How much bandwidth do I need at Office Location X?
To get awesome video quality on your endpoint you need to have a Premium subscription. A plus subscriptions give great quality (up to HD).
Bandwidth needs all depends on your office size and how many video systems you have, of course.
As a rule of thumb calculate 3 Mbit/s per Premium-enabled "dedicated video system" you have installed in the Office Location. For a Plus subscription we use 1.5 Mbit/s as calculation value.
In addition, you need to add bandwidth for personal PC/Tablet/Mobile clients as well. However, usage of these is more spread out in time as they are personal. That is why we use an "estimate" of 0.5Mbit/s per active user (3 - 10 users).
Now, most people do not have a dedicated link for video traffic. It is a shared resource, so depending on your other network traffic pattern, we suggest to add some margin to allow for web browsing and other background traffic. This should be about 2Mbit/s at least. If office users use streaming services like YouTube, the margin needs to be even higher (eg 5Mbit/s).
That gives an additional bandwidth required at your location:
3 Mbit/s X Dedicated Video Systems with Premium subscriptions
+ 0.5Mbit/s X Number of personal video users (3-10)
+ 0.3Mbit/s X Number of personal video users (11-50)
+ 0.2Mbit/s X Number of personal video users (50+)
If you have strong peaks in the network usage (like offsite backups) you should consider some way of controlling burst traffic so it does not congest your Internet link.