Voice over Internet Protocol - technical definition

VoIP calls can be placed through the Internet using a VoIP service provider as well as standard computer audio systems. Alternatively, a service provider can support VoIP through regular telephones with specialized adapters connecting to a computer network.

One big advantage of VoIP is that it is much cheaper placing long-distance calls than when calling the conventional way. Also, Internet telephony services include inexpensive features such as audio-video conferencing, online document sharing, and messaging. The main drawback to VoIP is that there is a greater potential for “dropped” calls (as experienced with cellular phones) and a generally reduced voice quality, as compared to traditional phones.

In terms of security and trust issues, experts caution that VoIP technology could create an enormous market for voice spam (known as SPIT, or spam over Internet telephony). Using automated VoIP servers, telemarketers could transmit messages to thousands of Internet phone addresses simultaneously rather than place each call separately using a traditional phone line. At present, SPIT is not much of a problem because not enough people receive their telephone services over the Internet. Apparently there currently are only about 6.5 million VoIP users worldwide in 2004. Analysts expect that this number will grow to over 26 million by 2008.

In January 2005, a new report from NIST (National Institute of Standards and Technology) cautioned federal agencies and enterprises about changing to VoIP technology because of security issues. The 99-page report entitled “Security Considerations for Voice Over IP Systems” had nine recommendations for IT managers to assist them in implementing the technology in a secure way. For example, the report called for building separate voice and data networks whenever pragmatic instead of building one converged network. The report also stressed that VoIP softphones should not be used when privacy is a key concern, and that VoIP firewalls should be not only used but also routinely tested.

Moreover, in February 2005, a new group formed to investigate cracks that could occur with VoIP. Called the VOIP Security Alliance (VOIPSA), the group is motivated to prevent potential cracks using vulnerabilities found in the protocols enabling VoIP, such as SIP (Session Initiation Protocol) and H.323.

See Also: Internet; Internet Protocol (IP); National Institute of Standards and Technology (NIST).