Eric W. Keipper

February 28, 1999

"Convergence won’t come easy for Cisco, others"

The volume of network traffic is increasing at tremendous rates. The reason for this exponential growth can be attributed specifically to data traffic. Although voice traffic is also on the rise, it is only marginal when compared to data. Most of the data transmitted is across IP packet switched networks. Voice communication, however, has traditionally be transmitted through circuit switched networks. As the volume of traffic and investment in IP networks vastly surpasses plain old telephone service (POTS), it will become increasingly beneficial to offer voice service over IP networks. This will allow integration of data and voice networks.

However, there are many obstacles that must be over come in order make this service available and deliver the equivalent quality of service (QOS). The main difficulty is in timing. In a packet switched network, packets are not necessarily received in the same order and are delivered in intervals. Each packet could contain 20 milliseconds of speech. This allows for bumps in communication that can clearly be noticed by the human brain.

Cisco is clearly the leader in making this technology a reality. Cisco has come up with the IPv6 protocol that allows packet receivers to set aside resources for regular data flow from a specified source. However, hardware manufactures have yet to agree on how requests will be signaled and coordinated. In addition, it will be difficult to coordinate the sessions through chains of several routers. Cisco has recently acquired Selsius Systems Inc. and Summa Four Inc., which should help them get an edge in the race for QOS level voice over IP.

"Convergence won’t come easy for Cisco, others", PC Week, February 22, 1999 http://www.zdnet.com/pcweek/stories/news/0,4153,391154,00.html