs <-> Modem format X X X X X X X X X X X
Monitoring during recoding of a caller X X X X X X XXX X X XX
Send FaxesX X X X X X X X X X X X X X X X
Receive FaxesXX XXX? X X X X X X X X
Poll Faxes? X X X X?X X X X X X
Let poll Faxes ?X XXX?X X X X X X
Fax-On-Demand with DTMF codes X X X X X X X X X X X X
Answering machine with switched off Mac X X
Receive Faxes with switched off Mac X XX
USB interface???X??X
ISDN???X?XX?X

***************** Fax Modems **********************

1) Modems, which support only the old Fax Class 1
Also all current internal Apple modems
The WebShuttle driver 1.2 does not work with OS 10.3.6. The old driver 1.1 works.

2) Modems, which support Fax Class 2
Also the older internal Apple modems

3) Modems, which support Fax Class 2.0

******* ISDN TA with Bit-Transarent-Mode **********

4) DrayTek miniVigor
This TA supports Fax Class 1 with maximally 9600 bps. Therefore CoMa can only send faxes.
There are all Voice functions possible, even better than with Voice modems. The ID of the caller as well as the called ID cannot be queried with miniVigor unfortunately.

***** Voice Modem with Rockwell-Command-Set *****

5) Modem with Rockwell chip
There are very many modems with Rockwell-Chip. The following were tested:

Elsa MicroLink 28,8 TQV
TKR tri star
kik by Wildner
Creatix LC144 VF

6) Elsa MicroLink ISDN/TL V.34

7) Lasat unique 1280mi

***** Voice Modem with IS-101-Command-Set *****

8) Modems with the Standard IS-101-Command-Set
There are very many modems with the Standard IS-101-Command-Set. The following were tested:

8a) Motorola SM56 SoftModem (internal)
This "Voice modem" has unfortunately some weaknesses:
- The speech quality is bad (< 40 dB)
- During the announcements no DTMF tones are recognized
- During recording sometimes wrong DTMF tones are recognized
- Redirection of incoming voice calls / Voice jobs does not work always reliably

9) Longshine LCS-8156C1 / Zoom 56k USB model 2986 / Elsa MicroLink USB

10) Elsa MicroLink Office with independent Mode

11) Dr. Neuhaus Cybermod 28.8/33.6 & SMARTY (R) 19,2 TI DNE 1126V V.0.00.0662 Voice

***** ZyXEL Voice Modem *****

12) ZyXEL Elite 2864 ID

13) ZyXEL Elite

14) ZyXEL 1496

***** US Robotics Voice Modem *****

15) USR (pro) Message (plus) with independent Mode
- it cannot be determined whether a fax was received with 100 or 200 dpi
- time is forgotten when switching off

16) Sportster Vi/Sportster Flash 56000