Today, most buyers expect a payback in one year or less. A return on investment is often achievable in just a few months if your company makes lots of international calls. The few products in the chart that support analog lines are designed for small offices that only use a few phone lines. More than half of the gateways also feature automatic public switched telephone network fallback. The very need for such phone network backup highlights the comparative frailty of IP telephony systems.
All vendors offer remote management of multiple gateways from a central location.
Because remote sites often lack appropriate technical expertise, this capability merits close examination. Remote diagnostic testing and error-logging capabilities are other important requirements. Look for ease of use and automation as well as comprehensive management capabilities. For example, automatic updating of phone directories throughout the network greatly simplifies the ongoing administration of changes in users and sites. Consider choosing a product with support for SNMP, which is emerging as a de facto standard to facilitate interoperability with other network management systems and devices.