How Does Fax Over IP Work?



The T.30 fax protocol was designed for use over analog phone lines. In order for fax to work reliably over the Internet the analog signal used by fax machines must be converted into digital packets in a way that provides real-time fax transmission with very little data loss and delay. Since Voice over IP (VoIP) is optimized for voice calls by using compression to reduce the amount of bandwidth required, it is not suitable for faxing. Thus the T.38 protocol was created to provide reliable real-time faxing over IP (FoIP).


The How Does Fax Over IP Work? white paper briefly describes the T.30 and T.38 protocols, which enable fax to be sent over an IP network. It then describes how these protocols work in a Fax over IP (FoIP) implementation by comparing traditional fax technology with the more advanced fax option of sending faxes over an IP infrastructure.


Find out more by downloading the white paper.


Dialogic inspires the world’s leading service providers and application developers to elevate the performance of media-rich communications across the most advanced networks. Its time-tested industry-leading fax technology, delivers a broad range of fax and fax over IP (FoIP) products, which are supported by more than 60 software partners worldwide (as of 2015).