When I pick up my telephone, I can call anyone in any company or any home in the world. But my enterprise video conferencing system can often only connect to video systems that are within the same enterprise. Yes, we can sometimes connect across the open Internet as well, but users know this is hard to set up, and often has lower quality or poor performance due to the lack of QoS and guaranteed bandwidth. It works on a good day, but cannot be guaranteed for enterprise-class performance. Why is there this difference between video and voice? And how can we solve it?Let's look at how we got here. Ten years ago, most enterprise video conferencing systems could connect with other enterprises because they were connected to the PSTN using ISDN for transport. They behaved just like telephones, in that they dialed telephone numbers, and were connected through the PSTN to other video endpoints. Yes this approach was complex, prone to connection problems, hard to debug and support, especially across national boundaries, and limited in bandwidth. But it worked, and it still works today. Many enterprises still rely on ISDN to support business to business video calls and to support video to regions of the world with poor IP network connectivity.
As video conferencing technology and IP networks improved, we moved to IP-based conferencing. The newer High Definition codecs provide much better resolution and motion, providing a much higher quality video meeting experience. IP-connectivity also allows other forms of simultaneous interaction such as data sharing, wide-band audio and smart boards, providing a more interactive and productive meeting. To get this high quality we have increased the bandwidth used by video, and migrated it onto our IP networks.
Converged networks has been the battle cry for the last decade as we integrate voice and video conferencing onto the same network that carries our data applications. Quality of Service, discussed at length in my postings, helps us to provide the right performance for each application type on this converged network. Cost is reduced. Management is simplified. Goodness all over. So what happened with business to business video?
The downside of the technology migration of video has been its need for additional bandwidth. This bandwidth demand has meant that ISDN is no longer a great solution for business-to-business (B2B) conferencing. ISDN provides multiple discrete 64K channels. The complexity of bonding 6 channels to support a 384K conference was bad enough. Trying to support the bonding of 16 channels or more required for high definition calls is just too difficult, too expensive and unreliable.
The natural answer is the Internet, our world-wide IP connection. But the Internet has a couple of key disadvantages. Firstly, we have to hide our enterprise networks behind rigorous firewalls to protect our data and data applications, and firewalls are not well suited to passing voice and video traffic. Secondly, the Internet has no support for QoS or guaranteed bandwidth, so we can not be assured of the quality of our B2B video conferencing calls. Partial solutions for these problems exist today, but as yet we have no consistent dependable solution.
Voice has not suffered from this issue because the ubiquitous PSTN acts as a central meeting place for any VoIP deployment, and because the bandwith requirement for voice has not changed. We are bypassing the PSTN more and more with SIP trunking, but it continues to act as the default meeting point for full world connectivity. Because there is no additional bandwidth required for voice today than there was in 1970, the design of the PSTN still suffices for this interconnect.
In my next few postings I hope to outline the requirements for a B2B video conferencing and telepresence solution, review what the industry is doing today and show how I think this will evolve going forward. Video conferencing / Telepresence is destined to become a mission-critical capability for many enterprises, and will soon see demand in the consumer market as well.
