Cost savings is not only driving force for VoIP implementations, enterprises have to consider some business aspects that VoIP can bring about. VoIP creates potentials for applications that could not have been done before. Collaboration, integration, and interactivity between employees and applications are one of several business benefits that enterprises can derive from VoIP adoption. Nevertheless, amid euphoria of VoIP technology, there are three important aspects to look at before a company goes VoIP. In following paragraphs I will summarize aspect of security, stability, and interoperability that play a key role in successful implementation of VoIP.

1. Security

VoIP implementations may expose new security risks and challenges that somehow become greater concern than quality and cost-efficiency among vendors and users. VoIP networks are vulnerable to all same security risks as traditional IP data networks, including:

• Denial of Service (DoS), viruses, worms,
• Toll fraud and unauthorized access,
• Spoofing, and port scanning.

It is recommended that organizations should adopt a layered, defense-in-depth security strategy to address issue with increasing proliferation of new Internet-borne attacks and malicious activities in recent years. In this architecture, network is segmented into secure zones protected by layers of firewall, intrusion prevention, and other security services. This strategy allows organizations to logically split and secure voice and data networks in front of individual voice and data components and between interactive points in network.

2. Stability

One of main issues of VoIP is amount of bandwidth required for each call. There must be adequate bandwidth reserved and quality of link must be well maintained throughout each call to ensure users are not affected. As very nature of VoIP call is real-time, any disruption during call would be easily noticeable and unacceptable. The two issues that enterprises usually have to deal with here are bandwidth and quality of service (QoS).