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Security concerns for VoIP customers

VoIP systems offer cost savings and convenience, but have you considered the security issues of VoIP systems in relation to security alarms and emergency services?

Many businesses and home owners today are attracted to 'Voice over Internet Protocol' or VoIP services from local Internet providers and cable companies. VoIP offers significant cost savings on local and international calls as well as streamlining service providers by utilizing one vendor for both networking and telecommunications. However, most users are unaware of the security issues and vulnerabilities of VoIP systems in relation to security alarms and emergency services.

There are four main areas of concern for security and emergency services that need to be addressed in VoIP deployments: signal distortion, power failure, line seizure and service outages.

Signal distortion
Most alarm systems were designed to transmit alarm signals as a series of beeps and tones over analog phone lines. Digital alarm communicators (DACTs) may not function properly in a VoIP environment. The inherent design of the Internet is that it is optimized for data transmission. It is a 'packet' switched, digital network that was not originally designed for to carry voice traffic in comparison to the PSTN which is a 'circuit' switched, analog network, optimized for voice. Therefore, VoIP technologies need to convert analog tones into bits of data to transmit them over the network, and convert them back to be understood by the receiver.

Converting the signal from analog to digital packets and then translating the digital back to analog again can create distortions and delays. This can cause the alarm signal to be unintelligible by the central monitoring station. The tones and dead spaces between dual tone multi-frequency (DTMF) tones or touch tones and other signaling schemes used by alarm systems may not be recreated accurately. Alternative formats – 10, 20, 40 pulse per second, Contact IS and FSK formats - also encounter transmission problems. Although humans may be tolerant of slight distortions to voice traffic when utilizing VoIP, digital alarm receivers are expecting precise communication.

Power failure
Analog phone lines have high-availability rates during power outages. The telephone line's voltage is generated at the telephone company's central office, which generally has sufficient power backup. However, when VoIP is installed in residences and small offices, it rarely includes on-premise backup power. In the event of a power failure, cable modems and DSL lines will not work unless you have a power backup or a generator. Losing power, can mean losing your communication with the outside world. Not only will the alarm system be unable to communicate with the central station, but customers will not be able to dial 911 or access other emergency services.

Line seizure
Alarm systems are designed with line seizure capabilities – enabling them to take over an open phone line to communicate with the central monitoring station in case of an emergency. Often, the cable company or ISP will actually install the VoIP modem in a residence by 'back-feeding' the house circuit and disconnecting the old telephone circuit as it enters the premises. Because the alarm control panel is configured to have the telephone circuit connected first, ahead of any telephone instruments, it can interrupt and disconnect an existing call to give the alarm signal priority.

Even when the customer has had the alarm company reconfigure the alarm control panel to connect with the broadband line, VoIP has no line seizure capabilities. This means, that if the line is engaged (in use or off the hook) the alarm system is unable to take over the line and send a signal to the monitoring station. If there is an intrusion, fire, or other emergency and the phone is in use (possibly by a burglar taking a phone in the premises off the hook), no alarm signal will be transmitted.

Service outage
Internet service providers and cable companies are also susceptible to service outages. The Internet is not always accessible to transmit your alarm signals. Service outages, server malfunctions, and system upgrades and regular maintenance are just some of the reasons that your VoIP system may not be as reliable as analog phone systems to transmit alarm signals.

Combating VoIP security concerns
In order to combat VoIP security concerns, Supreme Security Systems recommends retaining a basic land telephone line for emergency phone requirements such as calls to 911, medical assistance providers and alarm system monitoring services. If customers prefer not to maintain a land-line in addition to their VoIP service, Supreme Security recommends a long-range radio backup service for extra protection. Radio backup service is available through Supreme and communicates directly with its central monitoring station without relying on third-party service providers.

VoIP offers numerous advantages to residential and commercial users and is proliferating at exponential rates. However, customers need to be aware of how it may negatively impact their security systems. If users are aware of these issues, they can take proactive steps to resolve them before an emergency situation strikes.

About the author:
As Vice President and Chief Operating Officer of Supreme Security Systems, Dave is responsible for the day-to-day operations of the business. Dave provides guidance and oversees a number of internal departments, including operations, IT, customer service and sales to ensure that the strategic plans of the company are integrated into all key functions of the business. Before returning to Supreme in 2002, Dave worked in web application development at Capital IQ, Inc. and BANKLINK, Inc. Dave holds a Bachelor of Science degree in Commerce and Engineering Sciences from Drexel University.

This was last published in February 2005

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