A number of installation problems encountered when installing a DVR are related to the Internet connection. When making the initial specification for a video surveillance installation consider the following:

Dedicated Circuit

Any video surveillance system will demand a reasonble amount of bandwidth during normal usage. Also, the video system will need to be addressable from the Internet as described below. For these reasons, a small or medium sized company should consider a dedicated DSL or other broadband connection to support the video surveillance system. Although obiously an added cost, the system will be easier to install and maintain if it has its own circuit.
DHCP versus static IP addressing
Broadband Internet connections come with either a DHCP or static ip address. If it all possible, it is recommended that a static IP address is used. DHCP can be used, but requires additional configuration and usually the "Terms of Use" of the network carrier prohibit these configuration changes.