Dealing With the ‘IP’ in IP Cameras

As the demand for remote capabilities is on the rise and the IP industry evolves, many are chasing the “total” IP solution. Once a novelty, IP-based streaming video is poised to become an application enterprise to distribute camera images across networks for security applications. While the networking of security equipment is obvious, the question still remains, Should IP begin at the camera or at the recording device?

For the past few years, our industry has taken great strides toward embracing IP technology, and many major CCTV manufacturers have introduced lines of IP cameras. At the same time, the industry has paved the way for a whole new litany of potential errors and misconceptions.

Many will argue that while IP cameras’ costs are three to four times more than the average analog unit, the overall system will cost less because the cabling infrastructure already exists. Although plugging a camera into an open network port sounds like a great idea and certainly would simplify the installation, the question remains: How many cameras an existing network can support?

A typical IP camera may produce a video stream up to 5MB. The first hurdle to overcome would be the bandwidth bottleneck. Video streams have been known to clog shared 10/100MBps local area networks (LANs).

Many will argue that switched LANs and fiber backbones will open the bottleneck to offer gigabit LANs. The reality is that less then 10 percent of networks currently installed have gigabit capabilities.

How much bandwidth do you need? Streaming video requires a large amount of bandwidth. A single video stream usually requires a minimum of 384Kbps of bandwidth to support what is considered acceptable video. An additional 10 percent of headroom is recommended to ensure an uninterrupted video stream.

Guidelines Pave Clear Data Path
Many IT managers will attest that not only will this increased amount of traffic hinder their data network, but additional problems can also compromise network performance. Many clients encounter distributed denial of service (DDoS) attacks to their network. The problem is bandwidth consumption and useless traffic, which can consume bandwidth.

Many network specialists have determined that DDoS attacks can occur from not only malicious behavior, but also from a malfunctioning network devices such as printers, fax machines or improperly terminated network cables.

Due to network latencies, the Electronic Industries Alliance (EIA) and Telecommunication Industries Association (TIA) have set forth guidelines to ensure moving data is error-free and gets to its destination as quickly as the network will allow. The horizontal cable that will connect to the camera cannot exceed 295 feet. This is significantly less then the average security cable run of 500 feet.

Causing a Network Traffic Jam
When it comes to network traffic, what gets priority?

The precedence bits are set in the IP header. The type of service byte dictates what gets priority. The higher the number, the greater the precedence one packet has above the other.

Due to the sensitivity of voice and video packets in relation to data packets, video is given a precedence of 4, and data a precedence of 0. This ensures video packets are given priority ahead of data at a bottleneck point in the network.

When data and video streams are sharing the same network infrastructure, their divergent requirements conflict. Congestion will slow down the network device, forwarding a large file transfer and a video stream. While this causes no great problems for the data transfer, it creates havoc with the video stream.

Seemingly, the only approach to guarantee clean video is to overbuild the network, providing more then enough bandwidth. However, this network overhaul seemingly cancels out the cost savings associated with IP cameras.

What about multicasting? Will this save bandwidth?

Many skeptics will contend that bandwidth consumption is not as much of an issue due to multicasting. While conventional packet data is normally sent from one source to one destination. Multicast traffic is sent from one source to multiple destinations without consuming any additional bandwidth. The source delivers packets to the network switch and the switch reproduces the packets and delivers them to anyone connected who requests them.

This would work great for a single IP-camera application. However, in a 16-camera application, we would have 16 devices streaming packets to a single switch. More Burdens to Lay Down
Many affordable IP cameras offer reduced frame rates and resolution to keep bandwidth consumption to a manageable amount. Even if the bandwidth issue is conquered, there are other obstacles ahead once the images have reached the servers.

There’s still the matter of managing all the IP addresses, retrieving the stored images and viewing more than one camera at a time.

With streaming video, a user can request video from a camera on the network without downloading a file.

Instead, the media is sent in a continuous stream and played as it arrives. The user who is requesting the file must have a viewer or browser that can uncompress and display the video. Analog’s Legacy Lives On in IP
From the CCD (charge-coupled device) sensor chips all the way to the PC board, video imaging is still quite simply the same analog device we have been using for the past 20 years.

The only difference is the video compression device that is used to convert the analog video output to digital. In addition, formatting digital video into a streaming format is processing intensive. Setting up servers to handle the large volume of streaming video is tough on the budget.

When reviewing the specifications of the most popular IP cameras available today, you have to ask yourself, “What do they offer that I am not getting from my traditional system?”

One of the largest advantages I see in an analog video system is system reliability. If a network switch fails, the images will still be recorded.

Computers have become an essential tool in our daily lives. As we all can attest, just as they make our lives simpler, they also challenge us daily with software updates, viruses, system crashes and software failure.

Before we begin tossing the elderly aside to implement the latest IP technology, we should ask ourselves: Have we removed the “security” from our video security system?

Chad Szerkes is the national sales manager for Nitek.


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