Without fail every time I present to an audience I am confronted with the question, "How do you handle Faxing?" Faxing is the bane of IP Communications. Industry numbers indicate a one-page fax failure rate of around 80% with multiple page faxes failing more often. At Broadvox, we have worked hard to improve upon the numbers. We are better than 80% successful delivery of multiple page faxes. I do not know our number for single page faxes but would guess it to be better than 90%. However, while that is good enough to support the cancellation of POTS lines being used for fax for most businesses. It is not good enough for a company where faxing is a major element of their business. So what to do? We have assigned solving/improving our fax performance to one of our lead SIP engineers and he has accomplished much. However, the industry needs to address this problem before it will be considered solved.
Today, the SIP Forum is beginning to address Fax-over-IP (FoIP). This is important as it could help smooth out some of our open interoperability issues with various IP PBX vendors. By way of example, most support faxing over T.38 but others want to use G.711. This difference presents a problem in and of itself. Moreover, some ITSPs do not support T.38 at all and pass fax traffic using G.711. Yes, it is time for the SIP Forum to sit down and address the reliability and quality of FoIP.
To learn more about what the SIP Forum and activates related to FoIP interoperability visit http://www.sipforum.org.