What are some of the bandwidth issues that must be considered when transporting video surveillance feeds over the IP network?
A. First, let us provide some ranges of bandwidth for different encodings. A Cisco 2500 series SD camera in 4CIF/D1 using MPEG-4 generally a Constant Bit Rate (CBR) value of 1-2Mbps is a good starting point. A Cisco 4000 series HD camera in 1920×1080 (1080p) at a CBR rate of 4 or 6Mbps is a good starting point. In a LAN environment, these data rates are easily handled by the access layer switch and aggregated into the distribution and core layer in the campus. In the WAN, with a T1/E1 link, more bandwidth is required than the 1.5/2.0Mbps for T1/E1. The key is to archive video locally, on the LAN and only transport the video that is needed remotely over the WAN. Q. Regarding the bandwidth and file size of video archives, is it our compression algorithm the challenge with file sizes or do all our competition have the same problem (i.e., is it a standards-based issue rather than a vendor issue)? A. This is a function of the CODECs. All vendors will have this issue. While MJPEG and MPEG-4/
