IP Telephony (or VoIP) is a popular choice because of the efficiency and cost savings that it offers. However, simply replacing one technology with another does not remove the risks posed; it just introduces a different set that must be guarded against.
Concerns include protecting against voicemail hacking and fraudulent calls, VLAN hopping and poor configuration of call servers.
NTA's IP Telephony (VoIP) security assessment provides a review of the configuration of the IP telephony system to determine if the voice and data networks are exposed to security threats.
War Dialling - With all the focus on state of the art firewalls and perimeter security devices, it is easy to overlook the PABX telephone exchange as a source of a potential breach. An assessment by NTA will check whether any of your telephone numbers provide a backdoor into the network.