Before selecting a DVR it is important to evaluate if the user interface meets the requirements of the situation. Here are some factors to consider:

Web Interface

Every vendor's DVR has at least some web interface that allows the user to view security cameras remotely. However, some DVRs only only limited functionality when viewing remotely. This is a problem when the DVR is located in a closet or other secure location and is not easily accessible.

In addition, some web interfaces are built using standard web technologies and are therefore accessible from any browser at any time. Unfortunately, the price of nearly universal compatibilty is often the frame rate the web interface can display.

A web interface may also require software or an activex control to be downloaded first. Still others do a mix of different things depending on the situation. All of these have an effect on where and how the system is used.

Multiple Views
At a minimum, a DVR should support viewing multiple security cameras from multiple locations in one view.

Access Control
An enterprise class DVR should support multiple "roles", e.g. security guard, administrator, or guest. Each role should have different access to different views.