D-Link Port Forwarding of DVR

D-Link Port Forwarding - DIR 615 - DIR-825 - DIR-655 - DIR-628 - DIR-628

D-Link port forwarding, also known as virtual server, allows you to configure inbound Internet connections to your router to be routed to specific devices on the network.  In order for surveillance system cameras to be accessible over the Internet, your router is configured to forward requests to your surveillance DVR or directly to IP cameras.  The IP address that your router assigns to your DVR or to IP security cameras is a LAN (internal IP address) that cannot be accessed from outside of your local network.

These instructions are for more recent D-Link routers such as the following: DIR-615, DIR-825, DIR-655, DIR-628.

1.     Open your D-Link router's control panel by going to the IP address http://192.168.0.1/ in a web browser. You will be prompt for a password.  If you did not setup a password on your router, the dlink default password is usually blank.  Enter admin for the username and leave the password blank or enter your password.

2.     After you are logged into your router

1. Click on the "Advanced" tab (#1 below). The virtual server screen will open.

2.     Click the check box next to the first open virtual server entry and fill in the Name for this service.  This can be anything that you choose.  Also fill in the IP address of the device that you are setting up port forwarding for.

3.     Enter the port # for both the Private Port and Public Port.  Ports 80, 4550, and 5550 are the ports that need to be forwarded for Some DVR webcamserver to work.  You need to make an entry for each port.  Most of our stand alone DVRs only use one port which should be supplied on the instructions for the particular DVR you are installing.

4.     Select "TCP" for Protocol.

5.     Select "Always" for Schedule, and "Allow All" for Inbound Filter.

6.     Click Save Settings.

2.     On success, the screen will display a settings saved screen

The port forwarding entry is now added.  If you need to add additional port forwarding rules, repeat the above steps.

32-bit and 64-bit CPU

If you are CCTV technicians you need to know the two main categories of processors are 32-bit and 64-bit. The type of processor a computer has not only affects it's overall performance, but it can also dictate what type of software it uses.

32-bit processor

The 32-bit processor was the primary processor used in all computers until the early 1990s. Intel Pentium processors and early AMD processors were 32-bit processors. The Operating System and software on a computer with a 32-bit processor is also 32-bit based, in that they work with data units that are 32 bits wide. Windows 95, 98, and XP are all 32-bit operating systems that were common on computers with 32-bit processors.

64-bit processor

The 64-bit computer has been around 1961 when IBM created the IBM 7030 Stretch supercomputer. However, it was not put into use in home computers until the early 2000s. Microsoft released a 64-bit version of Windows XP to be used on computers with a 64-bit processor. Windows Vista, Windows 7, and Windows 8 also come in 64-bit versions. Other software has been developed that is designed to run on a 64-bit computer, which are 64-bit based as well, in that they work with data units that are 64 bits wide.

Differences

The main difference between 32-bit processors and 64-bit processors is the speed they operate. 64-bit processors can come in dual core, quad core, and six core versions for home computing (with eight core versions coming soon). Multiple cores allow for increase processing power and faster computer operation. Software programs that require many calculations to function operate faster on the multi-core 64-bit processors, for the most part. It is important to note that 64-bit computers can still use 32-bit based software programs, even when the Windows operating system is a 64-bit version.

Another big difference between 32-bit processors and 64-bit processors is the maximum amount of memory (RAM) that is supported. 32-bit computers support a maximum of 3-4GB of memory, whereas a 64-bit computer can support memory amounts over 4 GB. This is important for software programs that are used for graphical design, engineering design or video editing, where many calculations are performed to render images, drawings, and video footage.

One thing to note is that 3D graphic programs and games do not benefit much, if at all, from switching to a 64-bit computer, unless the program is a 64-bit program. A 32-bit processor is adequate for any program written for a 32-bit processor. In the case of computer games, you'll get a lot more performance by upgrading the video card instead of getting a 64-bit processor.

In the end, 64-bit processors are becoming more and more commonplace in home computers. Most manufacturers build computers with 64-bit processors due to cheaper prices and because more users are now using 64-bit operating systems and programs. Computer parts retailers are offering fewer and fewer 32-bit processors and soon may not offer any at all.

Bit Rate

Bit Rate For DVR, NVR & IP Camera

What are Bit Rates?

Let’s start with “what is a bit, and “why do I need to know?” A bit is short for “binary digit”, the smallest unit of information in computing. It takes 8 bits to make a byte of information. “Bit rate” refers to the number of bits of data transferred in a file over a set length of time usually measured in number of “bits per second” or “bps”.

Constant bit rate (CBR) and variable bit rate (VBR) are the main types of bit rate encoding. Scene complexity can vary significantly over several hours of recorded video, and the bit rate you select for recording will have an effect on image quality, bandwidth consumption, and hard drive storage. A complex scene with moving action, such as traffic on a city street, or a scene with a lot of contrasting colors, will affect image quality and bandwidth consumption more than a less complex scene, such as an interior room with very little action or movement.

Most NVRs and IP cameras let you choose either constant or variable bit rates for recording video, and this is why you “need to know” the difference.

Constant Bit Rate (CBR)

With constant bit rate encoding, a fixed bit rate and bandwidth is used throughout the entire encoded video file. With a constant bit rate, image quality may fluctuate over the course of the video stream because some scenes are more difficult to render than others. In order for the bit rate to remain constant, the video may be encoded with fewer bits in some places or more bits in other places resulting in inconsistent image quality. Since bandwidth consumption with constant bit rates does not vary, the file size is limited and more predictable than with variable bit rates.

You will most commonly use CBR to restrict the data flow to keep network utilization as low as possible. If you have 10 cameras set to 8000K (8 megabits) on a 10/100 LAN, you are using 80% of your available bandwidth. With CBR, you can set that bit rate down to 5000K and your utilization will be around 50%.

Pre-planning your security video storage requirements is easier with constant bit rate because the amount of data being recorded never changes.

Variable Bit Rate (VBR)

With variable bit rate encoding, a changeable bit rate and bandwidth is used throughout the encoded video file. The variability of bit rates allows for video to be recorded at a lower bit rate when the  scene on screen is less complex and at a higher bit rate when the scene is more complex. Complex scenes (such as moving traffic) require more data and greater bandwidth to maintain image quality  than less complex scenes such as a wall or hallway with very little movement or action. With variable bit rates, the quality of video is higher and more consistent throughout the video stream compared to constant bit rates, yet the file size is less predictable.

Image quality is better with variable bit rates than with constant bit rates, yet pre-planning your security video storage requirements is more difficult because the bit rate changes and more complex scenes will require greater bandwidth and storage.

Here’s a Quick Look at How Constant and Variable Bit Rates Compare:

Constant Bit Rates	Variable Bit Rates
Variable video image quality	Consistent video image quality
File size is predictable because bit rate and bandwidth consumption is fixed	File size is unpredictable because bit rate and bandwidth consumption varies
Greater compatibility with most systems (compared to variable bit rate)	Less predictable compatibility (compared to constant bit rate)
When to use: When you need to limit file size and the quality of video is less important.	When to use: When consistent image quality is critical and predicting or limiting file size is less important.

The best of both worlds is when the device allows you to set VBR with a ‘Cap’ or maximum allowed bit rate.

Here is a handy ‘Quick Reference’ for setting a constant Bit Rate in bits per second.

Low Activity
Compression	Frame Rate	VGA/D1	720P/1.3MP	1080P/3MP
H.264	25~30	768K	2000K	3000K
	15~20	512K	1500K	2000K
	8~10	386K	1000K	1500K
	2~5	256K	768K	1000K
MPEG4	25~30	1000K	3000K	5000K
	15~20	768K	2000K	4000K
	8~10	512K	1500K	3000K
	2~5	386K	1000K	2000K

Normal Activity
Compression	Frame Rate	VGA/D1	720P/1.3MP	1080P/3MP
H.264	25~30	1000K	3000K	5000K
	15~20	768K	2000K	4000K
	8~10	512K	1500K	3000K
	2~5	386K	1000K	2000K
MPEG4	25~30	1500K	4000K	6000K
	15~20	1000K	3000K	5000K
	8~10	768K	2000K	4000K
	2~5	512K	1500K	3000K

High Activity or PTZ on Tour
Compression	Frame Rate	VGA/D1	720P/1.3MP	1080P/3MP
H.264	25~30	2000K	4000K	6000K
	15~20	1500K	3000K	5000K
	8~10	1000K	2000K	4000K
	2~5	768K	1500K	3000K
MPEG4	25~30	3000K	6000K	8000K
	15~20	2000K	4000K	6000K
	8~10	1500K	3000K	4000K
	2~5	1000K	2000K	3000K

In the bit rate charts above, you will see 1000K / 2000K etc. These figures can be loosely translated into ‘megabits’ per second.

1000K = 1Mb | 2000K = 2Mb and so on.

(In the computing world you would actually use 1024K = 1Mb and 2048K = 2Mb, but since most CCTV devices won’t allow those exact numbers, we just round them down to the closest thousand.) These figures are important to familiarize yourself with to manage your network load.

For example – 1 camera running a high bitrate of 8000Kbps (8Mbps) is no problem on a 10/100 network. 10 cameras at that bit rate = 80Mbps. 80Mbps is 80% network utilization on a 10/100 LAN. This is enough to see visible slowdown on the network and may begin to cause problems.

Switch to a Gigabit LAN and that becomes 8% utilization. Always check the capabilities of the network you are installing on – this can save you from a lot of headaches. When using IP cameras, always use Gigabit routers and switches when possible.  Also, make sure your NVR is connected to a gigabit switch. Plugging your NVR in to a 10/100 switch will limit your NVR to a 100Mb connection.

And finally – here is a “loose rule of thumb” for setting a bitrate:

[image width] x [image height] x [framerate] x [motion rank] x 0.07 = [desired bit rate]

Where the image width and height is expressed in pixels, and the motion rank is a number between 1 and 4. 1 being low motion, 2 being medium motion, and 4 being high motion (motion being the amount of image data that is changing between frames.).

So for instance, if we take a 1280×720 video at 24 FPS, with medium motion (movie with slow camera movements, not many scene changes…), the expected ideal bit rate would be:

1280 x 720 x 24 x 2 x 0.07 = 3,096,576 bps => approximately 3000 kbps, or 3MB

Remember – bit rates are not “universal” – different cams will give different results due to variations in encoding methods, hardware, and environmental conditions. Watch for artifacts like “ghosting” or “smearing” of moving objects.

Ghosting = when someone moving across the image may appear transparent, or may have a “ghost” following them. The “ghost” is not always transparent and may look like two people overlapped.

Smearing = when a moving object causes objects around it to change in appearance or starts to become pixilated.

Pixilated = When objects become unclear – may appear as a “smear” or slightly out of focus. In worst cases you will begin to see blocks of similar colors instead of the object itself.

Now that you've learned the details about bitrate and how to tune your IP camera, it's time to put that knowledge into practice. To do this, simply go to the menu of your IP camera and play with the configuration.

In the examples used in this article there was no bitrate limitation, note that the value was always left at maximum (30.720Kbps) so that the camera could use as much as needed according to parameter settings (resolution, frame rate and compression).

Obviously it is possible to do the opposite and adjust the maximum bitrate that the IP camera can use and there will be a "bottleneck" for the image quality, because the camera will reduce the mentioned parameters to fit the chosen bitrate.