Network Cameras, IVMS and Firewall

* Network cameras

A network camera, often also called an IP camera, can be described as a camera and computer combined in one unit. The main components of a network camera include a lens, an image sensor, one or several processors, and memory. The processors are used for image processing, compression, video analysis and networking functionalities. The memory is used for storing the network camera’s firmware (computer program) and for local recording of video sequences.

Like a computer, the network camera has its own IP address, is connected directly to a network and can be placed wherever there is a network connection. This differs from a web camera, which can only operate when it is connected to a personal computer (PC) via the USB or IEEE 1394 port, and to use it, software must be installed on the PC. A network camera provides web server, FTP (File Transfer Protocol), and e-mail functionalities, and includes many other IP network and security protocols.

A network camera can be configured to send video over an IP network for live viewing and/or recording either continuously, at scheduled times, on an event or on request from authorized users. Captured images can be streamed as Motion JPEG, MPEG-4 or H.264 video using various networking protocols, or uploaded as individual JPEG images using FTP, e-mail or HTTP (Hypertext Transfer Protocol). More on video compression formats and networking protocols.

In addition to capturing video, Axis network cameras provide event management and intelligent video functionalities such as video motion detection, audio detection, active tampering alarm and autotracking. Most network cameras also offer input/output (I/O) ports that enable connections to external devices such as sensors and relays. Other features may include audio capabilities and built-in support for Power over Ethernet (PoE). Axis network cameras also support advanced security and network management features.



*IVMS

IVMS stands for Intelligence Video Management System.

A video management system, also known as video management software or a video management server, is a component of a security camera system that in general:

- Collects video from cameras and other sources

- Records / stores that video to a storage device

- Provides an interface to both view the live video, and access recorded video

A VMS can be the software component of a network video recorder and digital video recorder, though in general a VMS tends to be more sophisticated and provide more options and capabilities than a packaged NVR device.

Optionally, a VMS may also provide additional features and capabilities. The extent of these capabilities may be divided across several product tiers, with the lower cost VMS products having fewer features.

- Motion detection

Rather than continuously recording data, a VMS may also implement motion detection to reduce the amount of data to be recorded.

Motion detection can now be distributed, so that the cameras do motion detection themselves and only send video when motion is detected.

- Distributed processing

For a very large and complex security camera system, there may be too many cameras, too much network bandwidth, too much data to be analyzed, or too much storage required for a single server device to handle the workload.

In this case the workload is divided across multiple server devices, each handling a slice of the overall workload.

The VMS provides a single management interface allowing clients to access camera sources across all servers, making them appear to be a unified collection rather than isolated on multiple independent sources.

- Audio

A VMS can also be capable of recording audio from network cameras, and may in some cases provide two-way audio through a network camera, acting as an intercom.

Typically this requires an external amplifier and speaker by the camera. Some network cameras include a built-in microphone, or may provide external audio I/O connections.

- Alarm I/O

A VMS may provide the ability to monitor alarm inputs and act on them in some manner, including:

- Sending alarm outputs to activate ancillary equipment such as lighting

- Beginning recording on one or more camera sources

- Sending an alert message to one or more people, via email, cellphone SMS, or over the Internet to a client application or mobile phone app.

- Pan Tilt Zoom control

A VMS may also provide the ability to remotely control pan-tilt-zoom (PTZ) cameras, which can be remotely rotated, titled, and zoomed, thereby allowing a single camera to monitor a very large area while also providing detailed views of specific areas of interest.

- License plate detection / License plate recognition

A VMS can optionally provide the ability to locate license plates in its view and capture the plate information from the image, as a form of optical character recognition.

- Hybrid analog / digital recording

An organization can have a significant investment in older analog (NTSC/PAL/SECAM) cameras and associated cabling and power infrastructure. The organization may decide to keep using the older cameras in some locations, rather than replace everything with new higher detail network cameras.

A hybrid system provides for a lower cost transition between analog and digital cameras, allowing the VMS to accept input from either video source type. A hybrid system may use internal multi-input capture cards or external video encoder devices.

- Point of Sale integration

A VMS may offer the ability to be linked to the output of an electronic cash register, displaying the information printed on a sales receipt as text overlaying the camera image. This provides a visual record of the sale, and tracks mistakes or potential theft by employees.

- Fisheye dewarping

As of 2016, this is still a very new component of video management systems and is not yet widely deployed or consistently implemented.

A fisheye camera has a special lens that typically has a 180 degree field of view and can see 360 degrees around the lens. When mounted flat on a ceiling, it is possible for a single fixed camera to see the entire space below it without moving. However the spherical view causes angular distortion of straight lines, giving objects a strange bulged and deformed appearance.

Fisheye dewarping is a technique used by a VMS to take the output of a fisheye lens and mathematically correct the deformed image so that lines appear straight again, and objects look normal. The image is also typically rotated so that all portions of the view appear right-side-up.

- Single recorded stream, multiple views

A feature of some newer VMS is the capability to show multiple camera views from a single recorded stream. This utilizes digital PTZ of high megapixel cameras, and may also be referred to as client-side dewarping for fisheye cameras.

A single camera with a very wide or high resolution field of view is capable of covering two or more areas of interest. This single datastream is recorded only once, but then decoded multiple times by the client viewer software, zooming in on the separate areas of interest while still only utilizing one camera datastream.

This can significantly reduce data storage requirements, where two or more separate cameras would have been used previously. In the case of fisheye cameras, it is possible for one camera to replace 10 or more separate camera views, while only recording the one original panoramic fisheye view.

* Firewall

A firewall is a program or device that acts as a barrier to keep destructive elements out of a network or specific computer. Firewalls are configured (in hardware, software, or both) with specific criteria to block or prevent unauthorized access to a network. They work as filters for your network traffic by blocking incoming packets of information that are seen as unsafe. In large corporations, if a firewall is not in place, thousands of computers could be vulnerable to malicious attacks. Firewalls should be placed at every connection to the internet and are also used to control outgoing web traffic as well in large organizations.

Firewalls use several strategies to control traffic flowing in and out of networks. Packet filtering is when small chunks of data (called packets) are run through a filter and analyzed. Stateful inspection is where the contents of each packet are not examined, but instead key parts of the packet are compared to a database of trusted information, letting through the packets that pass this test. Firewalls can be configured to filter by several variables: IP address, domain name, protocol, port or even specific words or phrases. Though some operating systems come with a built-in firewall, internet routers also provide very affordable firewall protection when configured properly.