Businesses are increasingly deploying Voice over IP (VoIP) as the standard enterprise voice solution. VoIP enables businesses to consolidate their voice service over a common data infrastructure, streamline administrative staff, and reduce communications costs. The leading PBX manufacturers such as Avaya, Nortel, Cisco, Siemens, and Alcatel are all investing heavily in developing VoIP equipment.

At the same time, a well-worn legacy technology known as "fax", with roots to 19th century telegraphy, refuses to go away. Fax remains the standard "quick and dirty" tool for exchanging business and personal information, especially between parties that do not frequently work together. Healthcare, legal, government, hospitality, finance, education, and real estate are among the numerous verticals heavily reliant on fax technology for their business operations. IDC states that approximately $110 billion was spent on fax telecom services in 2002. Fax accounts for 40-50% of the telephone bill for many organizations with overseas business units.

The emerging VoIP and still stalwart fax services have proven to be poor dancing partners. Fax is a real-time service optimized for the Public Switched Telephone Network (PSTN). But over an IP packet network, fax quality is compromised by lost packets, network delay, jitter, and out of sequence packets. This results in terminated sessions, additional bandwidth requirements, and reduced fax readability at the receiving end. In response, the industry has developed the T.38 standard specifically for real-time fax transmission over an IP infrastructure. This technique is known as Fax over IP (FoIP). It requires a T.38 gateway at each end, retraining of office personnel on fax operation, and connecting low-cost fax machines to $500+ T.38 gateways. Alternatively, the enterprise can replace working fax machines with their more expensive T.38 FoIP counterparts.

The business case for FoIP is further hampered because T.38 remains immature, with interoperability problems among the T.38 vendors (though this inconvenience is being reduced over time). For these many reasons, FoIP is not viewed as a viable alternative by the vast majority of fax users. The bottom line is that FoIP is a headache that we can all do without. The T.38 option is not practical given its limited adoption and uncertain future. The market prefers traditional PSTN faxing by a wide margin, especially as long distance PSTN costs continue to decline.

Given the current environment, most enterprises running VoIP adopt parallel networks similar to the one shown in Figure 1. There is a T1 line connected from the VoIP PBX to the PSTN to support packet voice. This is complemented with four parallel POTS lines to support the fax service. Even small-medium sized enterprises, with as few as 50 employees, have multiple fax machines so that they are physically close to the staff. Assuming that each POTS business line costs $65 per month, this results in a charge of $260 per month for the four lines. The enterprise pays $3,120 per year in this example, just for fax access!

PotsTek has developed a better mousetrap with its Vplex solution, illustrated in Figure 2, which integrates fax with VoIP, and potentially other data services. The enterprise connects standard Group 3 fax machines to the POTS lines supplied by the Vplex. Any of today’s common fax machines are compatible, with pricing starting as low as $100, to over $1,000 for the more sophisticated units. The Vplex can be configured for one to four fax lines, enabling the enterprise to locate each fax machine close to its users.

The Vplex integrates the fax lines with the output of the VoIP PBX, sending the combined services over a standard T1 line. The T1 is channelized so that each individual fax and voice session is independently routed to the destination. Configured with four analog active ports for fax, over 1.2 Mbps remains available to IP traffic. Supporting fax services over the Vplex T1 is superior to relying on individual business lines. T1 is a carrier class service, complete with Service Level Agreement (SLAs), sophisticated monitoring systems, and guaranteed mean-time-to-repair (MTR) metrics. A T1’s MTR guarantee may vary between providers, but is typically about 4 hours whereas individual business lines often have a 24-hour MTR. Additionally, T1 pricing continues to erode in order to stay competitive with its lower quality DSL colleague.

The Vplex provides the enterprise with three primary benefits. First, it allows those businesses committed to VoIP to leverage all of its digital advantages while continuing to secure standard reliable fax service. There are no obstacles to exchanging faxes with the legions global fax users, ranging from individual consumers to multi-billion dollar business partners seeking a quick legal signature.

The second benefit is that all office equipment (phone, fax, computer, printer) continues to perform as they always have. There is no learning curve or additional distractions for the office staff. The third and final benefit is cost savings. Enterprises may significantly reduce telephone costs. In this example, the enterprise saves $3,120 annually by integrating the fax service onto the T1, enabling it to cancel the four separate POTS lines supporting fax services. Vplex users could end up achieving a positive ROI well within six months.

VoIP is on its way while fax is here to stay. Vplex provides the capability to support these trends. A sensible FoIP solution is not on the horizon, in part because few organizations support the T.38 standard. PotsTek has developed an elegant solution that cost effectively supports VoIP and traditional fax over a single T1 line. Our solution is extremely practical, empowering enterprises of all shapes and sizes to transition to VoIP, without encountering excessive fax access charges or transmission aggravation.