This video describes how to configure a Router for PORT FORWARDING , to view your CCTV cameras over internet.
The HTTP port (80) & the Mobile monitor port of the DVR to be configured open to enable internet view.
This video is demonstrated with Linksys router & Bush Plus DVR.
This video also describes how to install applications on your Android or Windows 8 mobile phone for distant viewing.
http://alselectro.wordpress.com/2013/12/01/cctvstep-by-step-guide-to-remote-view-dvr/