The article reports on the threats of VoIP (Voice Over Internet Protocol) system and IP (Internet Protocol) telephony among small and medium businesses (SMBs). The threats of VoIP system are categorized into "D" threats and "P" threats. "D" threats are VoIP attacks which disrupt, disable, and destroy data systems through SPIT (Spam over Internet Telephony). "P" threats are attacks against privacy of business IP telephony systems through wire-tapping. They can be prevented by businesses by using IP PBX, a managed services solution which provides LAN and WAN security controls. They can also be controlled by having a VoIP system or service with voice-only proxy firewall and session border controller.