VoIP and Faxing

With VoIP technology (Voice over Internet Protocol) advancement, demand for the adoption of IP telephony grows more and more. It is no secret that VoIP offers a great more deal of advantages over traditional telephony, let alone the far cheaper prices.

Faxing has not grown obsolete. It is still a reliable and swift way to transmit all sorts of business-critical information like legal documents, contracts, order confirmations, etc. Besides, the need of signed hardcopies makes faxes for legal reasons compulsory for any business.

What VoIP could not offer as well as traditional landline telephony was faxing. Faxing over VoIP is practically impossible for one simple reason: VoIP telephony cheapness is achieved through compression of signals for the sake of making more calls with less bandwidth. This means that voice data gets compressed to travel to the other side, where it gets decompressed. This is performed by codecs.

Faxing with VoIP

While compression is achievable with voice, faxing is quite different. Actually a fax modem is converting an image (e.g. a document, picture, etc.) into an analogue signal, and modulates it over an appropriate carrier frequency of the sound spectrum. The signal travels through landlines to reach the other fax modem that actually recognizes the fax signal, demodulates it and converts it back to an image.

So here is the big problem. Compression means some loss in signal spectrum, phase and amplitude. There is no way this loss to be recovered. So a somewhat damaged or modified signal reaches the receiving modem. No device or algorithms can convert a compressed signal the way it was before compression. Otherwise there would have never been any problem with broadband requirements or disk space availability.

This is why faxing over almost can VoIP never work properly and if it does “work”, it behaves quite unpredictably, and the result images are often unrecognisable. VoIP is based on compression for the sake of broadband while faxing is based on a nearly perfect conversion of images.

Our FoIP (Fax over Internet Protocol) solution is based on the following mechanism: a fax terminal passes analogue data to a T.38 gateway. The gateway takes the signal, demodulates it and transmits it over the existing IP network to another T.38 capable device (e.g. Internet Aware Fax(IAF) or a compatible Analogue Telephone Adapter (ATA)) or another T.38 gateway that modulates back the digital signal and sends it over the PSTN to another fax terminal.

The sensational part of our T.38 solution is that it is actually a far more reliable faxing method than traditional analogue faxing. This is not a phenomenon; it is due to the fact, we may want to believe that landlines are good carriers, but this is far from true as far as greater distances are concerned. IP networks are more reliable carriers over long distances and with our FoIP solution, you will inevitably enjoy faxing more than ever!

• T30faxRX for receiving normal faxes over PSTN
  
  
• T30faxTX for transmitting normal faxes over PSTN
  
  
• T38faxTX for T.38 fax origination (IAF fax)
  
  
• T38faxRX for T.38 fax termination (IAF fax)
  
  
• T38gate for FoIP gatewaying

The coalescence of your IP-network with fax technology will incontrovertibly leverage your ROI.
FoIP is nowadays obtainable in different forms leaving you the prospect of using different sending devices, such as IAF (Internet Aware Fax, or smart faxes), dumb faxes and mail clients.

• It is fully compliant with the T.38 standard
  
  
• It supports the following ITU-T modems: V.27ter, V.29 and V.17 with speeds of up to 14400 bps!