You'll also need modems to connect to your phone lines or network adapters to enable the communications link. Best to hire a consultant to do your installation, unless you have expertise on staff. Much of this gear isn't new, and vendors are getting smarter about how it is packaged to make it easier to setup and install. Different products support a different combination of computers, video gear, and communications links. Each video conferencing product is different.
Installation can also be tricky.
We had better experience with our Los Angeles office, where the line has worked well without any glitches. John Hogan also has had better luck with ISDN in Northern California, where his mortgage company is based. And, as long as we are doing local calls, we don't pay more for an ISDN call than a normal local call, which is just pennies a minute. If your firm has already installed some kind of digital phone service connecting your offices for voice purposes, you may be able to piggyback a video conferencing link on top of these connections for minimal incremental cost. Picking the right telephone connections will require some skill and careful planning, and you may need a consultant to help navigate it all.