The distributed nature of video conferencing means that location of equipment can matter. Most video conferencing infrastructure components can be housed in the data center along with other servers, or they can be purchased as an external service. However, the placement of one key element, the video conferencing MCU (multipoint conference unit), requires careful thought.
Before you invest in video conferencing equipment or services, make sure you take the time and trouble to understand your overall video conferencing requirements, choose the type of video conferencing that is most suitable for your company, understand the video conferencing quality you must deliver to users and do your homework to pick the right video signaling infrastructure. Then you can locate your MCU where it will most cost-effectively scale to meet your needs.
A video conferencing MCU is like an audio bridge: It is required for three or more endpoints to participate in the same video conferencing call. The MCU supports a multipoint call by connecting to each participating endpoint and constructing the right combined image to send to each endpoint, enabling all participants to see each other. As the number of participants increases, the number of MCU-connected endpoints increases, creating a bandwidth hotspot.
Locate MCUs in the data center or WAN?
Although it may seem most logical to locate video conferencing MCUs in the data center, because the data center usually has high-bandwidth connectivity, topologically it is wiser to locate MCUs in the WAN core. Video is most often used across long distances over the WAN, and the WAN must support the video conferencing traffic. Therefore, locating the MCU in the WAN core ameliorates the problem of scaling bandwidth to it.
With this architecture, the video bandwidth needed at each office is directly related to the number of simultaneous calls expected from that site, and does not depend on how many other users might be using local resources for a multipoint conference. This design is much easier to manage as your video conferencing deployment grows.
Locating the MCU in the WAN core usually means leasing rack space in a collocation facility. You may already lease collocation space for servers, or you may purchase it through your WAN service or managed video service provider. Finding the right network location for video conferencing MCUs will save bandwidth charges and will allow your video network to scale easily.
Getting your video conferencing deployment right from the get-go may not only be important to your employer, but also to your career. With many top executives increasingly using video conferencing facilities, it is smart to make sure they work as advertised.
About the authors:
John R. Bartlett is a Principal Consultant at NetForecast, where he focuses on network support for voice and video conferencing. NetForecast provides consulting to enterprises and networking equipment vendors on application performance issues and convergence of voice and video conferencing on the IP network. John has 32 years of experience in the semiconductor, computer and telecommunications, and has been consulting since 1996. John can be reached at email@example.com.
Rebecca Wetzel is a principal of NetForecast and a networking industry veteran with unparalleled inside knowledge of the network service and product markets. She works with network product vendors and service providers to develop and implement product strategies. She can be reached at firstname.lastname@example.org.
This was first published in October 2010