Understanding your storage and bandwidth requirements can be one of the most challenging aspects of deploying an IP video surveillance solution.
Because IP cameras can use between 10 to 15 times more bandwidth than analog cameras, businesses deploying IP solutions sometimes find it difficult to view surveillance images from remote locations. High-speed Internet may not always be available or bandwidth may be limited because other essential applications like VoIP and transaction data will take priority.
One great option to optimize your bandwidth without sacrificing high-quality surveillance images is to use alternate stream recording.
What is Alternate Stream Recording?
Alternate stream recording is your IP camera and networked video recorder (NVR) or video management system (VMS) working together to record two separate streams of video simultaneously. One stream can be recorded at low resolution, to enable easy viewing over the Internet, while the other stream can be recorded at a higher resolution and frame rate for local viewing and investigation purposes.
For example, a retail business that wants to keep a close eye on its point-of-sale (POS) systems could set up an alternate stream on the IP camera over its cash registers.
The primary stream could be set at 2 megapixel resolution, with frame rates of 5fps, while the alternate stream could be recording at a much lower resolution such as CIF or 4CIF. The bandwidth for the alternate stream could be well under 256 Kb/s.
Security officials, who need to regularly monitor cash registers, can easily view the low resolution images over the Internet and quickly scan for suspicious activity. If something unusual is spotted, they can download the high-definition video from the primary stream and do a closer, more detailed inspection.
It’s important to note that alternate stream recording can impact your storage capacity. Additional hard-drives can assist. However, businesses deploying multiple IP cameras are likely to have budgeted for additional storage anyway, and an alternate stream recording at a low resolution won’t add significantly to your overall space requirements.
Since many factors – like the number of cameras you are using, your choice of settings and your video compression technology – all impact storage and bandwidth, you need to think carefully about your security requirements to ensure you allocate resources appropriately and don’t overwhelm your network.
One way to easily calculate your bandwidth and storage needs and assess the impact of setting up an alternate stream is to use our System Design Tool. Just input the number and types of cameras you’d like to deploy, along with your preferred storage length, compression, frame rate and resolution, and the tool will give you the bandwidth and storage required for the job.